University of Nigeria Research Publications

NJOKUOCHA, Reginald C

Aut

hor

PG/M.Sc/92/13365

Title

A study of Vertical Distribution of Airborne Pollen in Nsukka and Pollen Analysis of a Core

From Lake Obayi, Nguru-Nsukka

Facu

lty

Biological Science

Dep

artm

ent

Botany

Dat

e

June, 1997

Sign

atur

e

&\ STUDY OF V E R T l C A L UISTHI .HUT1CN LV AlRBURNE PCLLEN

1 N NSUKKA AND POLLEN A N A L Y S I S b F R CORE F'RUM LAKE

CjBAYI, NGURU - NSUKKA

N J U K U K H A , AEGlNALD CI1UKWbEMEKA

R E G - NU: PG/M-SC/92/12365

D I S S E R T A T I ON S U B M I T T E D 1N PART l A L F'ULF ILMENT

UF' T H E REQUIREMENTS F'GR THE DEGREE OF' MASTER

OF' S C I E N C E 1.N P A L Y N O L G Y AND P A L A E U E C O L W Y

1 N THE DEPARTMENT UF R W A N Y , F ' A ~ U L T Y 01;'

k3 I O L W I C A L S C I E N C E S , UN l V E R S I T Y OF' N I G E R l A ,

N SUKKA, N I C E R I A .

J U N E , 1997

A STUDY OF VERTlCAL O l S T H I B U T l C N CF AIRBORNE PCLLEN

I N NSUKKA AND PULLEN ANALYSlS bF' A CURE F'ROM LAKE

OBAYl, NGURU - NSUKKA

N J C I K U K I ~ A , REGINALD CHUKWliEMEKA

R E G - NO; P C ; / M , S C / g 2 / 1 3 3 6 5

D ISSERTATION SUBMITTED I N PARTIAL F'ULF 1LMEiNT

OF THE REUUlREMENTS F'bR THE DEGREE OF' MASTER

OF S C lENCE 1.N PALYNOLOGY AND PALAEUECOLUGY

I N THE DEPARTMENT OF BUTANY, F'ACULTY OF'

I3 10LOGICAL S C I E N C E S , U N l V E R S l T Y C)F' N I G E R I A ,

NSUKKA, NIGERIA.

N J O K U K H A , H E G l N A L O CHUKWUEMEKA, a p 0 : ; t g r a d u a t e

s t u d e n t i n t h e D e p a r t m e n t o f B o t a n y , and w i t h t h e

Reg . N o . P G / M , S c / 9 2 / 1 3 3 6 5 , has s a t i s f a c t o r i l y

c o m p l e t e d t h e requ irements for t h e c o u r s e and

r e s e a r c h work for t h e d e q r e e of M a s t e r of S c i e n c e

( M m S c ) i n P a l y n o l c q y and P a l a e o e c o l o q y i n t h e

D e p a r t m e n t of H o t a n y . The work embodied i n t h i s

d i s s e r t a t i o n i s o r i q i n a l and h a s n o t b e e n s u b m i t t e d

i n p a r t or i n f u l l f o r any o t h e r d i p l o m a or d e q r e e

o f t h i s or a n y o t h e r u n i v e r s i t y . .

PROF E S S M J e N o C e MADUEWESI 1-1 LAD, DEPARTMENT OF' BOTANY SUPERV lSOR

JUNE, 1 9 9 7

iii.

D E D I C A T I O N

~ e d i c a t e d to my Dear P a r e n t s ,

M R . A N D . M f ? S . t3.U. N J O K U O C H A -

i v .

ACKNOWLEDGEMENT

My p r o f o u n d g r a t i t u d e g o e s t o my s u p e r v i s o r , D r .

C.O.C. Agwu, whose immense g u i d a n c e a n d commi t rnen t t o

t h i s r e s e a r c h saw r n e t h r o u g h . To h i m , I am h i g h l y

i n d e b t e d .

T h a n k s a r e a l s o d u e t o t h e f o l l o w i n g lecturers :

I m f . L.L. Lne-obonq, DK. G.C. Uju and D r . ( M r s . ) 14.0 .

Nweze, f o r their c o n c e r n . My thanks e q u a l l y go t u Mr.

U Z ~ O ~ O , A . a n d Mr. Obu, E. who once w e r l t w i t 1 1 me f o r a

field t r i p , M r . I k e h , V.O.; M r . n k e l u , C.E.; Mr.

Oybonnwya a n d t h e e n t i r e s t a f ' f o f the ~ o t a n . i & l ~ a r d e n

. . S p e c i a l t h a n k s g o t o my f e l l o w p o s t g r a d u a t e

s t u d e n t s : Ameh, G . I . , O n y i s h i , L . O . , ~ w o f i a , G . E . ,

O k o y e , F . I . , Ugwoke, C.E. , D r . E z e a n y i k a , L., Ekwuni f ' e ,

V.C.; Kwaye, R.A., O ~ O ~ O , O.I . , Oko, N . ; O k p o r i e , E. ,

~ u k o r , O., o j i a k o (Mrs.) a n d a h o s t o f o t h e r p o s t g r a d u a t e

s t u d e n t s i n ~ k r u m a h H a l l f o r t h e i r m o r a l s u p p o r t .

I a c k n o w l e d g e t .he a s s i s t a n c e of AnO, F., Mbanu, C.,

I k - e o t u ( a l l g r a d u a t e d ) a n d E s o n w e n e , W.O., N W e Z e , A . E . ;

Oko, L.E. a n d NWankw0, U. f o r h e l p i n g m e i n t h e

c o l l e c t i o n o f my s e d i m e n t s a m p l e .

b

I w i s h t o e x p r e s s my s i n c e r e g r a t i t u d e t o my d e a r

p a r e n t s , M r . a n d Mrs. B.U. ~ j o k u o c h a , f o r t h e i r s p e c i a l

d e v o t i o n a n d h u g e f i n a n c i a l s a c r i f i c e t:o m e f o r t h e

p e r i o d o f t h i s s t u d y . My s i n c e r e t h a n k s g o t o my d e a r

b r o t h e r s : P a t r i c k , R e m i g u s , K i n q s l e y , S t a n l e y and my

sisters: J o s e p h i n e and ~ u g u s t i n a for t h e i r i n s p i r a t i o n s

a n d i n n u m e r a b l e c o n t r i b u t i o n s t o w a r d t h e s u c c e s s of my

s t u d y .

I am e q u a l l y q r ~ t e f u l t o M r . Emekwe, M . , E j i e k p e ,

P . C t , Madti, A,A., A l a r i b e , E - , lqbokwe, V . , AnyanwU, P . ,

f o r t h e i r f i n a n c i a 1 s u p p o r t , and ~n'yanwu, V . ,

O n y ~ n e q e c h a , To, C q b o n n a , E., Madu, C., ~ w a c h u k w u , A . ,

N J n k u o c h a , G., Nwachukwu A. , a n d o t h e r s who e q u a l l y n e e d

m m t i o n .

1 w i s h t o t h a n k M r . N.C.0. U f e l l e a n d Odumcdu,

C.F.R. f o r d o i n g t h e c a r t o g r a p h i c w o r k a n d t h e a b l e

t y p i s t , M r . V.N. A q b o q o , f o r h i s e x c e l l e n t s e c r e t a r i a l

w o r k . To t h e D e p a r t m e n t of B o t a n y , 1 a m v e r y g r a t e f u l .

F i n a l l y , I w i l l c r o w n i t a l l b y g i v i n q t h a n k s a n d

G l o r y t c ) God f o r H i s a b u n d a n t mercies.

NJUKUKHA, R E G I N A L O CHUKWUEMEKA

JUNE, 1997.

v i .

TABLE O F COMTENTS

T I T L E PAGE . . C E R T I F I C A T I O N . . DEDICATION . . ACKNOWLEDGEMENT . . TABLE OF CONTENTS . . ABSTRACT . 9 . . LIST OF TABLES . . L l S T OF FIGURES . . CHAPTER ONE: INTHOUUCTION

CHAPTER TWO : LITERATURE REVIEW . . 2 . 1 AIRBORNE PALYNOMORPHS . 2 . 2 AEROSPORES . . 2 . 3 POLLEN GRAINS . . 2 . 4 POLLEN AND SPORE ALLERGY . . 2 . 4 . 1 HAY FEVER AND ALLERGIC ASTHMA 9 -

2 . 5 POLLEN ANALYSIS OF SEDIMENTS .. 2 . 6 VIRTUES O F LAKE AND OTHLR WATER

SEDIMENTS - 0 0

2.7 GEOLOGY 0 .

2 . 8 CLIMATE

6 2 -9 VEGETATION

v i i .

TABLE LF' CWTEN'I 'S

MWTHLY CbUN'rS Df.' ATMOSPHfiR 1C PC~LLE;N CONTENT AT A HElGHT OF 1.80M ( 1 ~ BUTANlCAL GARDEN) k 'RUM F'EUHUitHY, 1993 Tci JANUARY, 1994) . .

LATE DRY S E A S W - RAlNY SEA.'r(.;N (MAY TU AUGUST) . .

COMPARATIVE EF k LCTS OF' METEORLLCGICAL FACTORS R'r 35M AND 1.80M L44 ATMOSPHER 1C POLLElJ AND SPbRE CONTENT

RAlNF' ALL . . . . TEMPERATURE , , . . RELATIVE HUMlD ITY . . WlNO SPEED ..

ix.

TABLE OI;' C W T E N T S -

4 . 8 , 1 a GROUP 1: RAINFOREST TAXA . 4 . 8 . lt) GROUP 11: SAVANNA TAXA

4 . 9 . 4 POLLEN ZLNE 111

5 . 1 POLLLN GRA.LNS TRAPPED A T HE ~ G H ' I ' S 01. 15M AND 1 .80M .

5 . 2 I; UNGAL SPCHES TRAPPED AT HEIGH't'S UF' 15M ANIJ 1.80M ..

5 . 3 PTER 1UOPH Y T l C SPURES

5 . 4 U 1ATUM . b

TABLE UF' CONTLNTS

5.5 OTHER PARTICLES .. 5.6 RCLATlWSt i 1 P S BCTWEEN THE. A1R UbRIdE;

PCILLCN AND SPCJRE C W T E N T S AND METEORLLW l C A L k ACTbHS . .

5.6.1 RAINF'ALL 0 0

5.6.2 T E M P E R A T U R E .. . .

PAGE -

119

x i .

ABSTRACT

T h e s t u d y of a i r - b o r n e p a l y n o m o r p h s t r a p p e d a t

h e i g h t s o f 15m a n d l . B O m , i n U n i v e r s i t y of N i g e r i a , W ~ u k k a

a n d p o l l e n a n a l y s i s of s e d i m e n t s a m p l e s f r o m O b a y i Lake,

N g u r u - N s u k k a h a v e b e e n c a r r i e d o u t . T h i r t y - f o u r p l a n t

f a m i l i e s c o n s i s t i n q of 4 1 q e n e r a were i d e n t i f i e d at_ a

h e i q h t of 15m a n d t h i r t y p l a n t f a m i l i e s c o n s i s t i n g of 3 4

qenera were i d e n t i f i e d a t a h e i q h t o f ?.80m. F o r t y - o n e

, \ r 1 1 1 I or t y - t h r w z l ~ o r P t y r ~ e ~ of f u n g i W P ~ P r ~ c o r d e d af:

v ,Xr inq h e i g h t s of 1 5 m a n d 1.80m r e s p r ? c t i v e l y .

C o r n p a r a t i v e l y , t h e r e war ; a s i g n i f i c a n t d!*f f e r e n r - e

( 1 ' 0 . 0 5 ) b e t w e e n t h e q u a n t i t y . of pol'len t r a p p e d a t

h e i g h t s of 15m and 1.80m, a n d b e t w e e n t h e q u a n t i t y of

f - u n q a l s p o r e s ( P 0 . 0 1 ) t r a p p e d .a t v a r i n g h e i q h t i .

T h r e e " s u b - s e a s o n s " o f re1 a t e d p o l l err a b u n d a n c e h a v e b e e n

r e c o r d e d : 1 D r y S e a s o n ( ~ a n u a r y t o A p r i l ) , ( 2 ) L a t e Dry

S e a s o n - R a i n y S e a s o n (May t o ~ u g u s t ) , ( 3 ) L a t e R a i n y S e a s c n -

E a r l y D r y S e a s o n / \ - l a r r n a t t a n ( ~ e p t e r n b e r t o D e c e m b e r 1.

T h e most a b u n d a n t p o l l e n t y p e s c a p t u r e d a t b o t h

h e i g h t s i n c l u d e P o a c e a e , C a s u a r i n a g u i s e t i f o l i a , M i l i c i a

e x c e l s a , E l a e i s q u i n e e n s i s , C e l t i s r ;p ,A lchornea c o r d i f 01 i a ,

C c y b r e t a c e a a M e l a s t o m a t a c e a e a n d Moraceae. T h e most

a b u n d a n t f u n g a l s p o r e s i n c l u d e D r e c h s l e r a / H e l m i n t h o s g o r i u m

N i q r o s p o r a , U s t i l a q o , E n d o p h r a q m i e l l a , C l a d o s p o r i u m , -

Copr l nus, J o h n s o n ' s smut g r a s s , C u r v u l a r i a , V e n t u r i a and

P i t h a n y c e s . M e t e o r o l o q i c a l c o n d i t i o n s w e r e f o u n d t o

m o d u l a t e t h e q u a n t i t y o f p o l l e n a n d s p o r e s i n t h e

a t m o s p h e r e .

The p o l l e n diagram d i s t i n g u i s h e d four P o l len z o n e s

( 1 - I V 1, considered t o r e p r e s e n t t h e major r e c o q n i s a b l e

c h a n q s s i n v e q e t a t ion . T h e v e g e t a t i o n h a s r e m a i n e d t h a t

ol 4 M V S ~ ~ C s a v a n n a and opc?n forest w o d l d n d . Minor b u t

n o t i c e a b l e c h a n q e s i n t ,he v e g e t a t i o n of t h e area were

dcdl lced f r o m t h e pollen d i a g r a m .

x i i i .

L I S T bF' TABLES

TABLES:

1

2.

3

4

W e a t h e r R e c o r d f r o m F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 . . I n d i v i d u a l P o l l e n a n d P t e r i d o p h y t i c s p o r e s t r a p p e d a t 15m and 1.80m ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) ..

PAGE -

36

M o n t h l y r e c o r d s of p o l l e n g r a i n s t r a p p e d a t 1 5 m ( F e b r u a r y , 1993 t o J a n u a r y , 1 9 9 4 ) 5 3

M o n t h l y records of p o l l e n q r a i n s t r a p p e d a t 1.801n ( ~ e b r u a r y , 1993 t o J a n u a r y , 1994 ) . Tit3

I n d i v idrlal f u n q n l . r p o f ~ s t'o! d l s ,

c o u n t e d a t t h e two d i f f ~ r e n t . h e i g h t s 138

Month ly r e c o r d s of f u n g a l s p o r e s t r a p p e d a t 15m ( F ' e b r u a r y , 1993 t:o J a n u a r y , 1 9 9 4 ) . . 6 3

M o n t h l y r e c o r d s o f f u n g a l spores t r a p p e d a t 1.80m ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) . . 6 7

C o m p a r a t i v e summary of p a l y n o m o r p h s t r a p p e d m o n t h l y a t 15tn and 3.80m ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) .. 7 3

Summary of t o t a1 p a l y n o m o r p h s t r a p p e d f o r t h e o n e y e a r s a m p l i n g p e r i o d a t 15m and 1.80m ( ~ e h r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) . . C o m p a r i s o n of m o n t h l y p o l l e n g r a i n s t r a p p e d a t 15m and 1.80m ( ~ e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) . . . C a n p a r i s o n of- m o n t h l y f u n g a l s p o r e s t r a p p e d a t 15n1 and 1.80m ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 ) ..

x i v .

PAGE I.' I G U H E S :

1

113

l l l b

111

Map of N s u k k a Town s h o w i n q O b a y i guru) L a k e (540.6rn a . s. 1 . ) . . 38

P r o f i l e - S t : r a t i g r a p h i c 1 a y e r s . . 4 1

S a m p l e s A n a l y s e d . * 4 1

M o n t h l y p o l l e n c o u n t s a t h e i g h t s of 1 5 m and 1.801~1 . . 57

M o n t h l y f u n q a l spore counts a t hciqht:r , o t 1 5 m and 1.801~1 . . 6 0

Effect of r a i n f a l l o n f u n q a l spores t r a p p r d / ~ n u n t h at h e i g h t s of 1 5 m and ?*80m r e - 76

Effect o f t e r n ~ e r a t u r e on q u a n t i t y of p o l l e n t r a p p e d a t h e i g h t s of 15rn and 1.80m 7 8

E f f e c t of t e m p e r a t u r e on q u a n t i t y of f u n q a l s p o r e s t r a p p e d a t h e i g h t s o f 35m and 3-80m . . 79

E f f e c t of a v e r a g e m o n t h l y R e l , ~ t . i v e h u m i d i t y on p o l lerr t r a p p e d / m o r r t h l y a t b o t h h e i g h t s .. . 8 1

E f f e c t of a v e r a q e m o n t h l y r c t l , ~ t i v e h u m i d i t y on f u n g a l s p o r e s m o n t h l y a t b o t h h e i g h t s *. . 8 2

E f f e c t of w i n d s p e e d o n p o l l e n t r a p p e d a t h e i q h t s o f 15m a n d 1:80m . . 8 4

E f f e c t o f w i n d s p e e d on f u n g a l s p o r e s t r a p p e d a t h e i g h t s o f 1 5 m . arrd 1.80rn 85

X V .

Poller~ d i a q r a m o f Obayi guru) Lake 93

S e a s o n a l v a r i a t i o n s i n month1 y E l a e i s q u i n e e n s i s p o l l e n c o u n t s o b t a i n e d from 15m and 1.8O1n .. . 10 '3

S e a s o n a l ' v a r i a t i o n s i n m o n t h l y A l c h o r n c a c o r d i f ol i a p o l 1 !.n co1int.s obtained at. 15m and 1 .Horn . . 104

Seasonal v a r i a t i o n s i n m o n t h l y grass (Pnaccae) p o l l e n c o u n t s o b t a i n e d ak 1 5 m and 1 . 8 0 m 1 0 5

CHAPTER ONE

INTRODUCTION

A e r o p a l y n o l o g y i s c o n c e r n e d w i t h t h e s t u d y o f

a i r s p o r a ( p a l y n o m o r p h s ) s u c h a s p o l l e n g r a i n s , s p o r e

from P t e r i d o p h y t e s a n d C r y p t o g r a m s , A l g a e a n d ~ i a t o m s ,

( M o o r e a n d Webb, 1978; M e l i a , 1 9 8 4 ) . A c c o r d i n g t o

L e u s c h n e r a n d Boehm (1977), R o y e s , ( 1 9 8 7 ) and Agwu

a n d ~ s i b e , (1992), t h e a t m o s p h e r e is l a t d e n w i t h

p a l y n o m o r p h s S u s p e n d e d i n a i r t h r o u q h t u r b u l e n c e .

The q u a n t i t y a n d q u a l i t y of these p a l y n o m o r p h s ,

e s p e c i a l l y p o l l e n g r a i n s a n d s p o r e s i n t h e a i r a t a n y

q i v e n time, d e p e n d l a r g e l y o n t h e p l a n t s a n d f u n g i

p r o d u c i n g t h e m , t h e a b u n d a n c e of t h e p l a n t c o m m u n i t y ,

n a t u r e o f p a l y n o m o r p h s , f l o w e r i n g or p r o d u c i n g s e a s o n

a n d t h e n a t u r e of m e t e o r o l o g i c a l f a c t o r s . R a i n f a l l ,

h u m i d i t y , t e m p e r a t u r e , w i n d s p e e d . a n d d i r e c t i o n p l a y

i m p o r t a n t r o l e s i n t h e r e l a t i v e c o n c e n t r a t i o n o f

p a l y n o m o r p h s i n t h e a m b i e n t o a i r . e o l l e n g r a i n s a n d

s p o r e s a r e s u s p e n d e d i n a i r t u r b u l e n c e a n d may be

t r a n s p o r t e d o v e r v a r i e d d i s t a n c e s away f r o m t h e i r

s o u r c e s to o t h e r areas of t h e same o r d i f f e r e n t

e c o l o g i c a l c h a r a c t e r i s t i c s . he q u a n t i t y a n d q u a l i t y b

o f p o l l e n g r a i n s a n d s p o r e s t r a p p e d a t a n y g i v e n

p e r i o d r e p r e s e n t a n e x t r e m e l y s m a l l f r a c t i o n of t h e

p o l l e n a n d s p o r e p r o d u c t i o n a t t h e s o u r c e areas . T h e

t y p e o f s a m p l e r , d i f f e r e n t i a l t r a n s p o r t of p a l y n o m o r p h s

a n d l o n g d i s t a n c e t r a n s p o r t a r e sorne o f s t h e f a c t o r s

t h a t a c c o u n t f o r t h i s v a r i a b i l i t y .

B a s i c a l l y , i n i n t e r p r e t i n g p o l 1 en a n d s p o r e

a s s e m b l a g e , o n e a s s u m e s t h a t a n a b u n d a n c e o f p o l l e n

o r spores of a p a r t i c u l a r t y p e r e p r e s e n t a n a b u n d a n c e

o f p l a n t s t h a t produces t h e m . H o w correct s u c h

i n t u i t i v e i n t e r p r e t a t i o n i s , d e p ~ n d s l a r g e l y on:

L t h e e c o l o q i c a l ( f l o r a l u n d e r s t a n d i n g of

the i n t ~ r p r r t e r ;

i i . h a v i n q a d e q u a t e k n o w l c d r j e o f l o n q d i s t a n c e

t r a n s p o r t and o f m i n o r e l ~ m e n t s i n t h e

p o l l e n s p o r e r a i n , e s p r c i a l l y h e r b a c e o u s

a n d o t h e r p l a n t s of d i s t i n c t i v e

e c o l o g i c a l s t a n d i n g ; a n d

iii. a c o n c i s e p e r c e p t i o n of' t h e d i f f e r e n c e s i r l

p Q l l e n p r o d u c t i o n and d i s s e m i n a t i o n i n t h e

a m b i e n t a i r b e t w e e n v a r i o u s g e n e r a o f

p l a n t s (Moore a n d Webb, 1978).

A e r o p a l y n o l o q y i s a p p l i e d i n m o n i t o r i n q and

, t r a c i n g t h e p o l l e n a n d s p o r e c o n t e n t c f t h e a t m o s p h e r e ,

a n d t h e i r r e l a t l o n s h i p t o e n v i r o n r n e n k a l c h a n q e s a n d

t h e t r a n s m i s s i o n o f c e r t a i n d i s e a s e s of m a n , h i s

d o n l e s t i c a n i m a l s a n d p l a n t s ( ~ e n n i n q h o f f , 1 9 7 3 ; Moore

a n d ebb, 1 9 7 8 ) . T h e p o l l e n a n d s p o r e c o n t e n t o f t h e

a t m o s p h e r e d o p r o v i d e some i n d i c a t i o n s o f t h e

v e g e t a t i o n e x i s t i n g i n a n a rea , t h u s s t u d i e s o f p a s t

p o l l e n a n d s p o r e r e c o r d s c o u l d r e f l e c t v e g e t a t i o n a l

c h a n g e s i n time a n d s p a c e . I t may f o r m a n i m p o r t a n t

basis f o r t r a c i n g c l i m a t i c a n d v e g e t a t i o n a l h i s t o r y

of a n area.

I n a n o t h e r p e r s p e c t i v e , t h e s e p o l l e n and s p o r e s

are p r e c i p i t a t e d f r o m t h e a i r , a n d some d e p o s i t e d i n

water b o d i e s w h e r e t h e y a r e w e l l p r e s e r v e d as f o s s i l s

i n s e d i m e n t s . T h e k n o w l e d g e a n d a p p r e c i a t i o n o f t h e . a n a l y s i s o f t h e s e f o s s i l p o l l e n a n d s p o r e s h a v e a i d e d

i n t h e r e c o n s t r u c t i o n of t h e p a s t v e g e t a t i o n a n d ,

c l i m a t i c c h a n g e s . A s d i r e c t p r o d u c t s o f v e g e t a t i o n

o f c e r t a i n c o n t e m p o r a r y t i m e s , t h e y h a v e b r o a d e n e d

a l s o t h e s c o p e o f u n d e r s t a n d i n g o f v e g e t a t i o n - c l i m a t i c

r e l a t i o n s h i p w i t h i n t h e ~ u a t e r n a r y ( L e z i n e a n d E d o r h ,

A n o t h e r fac tor t h a t h a s i n c r e a s e d i n t e r e s t i n

s e d i m e n t a n a l y s i s i s t h e a v a i l a b i l i t y o f s e d i m e n t b

a g e d e t e r m i n a t i o n s b y r a d i o c a r b o n a n d o t h e r a g e

, d e t e r m i n a n t m e t h o d s . T h e s e a g e d e t e r m i n a t i o n s t a k e n

f r o m d i f f e r e n t l e v e l s o f a core p r o f i l e p e r m i t s

e s t i m a t i o n o f t h e t i m e i n t e r v a l b e t w e e n t h e d e s i r e d

l a y e r s .

I n a n y c a s e , i n a p p r e c i a t i n g t h e r e l e v a n c e o f

p o l l e n a n a l y t i c a l da ta i n t h e r e c o n s t r u c t i o n o f p a s t

v e g e t a t i o n , i t i s i m p o r t a n t t o b e a r i n mind t h a t :

i. v e g e t a t i o n i s n e v e r r e a l l y u n i f o r m b u t s h o w s

g r e a t s p a t i a l i n h o m o g e n e i t i e s i n e s t a b l i s h m e n t

and s u r v i v a l .

ii- he p l a n t communities w i l l n o t react a s a n

i n t e g r a t e d e n t i t i e s t o c l ima t i c c h a n g e , b u t

o n an i n d i v i d u a l i s t i c bases ( L i v i n g s t o n e ,

1 9 6 9 ) .

iii. There c o u l d be m i s l e a d i n g i m p r e s s i o n

e m a n a t i n g f r o m d e p o s i t i o n o f l o n g d i s t a n c e

t r a n s p o r t o f p o l l e n a n d s p o r e s , a n d

c o m p l i c a t i o n s a r i s i n g f r o m t h e p r o b l e m o f

r e d i s t r i b u t i o n a n d r e d e p o s i t i o n o f f o s s i l

s e d i m e n t s b y e r o s i o n (Moore a n d Webb, 1 9 7 8 ) .

'. T h e immense s u c c e s s i n t h e r e a l i z a t i o n o f t h e

o b j e c t i v e s o f p o l l e n a n d s p o r e a n a l y s i s o f s e d i m e n t s ,

stems f r o m t h e h i g h r e s i s t i v i t y of p o l l e n - s p o r e w a l l

t o d e c a y a n d d e g r a d a t i o n b y c h e m i c a l s b e c a u s e o f i t s

s p o r o p o l l e n i n c o n t e n t s ( S o u t h w o r t h , 1 9 7 4 ; Moore a n d

Webb, 1 9 7 8 ; T r a v e r s e , 1 9 8 6 ) .

T h e b e s t e n v i r 0 n m e n t . s s u i t a b l e f o r p o l l e n and

spcre s e d i m e n t a n a l y s i s a r e l z k e s , p o n d s , p e a t b o g s

a n d m a r i n e b e d s , P o l l e n and s p o r e d e p o s i t i o n i n t h e s e

a r e a s a r e n o r m a l l y t h r o u q h f l u v i a l t r a n s p o r t , e r o s i o n

a n d w i n d t r a n s p o r t . I n t h e m a r i n e e n v i r o n m e n t , wjnd

t r a n s p o r t i s c o n s i d e r e d more i m p o r t a n t i n p o l l e n and

spore d i s t r i b u t i o n t h a n o c e a n c u r r e n t - ( D u p o n t and

Aqwu, 1991; D u p o n t , 1993). The d i s a d v a n t a y e , h o w e v e r ,

bcbinq t - t l c l t t h e b i q ~ c . ; k p o l l e n p r o d l ~ c c r s ( a n e m o p h i l o u s

1 ) 1 a n k s ) ,3rc rrror c r e p r e w n t r d i n the clr-earl f l oor , t l i m

t t ~ c a n t e m o p h i l o u s p l a n t s , T h i s i s worse for trees o f

t r o p i c a l f o r ~ s t s l o c a t e d f a r f r c m t h e c o a s t ( D u p o n t ,

1993)

G e n e r a l l y , t h e b a s i s o f s e d i m e n t a n a l y s i s r e v o l v e s

on t h e f a c t t h a t :

( a) p o l l e n g r a i n s and s p o r e s a r e p r o d u c e d a s p a r t of

p l a n t r e p r o d u c t i o n ;

( b ) t h e y c a n b e i n c o r p o r a t e d a n d p r e s e r v e d i n l a k e

muds , p e a t b o g s and o t h e r s e d i m m t s , i n a s t a t e

w h i c h c a n l a t e r be a n a l y s e d t o r e c o n s t r u c t t h e

v e g e t a t i o n of a n a r e a ( ~ e i l , 1 9 8 9 ) .

T h e s t u d i e s of a core p r o f i l e f r c i n O b a y i L a k e

( N g y r u ) and a e r o p a l y n o l o q y o f N s u k k a , t r a p p e d a t

d i f fcrent heights) f o r one y e a r (February, 1993 t o

,January, 1994) i n N i g e r i a w n s aimed at:

i .

IS.

i l t .

i v

V.

r e c o n s t r u c t Ing the r e c e n t ( 4 500yr RP) vecrctnt Ian

(1.1s tr ibut i o n and modern p o l l e n depos-it ion I n

onn?: JAKE ( N W I R U ) N S ~ I ~ ~ R ;

determ1nr)ng the effect a of pame meteorolo,ql.cal

f n - t o r s on the d i s t r i b u t I a n and reY.e~sc of

palynornorpha;

i fetnrmjnfnq the s c a s n n a l pnt t e rn of poll.c?n nnd

spore prescence I n t.hc nt ,monpherc:

edcc?r ' tain3;?~ thr! d l f f r t r n n c e s , if vny, o f pollen

and spore d j ~ t r i b u t l o n n t . two different h e i g h t s :

and

t o e l u c l.do't,e arid c o n t r l b u t e more t o t h e

kriowl edge and und e r o t a n d i n g of the q u a n t i t y

and qriality of palynomorphs i n t h e a i r mnas

of Nsukka.

Thln would be t h e fjrst time the n l r borne p o l l % nnd

opo.rcc cf m y l o c a t i o n for a year i n N l g e r l n h m been

~ t l l d l e d .

CHAPTER TWO

LITERATURE REV lEW

2.1 ,AIR-BORNE PALYNOMORPHS

T h e s a m p l i n g of a i r - b o r n e p a l y n o m o r p h s is an

e n d t o a series of complex r e a c t i o n s or p r o c e s s e s

embodied i n t h e p r i n c i p l e s o f d i s p e r s a l , s u s p e n s i o n ,

t u r b u l e n c e and c o n v e c t i o n , c i r c u l a t i o n and

p r e c i p i t a t i o n .

T h e a t m o s p h e r e a b o u n d s w i t h numerous

s u s p e n d e d p o l l e n g r a i n s , f u n g a l s p o r e s and h y p h a e ,

b a c t e r i a , d i a t c m s , f e r n s , p h y t o l i t h s , a l g a l cells

and f i l a m e n t s , i n s e c t s and i n t e g r a t i n g p l a n t p a r t s

(Moore and Webb, 1978; M e l i a , 1984; Lewis , 1986;

Agwu and O s i b e , 1 9 9 2 ) . T h e s e p a l ynomorphs e x h i b i t

c h a r a c t e r i s t i c a l l y g r e a t d i v e r s e a r r a y s i n s i z e ,

s h a p e , s c u l p t u r e , d e n s i t y , among o t h e r r e l a t e d

q u a l i t i e s (Moore and Webb, 1978 ; Lewis , 1986;

T r a v e r s e , 1 9 8 6 ) - However, e a c h member of a p l a n t

f a m i l y or g e n e r a s h a r e i n common some d i s t i n c t i v e

t r a i t s u s e d t o i d e n t i f y and c l a s s i f y them t o t h e i r

r e s p e c t i v e g r o u p s , b

2.2 AEROSPORES

S p o r e s a r e m i n u t e u n i c e l l u l a r or m u l t i c e l l u l a r

r e p r o d u c t i v e b o d i e s or ce l l s a d a p t e d t o s u r v i v e i n

u n f a v o u r a b l e e n v i r o n m e n t a 1 c o n d i t i o n s I n P a l a e o - o r

~ e o - p a l y n o l o g y , t h e y a r e s e e n a s h a p l o i d , d i s p e r s e d

r e p r o d u c t i v e b o d i e s o f e m b r o p h y t i c p l a n t s , h a v i n g a

i v e r y r e s i s t a n t o u t e r w a l l ( e x i n e l , and f r e q u e n t l y I

o c c u r r i n g a s f o s s i l s f r o m S i l u r i a n t o H o l o c e n e

(Traverse , 1986).

A t m a t u r i t y , t h e spores a r e r e l e a s e d i n t o t h e

a t m o s p h e r e b y t h e a c t i o n of wind or o t h e r meteorolo-

g i c a l f a c t o r s . T h e s p o r e c o n c e n t r a t i o n s m e a s u r e d i n

t h e a t m o s p h e r e a r e t h e r e s u l t o f a w i d e r a n g e o f

c o m p l e x l y i n t e r r e l a t e d e n v i r o n m e n t a 1 and b i o l o g i c a l

v a r i a b l e s (Lyon et a l , 1 9 8 4 ) . T h e c o n c e n t r a t l o n o f

f u n g a l s p o r e s and p o l l e n i n t h e a t m o s p h e r e a r e

i n f l u e n c e d b y p r o d u c t i o n , r e l e a s e and d e p o s i t i o n .

D i r e c t l y r e l a t e d t o t h e s e i s p r e c i p i t a t i o n w h i c h i s

c r i t i c a l i n t h e g r o w t h o f f u n g i a n d p l a n t s , and

a f f e c t e - t h e amount and t i m l n g o f . p r o d u c t i o n o f s p o r e s ,

( R o y e s , 1 9 8 7 ; Lyon et a l , 1 9 8 4 ) . R a i n f a l l h a s a l s o

b e e n shown t o a f f e c t t h e n u m b e r s of s p o r e s r e l e a s e d

f o r t h e m a j o r i t y o f f u n g i s t u d i e d b y R o y e s (19871,

H e f o u n d t h e r e l e a s e of some f u n g a l s p o r e t y p e s c o i n c i d e n t

w i t h f a l l i n g r a i n , s u g g e s t i n g t h a t t h e s e s p o r e s were

r e l e a s e d b y t h e m e c h a n i c a l e f f e c t . o f r a i n .

Wind h a s b e e n a t t e s t e d a s a v e r y i m p o r t a n t a n d

i n d i s p e n s a b l e f a c t o r i n s p o r q d i s c h a r g e a n d d i s p e r s a l .

Wagganer ( 1 9 7 3 ) , f o u n d t h a t w i n d o f 3m/sec f o r 1 5

s e c o n d s o n a s t a t i o n a r y l e a f w o u l d r e m o v e 20% o* t h e

spores of H e l m i n t h o s p o r i u m m a y d i s . W h i l e A y l o r a n d

t u k e n (19741, f o u n d t h a t i n t h e course o f o v e r several

lwurs i n t h e morning, wind of 1.0 nr/sc s p e e d , r e l e a s e d

60-75% of t h e s p a r e o f t h e same s p e c i e s w h e t h e r t h e

l e a f was s t a t i o n a r y or s w a y i n g . However , L y o n , e t a1

(1984), e s t a b l i s h e d t h a t t h e s p o r e c o n t e n t of t h e

a t m o s p h e r e w a s d i r e c t l y c o r r e l a t e d w i t h h i g h e r minimum

w i n d v e l o c i t i e s , b u t i n c o n t r a s t h e f o u n d t h a t maximum

w i n d s t h a t a p p r o a c h t h e u p p e r l i m i t s o f t h e r a n g e o f

v e l o c i t i e s were c o r r e l a t e d w i t h d e c r e a s e i n s p o r e

n u m b e r s i n t h e a t m o s p h e r e a t a l o w e r h e i g h t . his w a s

t r a c e d t o h i g h e r w i n d w h i c h r e m o v e s p o r e s m o r e r a p i d l y

a n d create a s h a r p p e a k i n s p o r e c o n c e n t r a t i o n s i n t h e

a k m o s p h e r e . C o n s e q u e n t l y , t h e s h a r p p e a k s p o r e

c o n c e n t r a t i o n s d e c r e a s e d t o l e v e l s b e l o w t h o s e

m a i n t a i n e d f o r l o n g e r times w i t h l o w e r maximum wind b

v e l o c i t i e s .

A c c o r d i n g t o R o y e s ( 1 9 8 7 1 , s e a s o n a l p e r i o d i c i t y

( w e t a n d d r y p e r i o d s ) and i t s a t t e n d a n t f a c t o r s w a s

f o u n d t o a f f e c t t h e maximum and minimum number of s p o r e

t y p e s r e l e a s e d w i t h i n a q i v e n p e r i o d .

However , P r i n c e arid Meyer ( 1 3 7 6 1 , r e p o r t e d t h a t

h m l d l t y and t e m p e r a t u r e p r o b a b l y werc-. t h e ~riost i m p o r t ant

f a c t o r s i n v o l v e d i n t h e r e l e a s e and d l s p e r s a l o f a i r s p o r a .

S l r r e t and tiarrrburq?>r, ( 1 9 7 6 1 , h o w e v e r , l o u n d a n i n v e r s e

ra l at1 o n s h i p b e t w e e n a i r s p o r a c o u n t s and mean t e m p e r a t u r e ,

dew polntr. dnd h u m i d i t y .

't'hc h r i r j h t of tl\e s a m p l i n q u n i t c:ould be associated

w i tli t h e q u a n t i t y and q u a 1 i t y of a e r o s p o r a t r a p p e d .

k h n n d e ~ l w d l ( 19881, suqgesks t h a t t h e d i f f e r e n c e i n

c o m p o s i t i o n of a e r o s p o r a a t d i f fe rer~t h e i g h t s may b e

l l n k e t l t o m c . t e o r o l w ~ i c - a 1 f a c t o r s a s s o c i a t e d w i t h s o u r c e ,

s a m p l i n g u n i t and t h e d i v e r s i t y i n s i z e of f u n g a l s p o r e s ,

t i m i n g , d u r a t i o n and m a g n i t u d e d f s p o r e d i s p e r s a l form,

N u m e r i c a l l y , f u n g a l s p o r e s h a v e b e e n f.ound t o b e

d o m i n a n t members o f t h e a i r b o r n e p a l y n o m o r p h s , Of t h e

c a n p o s i t i o n , t h e p r o m i n e n t c o n s t i t u e n t s a r e t h o s e o f

C l a d o s p o r i u m , U s t i l a q o , H e l m i n t h o s p o r i ~ , D i a t r y p s ,

S p o r o b o l o m y c e t a c e a e q r o u n , Glomerel l a , h y a l i n e and

c o l c h r e d b a s i d i o s p o r e s , and s e p t a t e f u s i f orm s p o r e s ,

( R o y e s , 1987)-

11.

S t u d i e s o f a i r s p o r a h a s l e d t o t h e a s s e r t i o n

t h a t f u n g a l s p o r e s a p p e a r u b i q u i t u o u s a n d t h e i r

c o n c e n t r a t i o n i n a i r t e n d t o v a r y i r r e s p e c t i v e o f

t i m e a n d s e a s o n . A c c o r d i n g t o G r e g o r y ( 1 9 7 3 ) , . t h e

f u n g a l s p o r e s d o n o t p r e s e n t d e f i n e d s e a s o n a l

p r e v a l e n c e p a t t e r n s a n d o f t e n a r e d i s t r i b u t e d i n a

c o s m o p o l i t a n f a s h i o n t h a t d o e s n o t a l l o w g e o g r a p h i c

d i s c r i m i n a t i o n .

he s t u d y of a e r o b i o l o q y is c u r r e n t l y u s e d f o r :

i. p r e d i c t i n g t h e s p r e a d o f a i r b o r n e p l a n t a n d

a n i m a l d i s e a s e s ;

ii. f o r i d e n t i f y i n g i n s e c t s a n d o t h e r a i r b o n e

m i n u t e o r g a n i s m s u s e d f o r v a r i o u s s c i e n t i f i c

a n d p r a c t i c a l p u r p o s e s , a n d

iii. f o r e c a s t i n g t h e p a t t e r n o f s p r e a d of

a l l e r g i c p a r t i c l e s .

I n M i n n e s o t a , s p o r e t r a p p i n g h a s b e e n u s e d f o r 2 0

y e a r s , f o r f o r e c a s t i n g t h e a d v e n t of w h e a t stem r u s t .

A l s o i n s o u t h A m e r i c a , s p o r e t r a p p i n g i s a n a i d i n

p r e d i c t i n g o u t b r e a k s o f " ~ i t r u s b l a c k s p o t w . he

b l i s te r b l i g h t of t ea c a u s e d b y ~ x o b a s i d i u m n e x a n s

was d i s c o v e r e d o n i t s a p p e a r a n c e i n I n d i a a n d C y l o n b

i n 1 9 4 9 a f t e r e x i s t i n g i n Assam s i n c e 1868

2 . 3 P O L L E N G R A l N S

T h e k n o w l e d g e arld u n d e r s t a n d i n q of p o l l e n r e l e a s e

a r e r e l e v a n t t o the s t u d y of' p o l l i n a t i o n e c o l o g y a n d i n

d e v e l o p i n g a f u n c t i o n a l m o d e l f o r f o r e c a s t i n g p o l l e n

c o n c e n t r a t i o n s i n t h e a t m o s p h e r e (Lyon al, 3 9 8 4 ;

I t e d d i a n d R e d d i , 1985; A n d e r s e n , 1380). P o l l e n r e l e a s e

t1nr-J t o c7 q r e a t ~ r e x t e n t t h e i r d i s p e r s a l , a re i n f l u ~ n c e d

h y t:he time of d a y (RerJdi and R p C d i , 1485). The

: J r.itc cf Ltlcr t l l s c t ~ a r y o r l po l l c -11 cjr-in:; i n t h e

arnbienk of.mo..;;~hrare d e p e n d s on t h r e x t e n t a f a i r

m o v e m e n t and/or- k l i ~ . r n a q r l i t u d ~ o f a t m o s p h e r i c t u r b u l e n c e ,

w h i c h v a r y a c c o r d i n q t c v a r i a f i o n s i n a i r temperakcre

t h r c u q t i o u t t h e d a y , ( R e d d i and Reddi, ,1985).

E v i d e c c e f r c m , p a s t s t u d i e s h a v ~ shown t h a t t h e r e

i s s i g n i f i c a n t variations i n t h e f r e q u e n c y o f p o l l e n

g r a i n s i n t h e a i r f r o m y e a r t o y c a r ( A n d e r s e n , 1980;

L e w i s , 1986; S p i e k s m a , et al, 1985). T h e c a u s e w a s

a t t r i b u t e d h i g h l y t o v a r i a t i o n i n f l o w e r i n g i n t e n s i t y

a n d p o l l e n p r c l d u c t i v i t y d u e t o c l i r n a t i c v a r i a t i . o n s

( ~ n d e r s e n , 1980). I n c o r o b o r r a t i o n , A n d e r s e n ( 1974)

f o u n d v a r i a t i o n i n a m o u n t s o f p o l l e n d e p o s i t e d

a n n u a l l y i n a m i x e d d e c i d u o u s f o r e s t w i t h i n a s i x y e a r b

s a m p l i n g p e r i o d a n d a t t r i b u t e d t h i s t o v a r i a t i o n j n

13.

p o l l e n p r o d u c t i v i t y . A l s o , ringf felt e t a 1 ( 1 9 8 2 ) A-

a n d C h e n , ( 1 9 8 4 ) i n s e p a r a t e s t u d i e s e s t a b l i s h e d

t h a t p o l l e n q u a n t i t i e s a n d t h e p o l l i n a t i o n p e r i o d

c a n d i f f e r f r o m o n e y e a r t o a n o t h e r o w i n g t o c h a n g e s

i n w e a t h e r f a c t o r s , a n d p h e n o l o g i c a l c o n d i t i o n s o f

t h e p l a n t s t h e m s e l v e s .

P o l l e n re lease i s a p h e ~ i o m e n o n w h i c h o c c u r s a t

a n y g i v e n t i m e o f t h e d a y a n d n i g h t . H o w e v e r , t h e

i n t . e r ~ s i t y a n d f r e q u p r l c y o f t - h i s release a p p e a r s morc

p r a m i n e n t a t c e r t a i n p e r i o d s . ACLOL-ding t o n r i n g f e l t .

e t a1 (1982), m o s t p o l l e n a r e d i s p e r s e d d u r i n g t h e -- d a y b e c a u s e t h e t u r b u l e n t m i x i n g of a i r i s more

e f f e c t i v e d u r i n g t h i s p e r i o d . I n a n o t h e r r e s e a r c h

w o r k , ~ p i e k s m a e t a1 ( 1 9 8 5 ) f o u n d t h a t t h e d a i l y p o l l e n -- c o u n t w a s g e n e r a l l y h i g h o n d a y s w i t h o u t much r a i n a n d

a t r e l a t i v e l y h i g h t e m p e r a t u r e . S p e c i f i c a l l y , t h e y

p o i n t e d o u t t h a t t h e b e g i n n i n g of g r a s s p o l l e n s e a s o n

seems t o b e t r i g g e r e d o f f b y a r i s e i n t e m p e r a t u r e .

C o n s i d e r a b l y , m o s t a i r b o r n e p o l l e n a r e

a n e m o p h i l o u s a n d t h e i r b o u y a n c y i s e n h a n c e d b y s m o o t h

w a l l ( e . g . g r a s s e s ) a n d t h e i r g e n e r a l l y s m a l l s i z e

a n d g o o d a e r o d y n a m i c p r o p e r t i e s ( L e w i s , 1 9 8 2 ; ~ g w u b

a n d ~ s i b e , 1 9 9 2 ) . T h e s l i g h t e s t breeze w o u l d d i s l o d g e

, a n d d i s p e r s e t h e p o l l e n . I n c o n t r a s t , t h e

e n t o m o p " h i 1 o u s p o l l e n a r e more r o u g h - w a l l e d a n d l a r g e r ,

a n d are h e l d t o g e t h e r b y more c o h e s i v e f o r c e s ,

c o n s e q u e n t l y , t h e y r e q u i r e s t r o n g e r w i n d t o d i s p e r s e

t h e m ( S u b a - R e d d i - e t -9 a1 1 9 8 0 b ) .

G r e g o r y (1973), b a s i n g o n t h e k n o w l e d g e o f

a e r o d y n a m i c s o f p a r t i c l e t r a n s p o r t a n d c a p t u r e

e s t a b l i s h e d t h a t t h e e x t e r l t o f d i s p e r s a l was

c o n t r o l l e d b y a n i n t e r a c t i o n of t h e t e r m i n a l v e l o c i t y

of tile p o l l e n a n d w i n d v e l o c i t y , a n d t h a t t h e a c t u a l

c o n c e n t r d t i o n s o f p o l l e n i n t h e a k r n o s p h e r e a t a n y p o i n t

downwind of t h e s o u r c e were i n f l u e n c e d b y e d d y i n g o f

t h e a t m o s p h e r e , In f u r t h e r a n c e of t h e a e r o - p r o p e r t i e s *

o f p o l l e n , L e w i s (1986), o p i n e d e m p h a t i c a l l y t h a t m o s t

a i r b o r n e p o l l e n are n e a r o r r o u g h l y s p h e r o i d a l w i t h

f e w e x c r e s c e n c e s ' s or s p i n e s , l i m i t e d s u p e r f i c i a l

p o l l e n - k i t t , t h e r e b y r e d u c e d i n s t i c k i n e s s , a n d

g e n e r a l l y d r i e r .

P o l l e n release a n d t o a g r e a t e r e x t e n t d i s p e r s a l

was c o r r e l a t e d t o d a i l y p a t t e r n s o f t e m p e r a t u r e , a i r

c u r r e n t s , r e l a t i v e h u m i d i t y a n d e l e c t ro s t a t i c

c o n d i t i o n s ( s p i e k s m a , - e t -9 a 1 1985) . E l e c t r o s t a t i c a l l y ,

p o l l e n o n s h e d d i n g h a s a weak n e g a t i v e c h a r g e , b u t

. s u b s e q u e n t l y a c q u i r e s a s t r o n g p o s i t i v e c h a r g e a s

g r a i n s a r e p a s s i v e l y c a r r i e d b y w i n d . his p r o p e r t y

h e l p s i n t h e d i s p e r s a l a n d c a p t u r e o f p o l l e n b y

a n e m o p h i l o u s p l a n t s .

A p a r t f r o m t h e e f f e c t o f m e t e o r o l o g i c a l f a c t o r s ,

t h e c o n c e n t r a t i o n o f a t m o s p h e r i c p o l l e n c o n t e n t w a s

c o n s i d e r e d g r e a t l y a f f e c t e d b y t h e g e o g r a p h i c a l

d i s t r i b u t i o n of t h e p o l l e n p r o d u c e r s a n d t h e p e r j o d of

m a i n p o l l e n r e l e a s e ( c a l l e j a - e t - 9 a 1 1993), c o u p l e d

w i t h t h e q u a l i t y of p o l l e n t y p e s to be c a p t u r e d .

2-4 POLLEN AND SPORE ALLERGY

An a l l e r g y r e a c t i o n i s t h e t e n d e n c y o f t h e b o d y

t o react a d v e r s e l y t o s u b s t a n c e s t h a t a r e u s u a l l y f r o m

o u t s i d e t h e b o d y a n d t h e y a r e t y p i c a l l y p r o t e i n s . T h e

p r o t e i n s t h a t c o u l d c a u s e a l l e r g y u s u a l l y come f r o m

e n v i r o n m e n t a l p a r t i c l e s s u c h a s p o l l e n , s p o r e s , d u s t

a n d o t h e r m i c r o - o r g a n i s m s t h a t may e n t e r t h e b o d y

t h r o u g h t h e n o s e o r e y e s ( ~ e w E n c y c l o p a e d i a B r i t a n i c a ,

1 9 8 0 ; ~ u r c h f i e l d , 1 9 9 1 ) . he p r o t e i n c o n t e n t o f t h e s e

mate r ia l s o n c o n t a c t w i t h t h e b o d y e l i c i t s a s e n s i t i -

z a t i o n w h i c h c a u s e s t h e a d v e r s e r e a c t i o n . his p r o t e i n

i s c a l l e d a n t i g e n ( a l l e r g e n ) a n d c a u s e s t h e f o r m a t i o n

o f a r ~ t i b o d i e s ( g l o b u l i n ) .

b T h e i n h a l a t i o n o f t h e s e a n t i g e n s ( s p o r e s o f

f u n g i , p o l l e n g r a i n s , a n d o t h e r a i r b o r n e a l l e r g e n s )

16.

i s now w i d e l y a c c e p t e d a s o n e o f t h e i m p o r t a n t c a u s e s

o f h a y f e v e r ( P o l l i n o s i s ) a n d a l l e r g i c a s t h m a . T h e

e x u d a t e s a n d e x t r a c t s o f t h e s e a l l e r g e n s a l s o c a u s e

s k i n or w h o l e b o d y r e a c t i o n ( ~ e w E n c y c l o p a e d i a 1 3 r i t a n i c a ,

1 9 8 0 ; V i t t a l a n d G l o r y , 1 9 8 5 ; R o y e s , 1 9 8 7 ) .

2.4.1 HAY FEVER A N D ALLERGIC ASTHMA

~ h e s e a i l m e n t s are c h a r a c t e r i z e d b y r e c u r r e n t ,

u s u a l l y s e a s o n a l r h i n i s t i e s ( r u n n y - s t u f f y n o s e ) w i t h

s w e l l i r ~ y of t h e mucous m e n r h r a r ~ e s of the n o s e , i t c h i r ~ q

of t h e eyes a n d n o s e , s n e e z i n g a n d c o u q h ( ~ e w ~ n c y c l o -

p a e d i a 8 r i t a n i c a , 1 9 8 0 ) . I n h a l e d p a r t i c l e s o f p o l l e n ,

a n i m a l d a n d e r or d u s t are t h e u s u a l c a u s e s , a n d t h e

s e v e r i t y of e f f e c t s o n s u s c e p t i b l e p e r s o n . is

p r o p o r t i o n a l t o t h e q u a n t i t y o f t h e a n t i g e n i n h a l e d .

T h e i r e x t r a c t s a l s o c a u s e s k i n r e a c t i o n ( B u r g e , 1 9 8 5 ;

~ u r c h f i e l d , 1 9 9 1 ) .

T h e d i r e c t c a u s e o f t h i s a l l e r g y i s h i s t a m i n e

g i v e n o f f by t h e w h i t e b l o o d c e l l s i n t h e p r e s e r ~ c e o f

a n t i g e n a n d a n t i b o d y , a n d t h e t e n d e n c y t o s u f f e r h a y

f e v e r ( P o l l i n o s i s ) a n d a l l e r g i c a s t h m a i s i n h e r i t e d

(New ~ n c y c l o p a e d i a ~ r i t a n i c a , 1 9 8 0 ) .

P o l l i n o s i s i s known t o a f f e c t a n e s t i m a t e d 1 0 %

o f t h e p o p u l a t i o n o f t h e U n i t e d S t a t e s a n d i t s e f f e c t s

c o u l d be c o m p a r e d w i t h t h e d i r e c t e f f e c t s of a l l forms

of a i r p o l l u t i o n ( B e n n i n q h o f f , 1 9 7 3 ) . I n t h e

N e t h e r l a n d s , a b o u t 1.5% ( 2 0 0 , 0 0 0 ) of t h e p o p u l a t i o n

a r e h a y f e v e r a f f l i c t e d p a t i e n t s a n d t h i s h a s a r o u s e d

much r e n e w e d a1 l e r g o l o q i c a l a n d a e r o b i o l o q i c a l a t t e n t i o n

s i n c e 1969 ( ~ p i e k s m a , 1 9 8 5 ) .

A g r e a t n u m b e r of p o l l e n t y p e s s u c h a s A c a c i a ,

A l b i z i a , I - l i b i s c u s r o s a - s i n e n s i s , A m a r a n t h u s , C h e n o p o d i u m , - C y p r - r i ~ s , and many n t h r r s a r e a q e n t s of h a y f e v e r a t

t h ~ i r v a r i o u s flowcrinq seasons ( S p i e k s m a , 1985;

D r i n g f e l t , 298?). Some g r a s s p o l l e n s u c h as Aqrostis,

Anttrephora a n d c e r e a l s ( ~ e a - m a y s a n d P e n n i s e t u m ) h a v e

b c ~ n i d e n t i f i e d d s i m p o r t a n t i n h a l c n t : ~ r e s p o n s i b l e

f o r t h e e s c a l a t i o n of' r e s p i r a t o r y a 1 l e r g i c d i s o r d e r s .

H e n c e , t h e knowledqc? o f t h e f r e q u e n c y a n d s e a s o n a l

p e r i o d i c i t y of' t h e s e p o l l e n g r a i n s in t h e a i r i s

~ s s a n t i a l f o r e f f e c t i v e d i a g n o s i s a n d t h e r a p y o f t h e i r

a l l e r g i c r e a c t i o n s o n p a t i e n t s .

T h e q u a n t i t y o f a p o l l e n t y p e or g r o u p of p o l l e n

t y p c s r e q u i r e d t c p r o v o k e a n a t t a c k of h a y f e v e r ,

d ~ p b n d s l a r g e l y o n t h e n a t u r e of t h e p o l l e n g r a i n s a n d

t-hn s u s c e p t i b i l i t y or s e n s i t i v i t y o f t h e i n d i v i d u a l s .

TIIF! more s e n s i t i v e % h e i n d i v i d u a l i s to a l l e r g y t h e 6

lesser t h e q u a n t i t y o f p o l l e n r e q u i r e d t o p r o v o k e

a l l e r g y a n d v i c e v e r s a .

~ i k e t h e p o l l e n g r a i n s , f u n g a l s p o r e s a r e a l s o

known c a u s e s o f a l l e r g y . They may c o n t a i n o r e x u d e

solne c h e m i c a l s u b s t a n c e s ( p r o b a b l y p r o t e i n ) t o w h i c h

t h e b o d y r e a c t s a b n o r m a l l y . R o y e s ( 1 9 8 7 ) , s u g g e s t e d

t h a t a l l a i r b o r n e s p o r e s a r e p o t e r l t i a l l y a l l e r g i c ,

t h o u g h their a l l e r q e n i c i t y may n o t be r e l a t ed t o t h e i r

s i z e .

Some f u n g i have b e e n c o n f i r m e d t o s t i m u l a t e

slit-cific a n t i b o d y r ~ r u d u c t i o n . A h i g h l e v e l of

A s p e r q i l l u s - s p e c i f i c a n t i b o d i e s h a v e been r e p o r t e d

i r r p a t i e n t s w i t h a l l e r g i c b r o n c h o p u l m o n a r y a s p e r g i l l o s i s ,

w h i l e m o s t human sera c o n t a i n a t l e a s t some f u n g a l -

s p e c i f i c immunoglobulin-G ( I ~ G ) ( B u s h - et -' a 1 1 9 8 2 ) .

A l s o a w i d e v a r i e t y o f f u n g a l s p o r e s h a v e b e e n shown

t o e l i c i t i m m e d i a t e w h e a l a n d f l a r e s k i n r e a c t i v i t y i n

s u s c e p t i b l e i n d i v i d u a l s ( B u r g e , 1 9 8 5 ) .

~ a s i d i o s p o r e s a r e a n t i g e n i c a n d c a n e l i c i t

i m m e d i a t e s k i n r e a c t i v i t y i n s e n s i t i v e p a t i e n t s ( B u r y e ,

1985 ) . Moreso, i t i s now g e n e r a l l y a c c e p t e d t h a t mould

a r e q comrnor~ ' a e r o a l l e r g e r i o f humans . T h e a l l e r g e n i c i t y

o f A l t e r n a r i a i s a t t r i b u t e d t o i t s s p o r e s a n d n o t

m y c e l i a . T h e s p o r e s i n d u c e a s t h m a , w h i l e t h e i r e x t r a c t s

a r e > f f e c t i v e i n d u c e r s o f b r o n c h o p r o v o c a t i o n ( ~ u d d ,

1 9 8 6 ) .

1 9

T h e d i a g n o s i s a n d t r e a t m e n t of many a l l e r g i c

r e s p i r a t o r y d i s e a s e s s u c h a s a l l e r g i c a s t h m a a n d h a y

f e v e r ( P o l l i n o s i s ) a r e b a s e d on s k i n a n d l a b o r a t o r y '

t e s t s p c r f o r r n e d wit .h p o l l e n a n d s p o r e extracts. L

A l l e r y i c t a b l e t s of p o l l e n h a v e b e e n s u c c e s s f u l l y

p r o d u c e d in some a r e a s ( T r a v e r s e , 1 9 8 6 ) . A n t i h i s t a-

m i n e s , a d r e n a l h o r m o n ~ a n d d e s e n s i t i z a t i o n w i t h t h e

a n t i q e r ~ art> u s e d t o c u r e t h e attacks.

To a ~ ~ p r r c i a t e thc: s i q n i f i c a n c c of pol 1 e n and

S t u d i e s o f f o s s i l p o l l e n and s p o r e s i n sed i rncr l? s

h 4 v e c o n t r i b u t e d .in t h e i n t e r p r e t a t i o n of Q u a t e r n a r y

p o l l e n s e q u e n c e . I t h a s h e l p e d i n the t l n d e r s t a n d i n q of

t i ) :> v e q ~ t i ~ t . i o n and cl lrnat i c h i s t o r y of rnany r e g i o n s .

A c c o r d i n g t o Moore and Webb, ( 1 9 7 8 1 , t h e a b u n d a n c e with

w h i c h t h e s e p o l l e n a n d s p o r e s o c c u r i n rnany s e d i m e n t s

rnakcs tihem u s e f u l f e a t u r e s f o r q u a 1 i t a t i v e a n d q u a n t i t a t i v e

a n a l y s i s . Moreso, s t u d i e s o f p o l l e n r e c o r d s r e f l e c t i n g

v c l q c ? k a t i o n a l c h a n q e s i n time h a v e b e e n Found t o be an b

i m p o r t a n t b a s l s f o r t h e c l i m a t i c h i s t o r y o f many

20.

c o n t i n e n t a l a r e a s (Agwu a n d B e u g , 1 9 8 2 ; Dupont a n d

Agwu, 1 9 9 1 ; t l o o g h i e m s t r a - e t - 9 a 1 1 9 9 2 ; D u p o n t , 1 9 9 3 ;

L e r o y a n d D u p o n t , 1 9 9 4 ) .

F o s s i l p o l l e n a n d spo;e a s s e m b l a g e s a c c o r d i n g t o

Sowunmi ( 1 9 9 1 ) , o f f e r b e t t e r r e f l e c t i o n o f a d j e c e n t

a n d e v e n r e g i o n a l v e g e t a t i o n s s i n c e t l l ey o r i g i n a t e

f r o m v a r y i n g d i s t a n c e s a s w e l l a s n e i g h b o u r i n g

l o c a l i t i e s . s i m i l a r l y , t h e v e g e t a t i o n of a n y a r e a i s

i l r l i r r t e g r a l c o m i m ~ l c r ~ t o f t tic c !co : ;ys k e r n a n d i s

s e n s i t i v e t o a n y c h a n g e s i n t h e e s t a b l i s h e d

h o m e o s t a t i c s or e q u i l i b r u m . C o n s e q u e n t l y , v e g e t a t i o n

c h a n g e s c a n t i ~ e r n s e l v e s be s a i d t o be a r e s p o n s e t o

a n d a r e f l e c t i o n o f v a r i a t i o n s o f e n v i r o n m e n t a l

f a c t o r s ( ~ o w u n m i , 1 9 8 6 ) . T h e p o l l e n a n d s p o r e s o f

s u c h v e g e t a t i o n when f o s s i l i s e d , c o n s t i t u t e i n d e l i b l e

a n t i q u e i n t h e r e c o n s t r u c t i o n p r o c e s s .

I n t r a c i n g t h e h i s t o r y a n d d e v e l o p m e n t o f

v e g e t a t i o n i n t i m e , p o l l e n a s s e n i b l a g e s o r i g i n a t i n g

f r o m t h e l o c a l e n v i r o n m e n t o f t h e core s i t e a r e

c o n s i d e r e d more s u i t a b l e a s i n d i c a t o r s o f e n v i . r o n m e n t a 1

c o n d i t i o n s i n t h e a r e a ( H a m i l t o n , 1 9 7 6 ; G u p t a , 1 9 9 0 ;

Sowunmi, 1 9 9 1 ) . M o r e s o , p o l l e n t y p e s a r e g r o u p e d b

i n k o v e g e t a t i o n z o n e s o f p h y t o e c o l o g i c a l u n i t s b a s e d

o n t h e p r e s e n t d a y g e o g r a p h i c a l d i s t r i b u t i o n s ( ~ o o t h ,

1 9 5 7 ; H a m i l t o n , 1 9 7 6 ; Sowunmi, l 9 9 l ) .

A l t h o u g h , f o s s i l p o l l e n a n d s p o r e s d o n o t

p r o v i d e a n e x a c t p i c t u r e of t h e c o n t e m p o r a r y

v e g e t a t i o n i n terms of b o t h s p e c i e s c o m p o s i t i o n a n d

d i s t r i b u t i o n , t h e y s t i l l c o n s t i t u t e some of t h e best

known d i r e c t i n d i c a t o r s of p a s t e n v i r o n m e n t s

( Sowunmi, 1 9 9 1 ) . The d i f f e r e n t i a l p r o d u c t i o n ,

d i s p e r s i o n and p r e s e r v a t i o n o f p o l l e n g r a i n s and

~ ~ ; j o r c s h a v e q i v e n r i se t o the u n d e r r e p r e s e n k a t i o n

i n t h e pollen assemblages, t h u s limiting t h e

c o n v e n t i o n a l m e t h o d of e v a l u a t i o n and r e c o n s t r u c t i o n

of palaeof lo r i s t i c models-

I n West A f r i c a , n u m e r o u s p a l y n o l q i c a l w o r k s

h a v e b e e n c a r r i e d o u t on d e e p s e a s e d i m e n t s ( ~ g w u and

R e u g , 1 9 8 2 ; H o o g h i e m s t r a , 1 9 8 8 ; Dupon t and Agwu, 1 9 9 1 ;

t i o o g h i e m s t r a , & al, 1 9 9 2 ; D u p o n t , 1 3 9 3 . A l a r q e

i n t e r p r e t a t i o n o f l a t e Q u a t e r n a r y v e g e t a t i o n

e n v i r o n m e n t a l c h a n g e s . T h e r e s u l t s o b t a i n e d

i n ' d i c a t e t h a t t h e v e g e t a t i o n of t r o p i c a l A f r i c a seems

t o h a v e r e t a i n e d i t s b a s i c s p e c i e : ; c o m p o s i t , i o n . T h i s

w a s r e v e a l e d b y macro-and m i c r o b o t a n i c a l e v i d e n c e b

f r o m v a r i o u s p a r t s o f Cameroon , Ghana , N i g e r i a

- ( N i c h o l s o n , 1 9 7 9 ; Sowunmi, 1381; M a l e y , l 9 8 9 ) , S e n e q a l ,

22.

T o q o ( L e z i n e arid E d o r h , 1 9 9 1 1 , C h a d , S a h a r a ( ~ e u m a n n , 1 9 9 1 ,

* 9 2 , ' 9 3 ; B r e u n i g , - - , et a1 1 9 9 3 ) a n d N-rJ - A f r i c a ( A g ~ u a n d

B e u q , 1 9 8 2 ; D u p o n t a n d Aqwu, 1 9 9 1 ; L e r o y a n d D u p o n t , I!" !,

etc. D u r i n q t h e E a r l y H o l o c e n e , p a l y n o l o q i c a l d a t a a l s o

s h o w n t h a t t h e r e w a s a g r e a t e x p a n s i o n of e v e r g r e e n f o r e s t s

i n t r o p i c a l West A f r i c a . D u p o n t and Agwu ( 1 9 9 1 ) , e s t a b l i s h e d

l a t i t u d i n a l e x t e n b i o n o f S a h e l , S a v a n n a s and d r y o p e n

fores t ( 2 0 9 1 0 ~ ~ ) a n d a n e x t e n s i o n o f wooded g r a s s l a n d s

0 a n d t : r a n s i t i ~ n a l f O t ' e s t ( lo0-o N ) b y means of grass

p o l l e n , a n d A l c h o r n e a a n d E l a e i s p o l l e n respectively,

i d ~ n t i f i ~ d a l o n g the G u l f of G u i n e a and o f f - s h o r e

N . W . ~ f r i c a . ~ c c o r d i n q t o D u p o n t ( 1 9 9 3 1 , b e f o r e

220ka Bp. i n N I W I A f r i c a , t h e t o p i c a l r a i n f o r e s t

p r o b a b l y e x i s t e d a s a z o n a l v e g e t a t i o n t h r o u g h d r y a n d

w e t p e r i o d s , b u t a f t e r 2 2 0 k a Bp. t h e t r o p i c a l r a i n f o r e s t

w a s r e d u c e d t o s c a t t e r e d o c c u r r e n c e s d u r i n g p e r i o d s w i t h

s e v e r e s t a r i d i t y .

A c c o r d i n g t o ( S o w u n m i , 19861, t h e v e q e t a t i o n i n t h e

N i q e r i a d e l t a w a s c h a r a c t e r i z e d b y f l u c t u a t i o n s i n

m a n g r o v e swamp as w e l l a s r e l a t i v e d u n i n a n c e of f o r e s t

v i s - a - v i s s a v a n n a . Agwu a n d Beuq ( 1 9 8 2 ) w o r k i n g o f f

tire c o a s t o f A f r i c a e s t a b l i s h e d t h a t t h e p r e s e n t

f o r e s t s a n d d e c i d u o u s trees was f o r m a l l y o c c u p i e d b

2 3

b y a s e m i - d e s e r t v e g e t a t i o n d u r i n g t h e ~ l a c i a l maximum

( a b o u t 1 9 , 0 0 0 BP t o 1 2 5 0 0 BPI. T h e s o u t h e r n b o u n d a r y

o f t h e S a h a r a a n d t h e a d j e c e n t s a v a n n a s w i t h g r a s s l a n d

a n d t r o p i c a l forest were s i t u a t e d more t o t h e S o u t h d u r i n g

t h e g l a c i a l p e r i o d s ( 1 9 , 0 0 0 BP t o 1 2 5 0 0 BPI t h a n t h e y w e r e

d u r i n q t h e i n t e r g l a c i a l o n e s ( 1 2 , 5 0 0 BP t o p r e s e n t ) .

The work of M a l e y (11989) i n Bosumtwi (Ghana) , showed t h a t

a t a b o u t 9 ,000-8500 t h e r e was s y n c h r o n i s m b e t w e e n m o n t a n e

v ~ q e t a t i o n ( 100M A$&) d i s a p p e a r a n c e and r a i n f o r e s t

reappearance, whl le i n O e r u n b i ~ b o ( w e s t e r n Cameroon 1 ,

p o l l e n d a t a i n d i c a t e d c l e a r l y t h a t f rom a b o u t 2 4 , 0 0 0 BP

r a i n forest p c r s i s t : e d w i t h l i m i t e d v a r i a t i o n s , t h u s

s h o w i n q a r e f u g i a a r e a .

C h a r c o a l f r o m p r e h i s t o r i c s i tes h a v e b e e n

c c m p l e m e n t a r i l y u s e d p a l y n o l o g y i n t h e r e c o n s t r u c t i o n

of p a s t v e g e t a t i o n a n d human i m p a c t on v e g e t a t i o n . D a t a

f r o m e a s t e r n S a h a r a ( ~ e u m a n n , 1 9 9 3 ) r e v e a l e d t h a t human

i m p a c t p l a y e d a major r o l e f o r t h e v e g e t a t i o n c h a n g e s

f r o m a b o u t 9 0 0 0 BP o n w a r d s . Neumann ( 1 9 9 1 ; 1993)

r e s u l t s showed a n o r t h w a r d s h i f t o f t r o p i c a l s a v a n n a s

a t l e a s t 500km a r o u n d 7 0 0 0 B P and an e x t e n s i o n o f

e a s t e r n S a h a r a , 300-400km a r o u n d 5700 BP.

. C o n s i d e r i n g t h e p a l y n o l o g i c a l a p p l i c a t i o n of

f o s s i l p o l l e n and s p o r e s i n v e g e t a t i o n r e c o n s t r u c t ipl,

s t u d i e s of r e c e n t d e p o s i t i o n s h a v e c o n t r i b u t e d i m m e n s e l y

i n t h e i n t e r p r e t a t i o n o f p o l l e n d i a g r a m s . However , t h e

p r e l u d e t o a correct i n t e r p r e t a t i o n o f f o s s i l p o l l e n d a t a

l i e s i n u n d e r s t a n d i n q of p o l l e n and s p o r e s and t h e i r

r e l a t i o n s h i p t o c l i m a t i c v e g e t a t i o n changes w h i c h

a c c o r d i n g t o L i v i n q s t o n e (1969) a r e i n t e r w o v e n and

v e r y d y n a m i c .

Most l a k e s , p e a t b o g s a n d c o a s t a l a r e a s a r e o l d

and t h e i r s e d i m e n t s c o n t a i n t h e m o s t d c ! t a i l e d g u i d e s

available t o t h e Q u a t e r n a r y v e g e t a t i o n and c l i m a t i c

h i s t o r y o f t h e r e g i o n s o f t h e i r l o c a t i o n s . T h e i r

r e l e v a n c e l i e s i n t h e f a c t t h a t many a c c i d e n t s of

d e p o s i t i o n p r e s e r v e p l a n t f o s s i l s i n a s t a t e s u i t a b l e

f o r t h e r e c o n s t r u c t i o n o f p a s t e n v i r o n m e n t s . A n y t h i n g

l i q h t e n o u g h t o be a i r - b o r n e may be e x p e c t e d r o u t i n e l y

as a f o s s i l i n s e d i m e n t s . P o l l e n g r a i n s , s p o r e s of

p t e r i d o p h y t e s a n d f u n g i , s p o n g e s p i c u l e s , d i a t o m s ,

(Jesrnids a n d o t h e r p a l y n c m o r p h s a r e p r e d o m i n a n t l y f o u n d

i n h u n d r e d s o f t h o u s a n d s t o m i l l i o n s f r o m a s m a l l s a m p l e

o f s e d i m e n t ( L i v i n q s t o n e , 1969).

T h e a d v a n t a q e s a t t a c h e d tc s e d i m e n t s i n w a t e r

are d u e t o t h e f a c t t h a t t h e cores are d e w o s i t e d i n

a s t r a t i g r a p h i c s e q u e n c e ( p r o f i l e ) (Moore and Webb,

1978). B a s i c a l l y , i t is a s s u m e d t h a t p o l l e n s p e c t r a

a t a n y g i v e n l e v e l ( s t r a t u m ) r e p r e s r : n t s t h e

c o n t e m p o r a r y p o l l e n p r d u c i n q f l o r a a$ t h a t qiver l

p t ? r i o d . I n w h i c h c a s e t h e i r r e l a t i v e a b u n d a n c e is

an i n d i c a t o r of the v e g e t a t i o n c h a r a c t e r i s t i c s a t

f t l , l t ~ ) r ~ r - i o d I n t ime. Morrso, p a l y n o m o r l ~ h s are bet:t.c?r

p r e s e r v d i n mud secl imm ts because of t h e s e d i m e n t

ctiernbstry.

N I q e r i a s e d i m e n t a r y b a s i n a n d i s u n d e r l a i n b y rocks

d a t e d w i t h i n t h e L a b e C r e t a c e o u s . T h e r o c k s a r e made

u p o f t h r e e f o r m a t i o n s : ( i ) t h e N s u k k a F o r m a t i o n

( U p p e r C o a l m e a s u r e s ) , ( i i ) Mamu F o r m a t i o n ( L o w e r C o a l

m e a s u r e s ) and ( i i i ) A j a l i S a n d s t o n e ( F a l s e - b e d d e d

ands stone) ( R e y m e n t , 1 9 6 5 ; Nwachukwu, 1 9 7 8 ) . T h e A j a l i

S a n d s t c n e i s p r e d o m i n a n t l y of s a n d y l i t h o l o q y w i t ti minor.

s h a l y p r e d o m i n a n t l y of s a n d y l i t h o l o g y w i t h m i n o r s h a l y

members . T h e Mamu F ' o r m a t l o n and Msuklca F u m a r s i o n a r e

p r e d o m i n a n t l y s h a l y w i t h m i n o r s a n d s t m e , s i l t s t o n e

and m u d s t o n e l a y e r s . T h e A j a l i F o r m a t i o n o v e r l i e s C

t h e Mamu f o r m a t i o n c w l f o r m a b l y , whi l e t h e Nsukka

f o r m a t i o n o v e r l i e s the Aj a l i S a n d s t one c o n f o r m a b l y .

T h e A j a l i S a n d s t m e t r e n d i n q i n n o r t h - s o u t h

d i r e c t i o n , i s bounded on t h e l e f t b y t h e Nsukka

F o r m a t i o n a n d on t h e r i g h t b y t h e Mamu F n r m a t i o n .

Surface waters a r e a b s e n t on t h e p e r m e a b l e members

of t h e A j a l l S a n d s t o n e , w h i l e l a k e s , streams and

f i v ~ r s , and m a . r s h l ; ~ n d s a r e h i q h 1 y d e v e l o p c v l on t r t i c

p o o r l y permeable, s h a l y Nsukka and Mamu F o r m a t i o n s

( E g b o k a , 1983).

N s u k k a a r e a h a s a h i q h c e n t r a l zme w h i c h l i es

q e n e r a l l y o v e r 365 metres a b o v e sea l e v e l , w i t h t h e

h i q h e s t known p o i n t l y i n g a t 590 metres a b o v e sea

l e v e l . T h e a r e a i s c h a r a c t e r i z e d by t w o t y p e s o f

l a n d f o r m s :

(a) r e s i d u a l h i l l s ; m d

(b) d r y v a l l e y s ,

These h i l l s and v a l l e y s , s u r f a c e w a t e r - bodies a n d

v e a e t a k i o n a r e related t o rock t y p e s o n q e o l o q i c

f o r m a t i o n s u n d e r l y i n g t h e a r e a s ,

T h e r e s i d u a l h i l l s a r e r e m n a n t s o f t h e N s u k k a

F'ormgtion t h a t c o v e r e d t h e e n t i r e a r e a d u r i n g the

C r e t a c e o u s p e r i o d . T h e r e s i d u a l h i 1 1 s w h i c h s a n e t i m e s

f o r m o u t l i e r s on t h e A j a l i S a n d s t o n e a r e s e p a r a t e d

b y t h e d r y v a l l e y s . T h e N s u k k a F o r m a t i o n and t h e

A j a l i S a n d s t o n e a r e c a p p e d b y t h i c k d e p o s i t s of r e d

e a r t h a n d l a t e r i t e s . T h e s e l a t e r i t e s a r e p e r m e a b l e

p a r t i c u l a r l y t h o s e on t h e A j a l i S a n d s t o n e , t h e r e b y

n l . l o w i n g easy w a t e r p e r c o l a t i o n i n t o t h e q r o u n d w a t e r

d u r i n g t h e r a i n y s e a s o n .

2 .R CLlMATE *

The c l i m a t e i s humid t rc tp jra l w l t h a n n u a l

temperature values v a r y i n g b e t w e e n 23.3O~ e n d

27.7O~. The c l i m a t e i s c h a r a c t e r i z e d b y t w o m a i n

s e a s o n s , t h e R a i n y seas- ( ~ p z i l t o S e p t e m b e r ) and

t h e d r y season (October t o M a r c h ) . T h e a n n u a l r a i n f a l l

f c l r N s u k k a town v a r i e s f r o m 9 8 6 m m t o 2,098.2mm. T h e

m a j o r w i n d s d u r i n g t h e r a i n y and d r y s e a s o n s a r e t h e

S o u t h w e s t and d r y N o r t h - e a s t t r a d e s r e s p e c t i v e l y .

B o t h w i n d s s y s t e m m e e t a l o n q t h e l i n e of I n t e r t r o p i c a l

D i s c c n t i n u i t y (I.T.D. w h e r e i t f l u c t u a t e s b e t w e e n

l a t i t u d e ON a n d t h e coast o f N i q e r i a ON d u r i n g t h e d r y

s e a s o n ( I n y a n q , 1978 1 , H a r m a t t a n w i n d s u s u a l l y d o m i n a t e

f r o m November t o J a n u a r y .

Lake O b a y i i s l o c a t e d on a p l a t e a u (549.6 m

a . s . 1 . ) w h i c h d r o p s o f f s h a r p l y on t h e e a s t f o r m i n q

a n e s c a r p m e n t b u t s l o p e s g r a d u a l l y t o the w e s t . The

l a k e i s s i t u a t e d i n a d e p r e s s i o n towards t h e w e s t e r n

e n d of t h i s p l a t e a u .

Beyond the e s c a r ~ m e n t t o t h e e a s t i n a d r y v a l l e y

i s located a relict, " s a c r e d f o r e s t M wIIJIcI~ o f f e r s

r a fuqch t o n u m p r o u s p l a n t s of- t rop lcg! ] . owland r a i n

f o r ~ s t s u c h os A f z a l i a a f r i c a n a , C e i b a p z t a n d r a , M i l l c l a

e x c e l s a ~ r i p l o c t i i t o n l a e v i s , Uapaca, ( ) l a x , g a e r t n e r a , ,-*----..' -- S c o t t e l i a and Faqara spp. T h r escarpment h o w e v e r , i s

p o p ~ l l a t e d by s a v a n n a qrass w i t h s c a t t e r e d trees made u p

m o z t l y of L o p h i r a - - l a n c e o l a t a , H y m e n o c a r d i a a e i d a , F a d o q i a , 7 -.

C i s s u s and B a p h l a p u b e s c e n s . The p l a t e a u i s a l s o p o p u l a t e d --- b y l a u d e t i a a n d scattered s t a n d s o f P r o t e q - , S y z y q i u m

g_u_ ineense , -- P a r i n a r i - c u r a t e l l i f o l i a a n d B r i d e l i a .

On t h e h i q h e r a rea o f t h e p l a t e a u t h e v e Q e t a t i o n i s an

open s a v a n n a of L o u d e t i a , H y p a r r h e n i a , ~ n d r o p o q o n , Penn i s e t u m ,

A n t h e p h o r a , P r o t e a , c y s s o n i a b a r t e r i a n d A s p a r a q u s . Farms - -.-- of v a r i o u s c r o p s e.9. C a j a n u s c a j a n , s l a n u r n , A b e l m u s c h u s ,

O r y z e a s a t i v a are m a i n t a i n e d .

w h i l e M a n q i f e r a - i n d i c a , G m e l i n a a r b o r e a a n d R a p h i a h a v e ---

been i n t r o d u c e d t o t h e s o u t h w e s t z o n e . M a t u r e trees.

a n d s a p 1 i n q s of B e r l i n l n g r a n d i f l ' o r a t o q e t h e r w i t h ----

C n e s t i s f e r r u q i n e a , ~ a p o l e o n b i m p e r i a l i s , C i s s u s - q u a d r a n q u l a r i s , Andropoqon , A l s t o n -- ia -- boonel, U v e r i a

chamea form an u n i n t e r r u p t e d t h i c k - t s cn t h e f r i n q e s of

k t i e l a k e .

Befare t h e v e q e t a t i m i n t h e l a k e was d e s t r o y e d

by f i r e d u r i n q t h e d r y season o f 1393/94, t h e r e was a

l u x u r i a n t q r w t h of t h e f o l l a w f n q p l a n t s : ~~~~~~~~~, t f y p a r r h e n i a , l a u d a t a , C l a p p e r t o n i a n a - f l l i c o i d e a ,

P o l y q a n u m , C y p e r u s , f e r n s a n d A l c h o r n e a c o r d i f 01 ia. - T h e v a l l e y on t h e w e s t and n o r t h - w e s t a r e

f . n h a h i t e d b y v i l l a g e s , f a r m s t e a d s and p l a n t s

a s s o c i a t e d w i t h aqro-f o r e s t r y . Most p r o m i n e n t among

t: h e s e are --- E l a e i s g u i n - e e n s i s , P a r k l a b i q l o b o s a ,

I r v i n q i a g o b o n e n s i s , C o l a n i t i d % , M i l i c i a e x c e l s a ,

T r e c u l i a a f r i c a n a and some i n t r o d u c e d f r u i t trees,

e x a m p l e : - Manqif e r a -. i n d i c a , Anacard ium - o c c i d e n t a l e ,

A z a d i r ' a c t a i n d i c a a n d C a r i c a p a p a y a . - T h e u n i v e r s i t y campus i s located i n a d r y v a l l e y

s u r r o u n d e d b y s e v e n c m i c a l h i l l s w i t h a d e r i v e d

s a v a n n a v e q e t a t i o n , I n t h e l a s t 35 y e a r s t h e n a t u r a l

v e g e t a t i o n h a s been d e s t r o y e d and r e p l a c e d by

i n t r o d u c e d a e s t h e t i c p l a n t s i n most: p l a c e s . T h e most

i m p a r t a n t of t h e s e a r e C a s u a r i n a e q u i s e t i f o l i a ,

M a n q i f e r a i n d i c a , P i n u s , C a s s i a , E u c a l y p t u s ,

A z a d i r a c a t a l n d i c a , Khaya i v o r e n s i s , G m e l i n a arboream

T e r m i n a l i a catappa- Some o f t h e l o c a l trees t h a t h a v e - b e e n p r o t e c t e d i n c l u d e M i l i c i a e x c e l s a , N a u c l e a d i d i r e c h i

and E l a e i s q u i ~ r e e n s i s .

I n t h e Uot:anI r-a1 Garden w h e r e ' onc of the

irt:maspheric pollen c a l l ~ c t o r s was l o c a t e d , a lo t mare

trees, s h r u b s a n d crops qrow t h e y e a r a l l r o u n d u n d e r

p r o t e c t i o n and care- These i n c l u d e : Af z e l i a - a f r i c a n a ,

C a s u a r i r i a e q u i s e t i f o l i a , T r e c u l ia a f r i c a n a , R a p h i a , - - -. E l a e l s q u i n e e n s i s , C h r y s o p h y l u m a l b i d u m , T e c t h l a --- q r a n d i s , ~ l b i z i a , C a n a n q a o r d o r a t a , E u p h o r b i a ,

R a u v o l f i a v u n i t o r i a , A m a r a n t h u s , V i q n a , M a n q i f e r a --- .

i n d i c a , L a u d o l p h i a o w e r i e n s i s and o t h e r C a e s a l p i n a c e a e

a n d P a p i l i o n a c e a e f a m i l i e s .

W i t h i n t h e v a l l e y s a r o u n d t h e U n i v e r s i t y and on

t h e h i l l s a r e t o be f o u n d r e 1 ict o f t h e n a t u r a l

v e q e t a t i o n , t h o u g h i n d e p l e t e d s t a t e .

CHAPTLR THREE

M A T C H l A L Y ANU' MLTHUC,

3 .3 SAMPLlNG TECHN l y U E

AGwU M6-5 a t m o s p h e r i c p o l l e n s a m p l e r w a s u s e d

f o r t h e s t u d y . T h e M6-5 s a m p l e r c o n s i s t s of a

c y l i n d r i c a l p l a s t j c c a s i n g 15x4cm w i t h about 8 4

o p e n i n q s (0.20Cm d i a m e t e r e a c h ) to e n h a n c e t h e f ree

f l o w of a i r . I t h a s a movable b a s e a f f i x e d t o the

main body b y m e a n s of t w o a d j u s t a b l e screws. T h r o u g h

l o a a l n a t h e screws, t h e b a s a l p a r t s l i d e s dawn and

e x p o s e s a 2.85x4.0cm o p e n i n q made a t the. o p p o s i t e s i d e s

of Fhc. main body. T h r o u g h these o p e n i n g s t h e p r i m e d

s l i d e Is I n s e r t e d , w i t h t h e sticky s u r f a c e f a c i n q

u p w a r d s , h e x t e r n a l h o o d was a t t a c h e d a t t h e u p p e r

e n d of t h e s a m p l e r t o p r o t e c t : i t f r c m r a i n d r o p s ,

A s a m p l e r was m o u n t e d on the f l a t r o o f of a t w o -

s t o r e y b u i l d i n q ( F a c u l t y of B i o l o q i c a l S c i e n c e s

b u i l d i n q ) a t a h e i g h t of a b o u t 1 5 metres a b o v e q r c u n d

l e v e l ( P l a t e 1) t o e n s u r e f ree a n d u n r e s t r i c t e d f l o w

of a i r . T h e s e c o n d s a m p l e r w a s s u s p e n d e d a t a h e i g h t

of a b o u t 1 .80 metres a b o v e a r o u n d l e v e l i n B o t a n i c a l

G a r d e n , T h e l o c a t i o n s o f t h e s a m p l e r s are a b o u t 1000m

b

a p a r t .

3 3 . I PREPARATION 0 F SLIDE --

A plece of t r a n ~ p n r e n t tape 3x3cm, cleaner1 with

RM-r)W? ethanol was by means of FI double f n c e d

nf!h.lnr ;:re tape wag a t f i x e d by means of ado!~blc faced

tayn on t o t h e centra l poe l t f on of R clenn microsca~e

f 3 J . i d ~ . T h e uppcr surfnce of the t l rnnspnrent tnpc w n R

nmeared w f t h n b m t 0,5g1n "WEJSSER" VASETITWE t hn t , r,ervt?R

R F I cn n r f h e ~ i v e layer . On of such p'rapnrcd ~ 3 1 r l e a wns

then ~nor~ntad i n each of the ~ a m p l c r o ruld t h e n exposed

for ori0 week,

A t t h e e n d of e v e r y s e v e n d a y s , t:he s l i d e s w e r e

r e c o v e r e d a n d the t r a n s p a r e n t t a p e b e a r i n g t h e t r a p p e d

p a l y n o m o r p h s was c a r e f u l l y d e t a c h e d w i t h t h e a i d of

a p ( 3 i r of f o r c e p t s and p l a c e d c e n t r a l l y on t o a f r e s h

c l e a n e d m i c r a s c o p e - s l i d e i n 0.2ml of q e v a t o l . About

O . % m l d r o p s of q e v a t o l was a q a i n p u t on t h e

p a l y n o m o r p h - h e a r i n g t a p e , and covered w i t h a c l e a n e d

l n r q e c o v e r s l i p ( 2 4 x 5 0 ) . T h e prepared sl i d e was

t h e n p l a c e d u p s i d e d m n t o rest on the c o v e r - s l i p i n

a s l i d e - t r a y , T h e w e i q h t of the s l i d e e n s u r e s an even

spread of q e v a t o l o v e r t h e e n t i r e p o l l l n i f e r o u s

mount. E a c h s l i d e w a s l e f t i n t h i s p o s i t i o n f o r 2

weeks t o a1 l o w t h e p a l y n o m o r p h s s e t t l e close t o t h e

c o v e r s l i p . C o u n t s w e r e made u s i n g a K Y W A b i n o c u l a r

m i s c r o s c o p e a t x 4 0 0 m a g n i f i c a t i o n and o c c a s i o n a l l y

u s i n q xlOOO m a g n i f i c a t i m . ( o i l immersion f o r closer

m o r p h o l o g i c a l e x a m i n a t i o n .

New p r i m e d s l i d e s w e r e e x p o s e d e v e r y week f o r o n e y e a r

( F e b r u a r y , 1993 t o J a n u a r y , 1 9 9 4 ) . A t o t a l o f 5 2

s 1 i d e . s w e r e e x p o s e d a t e a c h l o c a t i o n , m a k i n g a t o t a l

o f 1 0 4 slides u s e d f o r t h e w h b l e s t u d y .

l d e n t i f i c a t i on of p o l l e n and spcres were b a s e d

on G v a i l a b l e l i t e r a t u r e : M a l e y , ( 1 9 7 0 ) ; Campo ( 1 9 7 4 ) ;

Ybert, ( 1 9 7 9 ) ; Bonrieff i l l e and Riol let , (1980) ; Agwu

and Akanbi , ( 1 9 8 5 ) ; Agwu and A h i z e , ( 1 9 8 7 ) ;

f u n g a l s p o r e monographs , A lexopou l o s and Beneke ,

( 19621, Duru ( 1 9 8 5 ) , B e s s e y ( 1 9 6 4 ) and on r e f e r e n c e

c o l l e c t i o n of r e c e n t p o l l e n g r a i n s of N i g e r i a n

trees s t o r e d i n t h e Depa r tmen t of B o t a n y , U n i v e r s i t - y

o f N i q e r i a , Nsukka.

A n a l y s i s of v a r i a n c e was p e r f o r m e d f o r t h e

m o n t h l y and t h e y e a r t o t a l s a t t h e h e i g h t s f o r

the p a l y n a n o r p h s : p o l l e n q r a i n s and f Ungal s p o r e s -

T h e w e a t h e r c o n d i t i o n s in ~ s u k k a h a v e been

o b t a i n e d from t h e r e c o r d s a v a i l a b l e a t t h e

m e t e o r o l o q i c a l u n i t , Depa r tmen t of Crop Science,

U n i v e r s i t y of N i g e r i a , Nsukka.

PART 11

3 . 3 STUDY AREA

Obayi Lake i s l o c a t e d i n Nquru ~ s u k k a L - G - A -

w h i c h l i e s a p p r o x i m a t e l y b e t w e e n 1 at: l t u d e s 6O18' and

7 O 0 6 ' ~ and L o n g i t u d e s 0 6 ~ 5 2 ~ and 0 7 O 5 4 ' ~ , ( O f m a t a ,

1978). Nsukka is located i n the Mosaic of l o w l a n d

rainforest and secondary g r a s s l a n d , The lake i s

l o c a t e d in a depression of a p l a t e a u a t about 54H-blZm

(1SOU f t . ) above sea l e v e l and c o v e r s an a r e a of

approx imate ly 5000m2 (Fig. 1).

b

L E G E N 0 L E J J A 7073'~

I

.- ~ S U K K A TOWN B O U N D A R Y ' M A J O R R O A D

..' . , v ILL A'GE GHOU P B O ~ J N D A R Y /: S E C O N D A R Y R 9 A D

I G U R U V I L L A G E N A M E O B A Y I ( N G U R U ) L A K E

7 i g . l : Mop of Nsukko Town showing O b a y i (Nguru) Lake(548.6n-1 asl. 1

T h e l a k e i s m o r e o r less s t a g n a n t b u t o v e r f l o w s

t h r o u g h a n o r t h e a s t l o c a t e d c h a n n e l d u r i n g t h e r a i n y . s e a s o n . T h e brown c o l o u r c o u l d be a t t r i b u t e d m o s t l y

t o t h e n a t u r e o f t h e s o i l . D u r i n g t h e d r y s e a s o n t h e

l a k e dr ies u p completely a s ' a r e s u l t o f e v a p o r a t i o n

a n d t h e l o w e r i n g o f t h e w a t e r t a b l e .

3 - 4 SEDIMENT SAMPLING

T h e l a k e a t t h e t i m e of s a m p l i n g was d r y , w h i l e

t h e d r y i n s i t u v e g e t a t i o n h a d b e e n b u r n t . The

r e s u l t a n t e f f e c t w a s t h e d e s t r u c t i o n o f p l a n t s a n d

a n i m a l s of t h e l a k e a r e a . T h e s e d i m e n t w a s c o l l e c t e d

f r o m a d e p r e s s i o n a t t h e c e n t r e o f t h e l a k e -

P r i o r t o t h e c o l l e c t i o n , t h e g r o u n d s u r f a c e w a s

c l e a r e d o f a l a y e r o f a s h a n d t o p s e d i m e n t u p t o a

d e p t h o f 25cm. V e r t i c a l p r o f i l e ( c o n t i n u o u s

s t r a t i g r a p h y ) was s u b s e q u e n t l y c o l l e c t e d u s i n g a 1.5

metres l o n g h o l l o w c y l i n d r i c a l i r o n p i p e o p e n a t b o k h

e n d s . A p l a s t i c t u b e a b o u t 1 metre l o n g (Model - PP

s c h w e r e n t f lammber in 4102 B I ) w a s i n s e r t e d i n t o t h e

i r o n p i p e f o r s e d i m e n t c o l l e c t i o n . A t t h e lower e n d

of t h e p l a s t i c t u b e was a f f i x e d a c a t c h e r w h i c h h o l d s

b a c k c o l l e c t e d s e d i m e n t - T h e i r o n p i p e w a s t h e n

c a p p e d w i t h a s t a i n l e s s s tee l p l u g a t t h e u p p e r e n d .

40,

w i t h t h e lower e n d o p e n t h e i r o n p i p e was

g r a d u a l l y d r i v e n i n t o t h e s e d i m e n t t o a d e p t h o f 1

metre b y m e a n s o f a p l a s t i c - h e a d e d hammer, T h e core

w a s t h e r e a f t e r p u l l e d o u t m a n u a l l y . he p l a s t i c t u b e

c o n t a i n i n g t h e s e d i m e n t w a s p u l l e d o u t f r o m t h e i r o n

p i p e a n d s e a l e d a t b o t h e n d s t o p r e v e n t c o n t a m i n a t i o n

a n d loss o f material .

T h e s e d i m e n t i n t h e p l a s t i c tube was f r o z e n

solid i r i a d e e p f r e e z e r , and ,subsequently c u t i n t o

two l o n g i t u d i n a l h a l v e s by m e a n s of an electr ic m e t a l

band saw, MOSSNER HEKORD (GERMA HENGELO). S a m p l e s o f

the s e d i m e n t were t a k e n f r o m o n e h a l f , w h i l e t h e o t h e r

half w a s w r a p p e d w i t h a b rown c e l o t a p e a n d p r e s e r v e d

i n a d e e p f r e e z e r . The core s a m p l e m e a s u r e d 91cm ( a

d e p t h o f 116cm),

3-5 SEDIMENT DESCRIPTION

3 , 5 1 PHYSICAL PROPERTIES

he s e d i m e n t was d i s t i n c t l y s t r a t i f i e d i n t o n i n e

r e c o q n i s a b l e l a y e r s (A- I ) w i t h c h a r a c t e r i s t i c c o l o u r s

a n d t e x t u r e . ( ~ i q . I I a ) .

3 9 3 3 9 B 3 C C C C C C C C C C C C

C C C C C C C C C C C C

I 42.

3 - 5 - 2 SECTIONS ANALYSED AND TEXTURE

A t o t a l of 1 5 s a m p l e s , e a c h 2cm3 were t a k e n a t

a p p r o x i m a t e l y 5cm i n t e r v a l s from t h e t o p to b o t t o m .

However , c o n s i d e r a t i o n w a s g i v e n to t h e d i f f e r e n t

l a y e r s ( t e x t u r e and c o l o u r ) i n c o l l e c t i n g t h e s a m p l e s .

he r e s p e c t i v e s o i l t e x t u r e s were n o t e d as shown i n

~ i g u r e I I a and IIb).

43.

3.6 POLLEN EXTRACTION

The s u r f a c e o f e ach sample was s c r a p e d w i t h a

c l e a n s p a t u l a and washed w i t h d i s t i l l e d wa t e r t o

remove p o s s i b l e con t aminan t s . l O m l of c o n c e n t r a t e d

Hydroch lo r i c a c i d was added t o e ach sample i n a

p l a s t i c beake r and s t i r r e d a t i n t e r v a l s t o remove

c a r b o n a t e s . A f t e r 24 h o u r s , each sample was

c e n t r i f u g e d a t 2 ,000 r.p.m. f o r 5 minu t e s and t h e

s u p e r n a t a n t d i s c a r d e d . T h e p r e c i p i t a t e s w e r e washed

twice w i t h wa t e r t o remove t h e a c i d . ~ a c h wash W A S

f o l l vwed b y centrl f u g a t i o n .

The r e s i d u e from each sample was t r e a t e d w i t h

20ml of 40% H y d r o f l o r i c a c i d and a l l owed t o s t a n d f o r

4 8 h o u r s , s t i r r e d a t i n t e r v a l s t o e n a b l e a c i d r e a c t

i n t i m a t e l y w i t h t h e i n o r g a n i c components. The samples

were e a c h c e n t r i f u g e d t o r e c o v e r t h e r e s i d u e . The

r e s u l t i n g r e s i d u e s w e r e e ach washed twice w i t h wa te r

and c e n t r i f u g e d .

c he p r e c i p i t a t e s w e r e t h en c l e a n e d i n u l t r a s o n i c

w a t e r b a t h (BRANSONIC 220) a s d e s c r i b e d i n Dupont and

Agwu (1991 ) . The r e s i d u e o b t a i n e d a f t e r u l t r a s o n i c

c l e a n i n g was d e h y d r a t e d w i t h g l a c i a l a c e t i c a c i d and

a k e t o l y s e d (Erdtman, 1969) . The a c e t o l y s e d p r e c i p i -

t a t e s w e r e suspended i n g l y c e r i n e - a l c o h o l (2:l) and

s t o r e d i n p l a s t i c v i a l s .

44.

3-7 MICROSCOPIC STUDIES

T e m p o r a r y s l i d e s f o r m o r p h o l o g i c a l e x a m i n a t i o n

a n d p o l l e n c o u n t s w e r e made b y c o l l e c t i n g 0.3ml d r o p s

of t h e w e l l s h a k e n s u s p e n s i o n o n a s l i d e a n d c o v e r e d

w i t h 22mm x 22mm c o v e r s l i p , a n d s e a l e d o f f w i t h n a i l

v a r n i s h t o p r e s e r v e t h e m o u n t f o r a t l e a s t a b o u t 4

w e e k s .

P o l l e n c o u n t s w e r e d o n e a t x400 m a g n i f i c a t i o n

w h i l e m e a s u r e m e n t s a n d f i n e m o r p h o l o g i c a l e x a m i n a t i o n s

were c a r r i e d o u t a t xlUOO m a g n i f i c a t i o n - ( o i l

i m m e r s i o n ) . For t h e p o l l e n c o u n t s b e t w e e n 1 2 a n d

1052 p o l l e n g r a i n s were a c h i e v e d . Two s l i d e s w e r e

e x a m i n e d f o r e a c h s a m p l e . T h e m i c r o s c o p e u s e d was a

b i n o c u l a r KYOWA TOKYO, NO. 7 5 8 3 6 0 f i t t e d w i t h o c u l a r

micrometer f o r m e a s u r e m e n t of p o l l e n a n d s p o r e s

d i m e n s i o n s .

T h e i d e n t i f i c a t i o n o f p o l l e n were b a s e d o n

r e f e r e n c e c o l l e c t i o n s o f p o l l e n s l i d e s o f N i g e r i a n

p l a n t s s to red i n t h e D e p a r t m e n t of B o t a n y , u n i v e r s i t y

o f - . ~ i g e r i a , N s u k k a , a s w e l l a s from d e s c r i p t i o n s a n d

p h o t o m i c r o g r a p h s of p o l l e n a n d s p o r e s i n Campo, ( 1 9 7 4 ) ;

Ybert , ( 1 9 7 9 ) ; ~ o n n e f f i l l e a n d ~ i o l l e t , ( 1 9 8 0 ) ; Agwu b

a n d A k a n b i , ( 1 9 8 5 ) ; Agwu a n d ~ h i z e , ( 1 9 8 7 ) .

CHAPTER F'COH

RESULTS

PART 1

4.,1 AlRBORNL POLLEN AND SPORES

T h e a n a l y s i s o f a i r b o r n e p a l y n o m o r p h s t r a p p e d o v e r

t h e r o o f of F a c u l t y of B i o l q i c a l S c i e n c e s B u i l d i n q

( 1 5 m ) a n d B o t a n i c a l G a r d e n ( 1 . 8 m ) t h r o u q h o u t t h e

duration of t h e s t u d y ( F e b r u a r y , 1993 t o J a n u a r y , 1994)

d i s t l n q u i s t ~ e s the f 0 1 l o w i n q u n l t s r p o l l e n q r a i n s ,

spnrps of pte r i d o p h y t ~ s and fungi, and d i a t o m s .

P r a m t h e a r r r ~ u a l d i s t : r i b u t i m ot p o l l e n q r a i n s

c a p t u r e d i n the weakly s t u d y three s e a s o n a l p a t t e r n s

and mafor p o l l e n a b u n d a n c e were defined: Dry s e a s o n

( J a n u a r y t o A p r i l ) ; Lake D r y Segson - R a i n y

S e a s o n (May t o Auqus t : ) ; L a t e R a i n y S e a s o n - E a r l y

Dry S e a s m / t t a r r n a t t an ( ~ e p t e m b e r t o D e c e m b e r ) .

p t e r i d o p h y t e s c o u n t e d o u t of t h e t o t a l n u m b e r of

b i o l c w i c a l e l e m e n t s t r a p p e d (29, 213) c o n s t i t u t e

8377. (26.6036) and 2 0 8 (0.71%) r e s p e c t i v e l y . T h e r e w a s a t o t a l

of 4 1 p o l l e n t y p e s b e l o n q i n g t o 34 f a m i l i e s of h i q h e r

p l a n t s ( 2 7 d i c o t y l e d o n s and 7 m o n o c o t y l e d o n s ) .

N i n e t t e n and S i x t e e n p o l l e n t y p e s were i d e n t i f i e d t o

g e n e r i c and s p e c i e s . l e v e l s r e s p e c t i v e l y . S p o r e . t y p e s of p t e r i d o p h y t e s i d e n t i f i e d to q e n e r i c a n d s p e c i e s

l e v e l s were 1 a n d 1 4 r e s p e c t i v e l y able 11). .

Most of t h e p o l l e n q r a i n s were s p o r a d i c a l l y

d i s t r i b u t e d t h r o u g h o u t t h e m o n t h s of t h e y e a r . T h e r e

w a s a h i q h l y s i q n i f i c a n t d i f f e r e n c r P 0.01) i n t h e

non t h l y 1 1 0 1 l c n c u u n t . ~ . T h p highes t i n ( - i d e n c r of

monthly p o l l e n c a p t u r e was o b t a i n e d i n November

(18971 , f cr l lowed b y S e p t e m b e r ( 1 1 6 0 ) ~ O c t o b e r ( 9 5 9 ) ,

December ( 9 3 5 1 , F e b r u a r y ( 9 3 4 1 , J a n u a r y ( 7 2 0 1 , May

(541) and t h e n March ( 4 1 7 ) . C o m p a r a t i v e l y f e w e r numbcr

of p o l l e n q r a i n s w e r e r e c o r d e d i n J u l y ( 2 4 5 1 , J u n e ( 2 4 1 1 ,

A p r i l 9 ( 1 7 7 ) and A u g u s t ( 1 5 1 ) .

4 . 7 . 1 DRY SEASW ( J a n u a r y t o A p r i l )

A t o t a l of 2 2 4 8 p o l l e n g r a i n s were t r a p p e d

d u r i n g t h i s s e a s o n . T h e h i g h e s t number w a s i n

F e b r u a r y ( 9 3 4 1 , f o l l o w e d b y J a n u a r y ( 7 2 0 1 , March ( 4 1 7 )

a n d A p r i l ( 1 7 7 ) .

T h i s p e r i o d w a s m a r k e d b y a h i q h p r e p o n d e r a n c e

ofe t h e p o l l e n q r n i n s o f A l c h o r n e a - c o r d i f o l i a (168 )

Amarantheceae/Chenopodiaceae ( 3 1 , M i l i c i g excel ( 8 8 0 )

E l a e i s q u i n e e n s i s (3221, P o a c e a e ( 2 0 8 ) and C y p e r u s ( 1 7 ) . -- T h e p o l l e n of C a s u a r i n a - e q u i s e t i f 01 - ia w i t h h i g h e s t peak i r r

S e p t e m b e r ( 8 5 7 ) c o n t i n u e d u p t o J u n e as r e s i d u a l p o l l e n s t i l l

c a p t u r e d i n t h e a t m o s p h e r e . Amarantheceae/Chenopodiaceae

p o l l e n w h i c h h a d i t s p e a k . i n J u n e (18) e q u a l l y showed a

d e c r e a s e up t o A p r i l - T h e p o l l e n q r a : i n s o f A l c h o r n e a

c o r d i f o l i a had peak i n J u n e ( 8 2 ) a n d showed a d e c r e a s e --

i n F e b r u a r y ( 2 0 ) and March (51). T h e - Elaeis g u i n e e n s i s

pol Len w h i c h was f a i r l y represented i n t h e s e a s o n had peak

i n June ( 1 6 4 1 , w h i l e M i l l c i a _ e x c e l s q was h i q h l y e n c o u n t e r e d

s h o d i n q t l i q h f r e q u e n c y 11-1 February ( 5 ' 1 8 ) w h l c h was i t s peak

f o r t h e year. C y p e r u s p o l l e n was l o w and f a i r l y represented

without any p a r t i c u l a r peak.

Of t h e p o l l e n t y p e s t h a t h a d p e a k s i n J a n u a r y ,

E l a e i s g u i n e e n s l s h a d t h e h i g h e s t pol llen c o u n t ( l6rl) ,

f o l l o w e d by ------- C a s u a r i n a e q u i s e t i f o l i a , ( 1 4 3 ) . , P o a c e a e

( 1 0 4 ) and - A l c h o r n e a cocdif o l f a (82). J.n F e b r u a r y ,

M i l i c i a e x c e l s a h a d t h e h i g h e s t F ' r c q u e n c y ' o f p o l l e n - c a p t u r e d ( 5 7 8 ) . --- J u s t i c i a o c c u r e d o n l y i n J a n u a r y ( 1 6 1 ,

w h i l e t h e p o l l e n y r a i n s o f - A r i s t o l a c h i z , C o c h l o s p e r m u m ,

C o c c u l u s a n d P y c n a n t h u s w e r e t r a ~ p e d o n l y d u r i n g t h i s

s e a s o n r

T a b l e 3 : I r l d i v i d u n l p o l l e r i a n d p 1 : e r i d o p h y t i c -- s p o r e s t r a p p e d a t 15m a n d 1.U0m ( F e b r u a r y , 19.93 t o J a n u a r y , 1 9 9 4 )

P o l leri

P O a c e a e

kilicia e x c e l s a

I r v i n a i a a a b o n e n s i s

J u s t i c i a

l a t i f o l i a

A s t e r a c e a e - t u b type

C a s s i a b

P o l l e n

F a a a r a z a n t h o x v l o i d e s

I n d i a o f e r a

Syzyg iu rn g u i n e e n s e

coch loswer rnum

Trema guineense

Tectona q r a n d i s

G l o r i o s a s u p e r b a

A n t i d e s m a t y p e

P y c n a n t h u s a n g o l e n s i s

S e c u r i n i g a

C u r c u b i t a c e a e

A z a d i r a c t a i n d i c a

L i l i a c e a e - t y p e

B u r m a n n i a

C o n n a r a c e a e - t y p e

A g e r a t u m c o r n i z o i d e s

A r i s t o l a c h i a r i d i c u l a

B o t a n i c a l G a r d e n (1.80m)(%)

l(0.02)

p o l l e n

P t e r o c a r p u s

S e s b a n i a

c i s s u s

Prernna r e s i n o s a - t y p e

cardiosperrnurn

Salvadora

C i t r u s

Canthium -

Malvaceae

Loran t h e c e a e

S c o t t e l i a

Trichodesma

Ceiba pen tandra

Ja tropha c u r c a s

Bridelia f e r r u g i n e a

cucumis b

Vernonia arnygdalina

Mangifera i n d i c a

FBSB ( I sm)

( % )

2(0.02)

2(0.02)

l ( 0 .01 )

l ( 0 .01 )

l ( 0 .01 )

l (O.01)

l (O.01)

1 ( 0 - 0 1 )

l (O.01)

l (O.01)

l ( 0 . 0 1 )

l ( 0 . 0 1 )

l (O.01)

l (O.01)

l (O.01)

l (O.01)

l (O.01)

l (O.01)

l(O.01)

l (0 .01)

l (O.01)

P o l l e n

C r o t a l a r i a

E u p h o r b i a c e a e - t y p e

L u p h i r a l a n c e o l a t a

C a p a r i s

B e r l i n i a g r a n d i f o l i a -

C a s s i a m i m o s o i d e s

~ a p i l i o n a c e a e - t y p e

L a s i o d i s c u s m i l d b r e e d i i

V i rec ta m u l t i f l o r a

~ m e l i n a a r b o r e a

C a r i c a waDava

A n e i l e m a s e t i f e r u m

~ e ~ h r o l e ~ i s b i s e r r a t a

T h e l y p t e r i s t o t t a b

D o r y o p t e r i s

F B S B ( 1 5 m )

( % I

B o t a n i c a l G a r d e n ( 1 . 8 0 m ) ( % )

Asulenurn biafranurn

C v c l o s o r u s a u a d r a n a u l a r i s

Microgramma o w e r i e n s i s

~ e o s l e o t i o p s i s kemerunens i s

P t e r i s camerooniana

Davalia c h a e r o w h v l l o i d e s

Blechnurn a t t e n u a t o r

C y s t o p t e r i s f r a g i l i s

Elaphoglossum b a r t e r i

Phyma t o d e s s c o l o p e n d r i a

Oleandra d i s t e n t a

Hvwolewis s w a r s i s o r a

T h e l y p t e r i s zambesiaca

Stemodia s e r r a t a

L o n c h i t i s c u r r o r i

Other f e r n s .

B o t a n i c a l Garden

(1.8Orn)t%)

T a b l e 3: Month ly r e c o r d s o f p o l l e n g r a i n s t r a p p e d a t 15m ( ~ e b r u a r y , 1993 t o J a n u a r y , 1 9 9 4 )

Month

F e b r u a r y

March

~ p r i 1

May

J u n e

July

n u g u s t

S e p ternber

O c t o b e r

November

December

J a n u a r y

+

TOTAL

i i- ' R e p r e s e n t s t h e r e m a i n i n g d a y s of t h e month a f t e r t h e j 4 t h week. I I '

( X I , = L o s t Data .

4.2.2 LATE DRY SEASON - R A I N Y SEASON - (May t o A u g u s t )

T h e t o t a l p o l l e n t r a p p e d d u r i n g t h i s s e a s o n was

1 1 7 8 c o n s t i t u t i n g t h e leas t o f a l l t h e p o l l e n g r a i n s

t r a p p e d f o r t h e t h r e e s e a s o n s . T h i s s e a s o n was m a r k e d

b y a h i g h p a u c i t y o f p o l l e n g r a i n s c a p t u r e d i n A u g u s t

( 1 5 1 ) w i t h i t s h i g h r a i n f a l l , a n d r e l a t i v e l y h i g h e r

p o l l e n i n J u n e (241) a n d h i q h e s t i n May (541).

Casuarina e q u i s e t i f o l i a p o l l e n , w i t h peak i n J u l y

(118) d u r i n g t h e s e a s o n r e c e d e d i n A u g u s t ( 3 8 ) . T h e

q u a n t i t y o f p o l l e n g r a i n s o f Cambretaceae/Melatomatace;re,

A l c h o r n e a c o r d i f o l i a , Moraceae, E l a e i s g u i n e e n s i s and

P o a c e a e observed showed t h e y were a c o n t i n u a t i o n o f t h e

r e s i d u a l p o l l e n i n t h e a t m o s p h e r e t r a p p e d a f t e r t h e

p e a k o f t h e i r f l o w e r i n g p e r i o d s d u r i n g t h e p r e v i o u s

s e a s o n . ee l t i s h a d i t s p e a k i n March ( 3 6 6 ) a n d i t s

h i g h e s t o c c u r r e n c e f o r t h e y 'ear , i t s h o w e d a l o w

t u r n o u t i n o t h e r m o n t h s . he p o l l e n g r g i n s o f ~ i l i c i a

e x c e l s a was a1mos. t a b s e n t i n t h i s s e a s o n e x c e p t i n May

( 5 ) w h e r e r e s i d u a l p o l l e n was c a p t u r e d .

4.2. 3 LATE R A I N Y SEASON - E A R L Y D R Y SEASON/ HARMATTAN (SEPTLMBER TO DECEMBER)

T h e sum p o l l e n t r a p p e d d u r i n g t h i s s e a s o n ( 4 9 5 1 )

c o n s t i t u t e s t h e h i g h e s t f o r t h e t h r e e s e a s o n s . T h e

m o n t h l y r e c o r d o f p o l l e n t r a p p e d i n d i c a t e d t h a t t h e

h i g h e s t q u a n t i t y ' o f p o l l e n was c a p t u r e d i n ~ o v e m b e r

( 1 8 9 7 ) , f o l l o w e d . b y S e p t e m b e r ( 1 1 6 0 ) , October ( 9 5 9 )

a n d December (935)

D u r i n g t h i s s e a s o n C a s u a r i n a e q u i s e t i f o l i a h a d i t s

p e a k f o r t h e s e a s o n a n d y e a r i n S e p t e m b e r ( 8 5 7 ) . I t

w a s c o n t i n u a l l y t r a p p e d f r o m t h e a t m o s p h e r e u p t o

J a n u a r y ( 1 4 3 ) when t h e q u a n t i t y t r a p p e d i n c r e a s e d a n d

a g a i n d e c l i n e d u p t o J U r i c ( 7 ) . . c o r n b r e t a c e a e / ~ e l a s to-

mataceae , A l c h o r n e a c o r d i f o l i a a n d P o a c e a e p o l l e n h a d

the i r h i g h e s t o c c u r r e n c e s i n t h e m o n t h o f November

(84, 118 a n d 1 3 1 6 r e s p e c t i v e l y ) w h i c h was t h e i r p e a k s

f o r t h e y e a r . he p o l l e n of E l a e i s g u i n e e n s i s s h o w e d

a n i n c r e a s e f r o m O c t o b e r ( 1 1 7 ) a n d f i n a l l y m a r k e d i t s

h i g h e s t o c c u r r e n c e f o r t h e y e a r i n December ( 2 7 8 ) .

P o a c e a e p o l l e n w h i c h was c o n t i n u a l l y p r e s e n t i n t h e

a t m o s p h e r e showed a r e m a r k a b l e a b u n d a n c e f r o m

S e p t e m b e r ( 2 2 7 ) a n d e v e n t u a l l y h a d i t s h i g h e s t p e a k

f o r t h e y e a r i n November ( 1 3 1 6 ) . he p o l l e n g r a i n s

o f . ( ) lax , ~ c a c i a , P i n u s , H y m e n o c a r d i a a c i d a a n d M o r a c e a e

were s p o r a d i c a l l y a n d i n t e r m i t t e n t l y d i s t r i b u t e d

t h r o u g h o u t t h e y e a r .

T h e most p r e d o m i n a n t p o l l e n t y p e s i n d i s t r i b u t i o n

a n d q u a n t i t y c a p t u r e d t h r o u g h o u t t h e y e a r were t h o s e

of P o a c e a e ( 3 1 0 2 1 , E l a e i s q u i n e e n s i s ( 9 0 4 1 , C e l t i s .- --- (515) and A l c h o r n e a c o r d i f o l i a (335),

Of t h e t o t a l a i r s p o r a t r a p p e d ( 3 4 , 8 4 8 1 , p o l l e n

g r a i n s arrd spores of p t e r i d o p h y t e s c o n s i s t s of

6 1 4 3 (17.63%) a n d 8 3 ( 0 . 3 4 ) - 34 p o l l e n types were

l d e n t i f i c t d , c o r r s i s t i n q of 3 0 farni1ic.s ( 2 4 d i c o t y l e d o n s

and 6 m o n o c o t y l e d o n s ) w i t h 1 3 and .21 p o l l e n t y p e s

l d e n t i f i e d t o q e n e r i c and s p e c i e s l r w e l s r e s p e c t i v e l y .

Two a n d ten spore t y p e s of p t e r i d o p h y t e s were

i d e n t i € ied t o q e n e r i c and s p e c i e s level s r e s p e c t i v e l y .

I n a b s o l u t e v a l u e s t h e r e w e r e n o t i c e a b l e

f l u c t u a t i m s i n the q u a n t i t y of p o l l e n g r a i n s c o u n t e d .

However , t h e r e w a s n o s i g n i f i c a n t d i f f e r e n c e b e t w e e n

the m m t l y p o l l e n t o t a l s . T h e h i q h e s t i n c i d e n c e of

p o l l e n sum w a s f o u n d i n S e p t e m b e r ( 1 1 1 5 ) ~ f o l l o w e d b y

December ( 6 4 0 1 , J a n u a r y ( 6 0 9 1 , March ( 5 9 3 1 , November

( 5 8 5 1 , J u l y ( 5 2 4 ) arrd May ( 5 2 3 ) . O t h e r s i n c l u d e

( 2 5 3 ) a n d June ( 2 0 2 ) .

rxlo , ' , , , , , I , , O F M A M J J A S B N D J

Months

Fig I 1 1 Monthly pol len counts at heights of r1,nr l 1.Rn in -

T a b l e 4 : M o n t h l y records o f p o l l e n g r a i n s t r a p p e d a t 1.80m ( F e b r u a r y , 1 9 9 3 - J a n u a r y , 1 9 9 4 )

Month

F e b r u a r y

March

A p r i 1

May

June

J U ~ Y

A u g u s t

sep tember

October

Novenlber

December

J a n u a r y

Wk4 -- ( X I

1 0 4

39

58

67

9

29

477

1 1 3

1 1 3

(XI

8 0

TOTAL

* R e p r e s e n t s t h e r e m a i n i n g d a y s o f t h e month a f t e r t h e 4 t h week.

(%x) = ~ o s t D a t a .

T h e p o l l e n g r a i n s were u n e v e n l y d i s t r i b u t e d a l l

t h r o u g h o u t t h e y e a r i n t h e s t u d i e d s a m p l e s , The most

p r e v a l e n t and a b u n d a n t p o l l e n ? r a i n s t h a t o c c u r r e d

t h r o u g h o u t t h e y e a r were C a s u a r i n a e q u i s e t i f o l i a

( 2 6 8 6 1 , P o a c e a e ( 1 8 3 4 1 , B l a e i s q u i n e e n s i s (6631 ,

Moraceae ( 145) and Amaranthecaae/Chenopodiaceae.

i ; O t h e r a b u n d a n t p o l l e n t y p e s w e r e t h o s e of Milicia

e x c e l s a ( 3 0 7 1 , C e l t i s ( 2 7 3 1 , h l c h o r n e a c o r d i f o l i a

( 168 1 , Ccmbre t a c e a e / M e l a s t o m a t a c e a e ( 1091, and Cyperus

(90).

4 3 , DRY SEASW (JANUARY TO APRIL)

A t o t a l o f 1914 p o l l e n g r a i n s was t r a p p e d d u r i n g

t h e s e a s o n . I n J a n u a r y , 609 p o l l e n was c a p t u r e d ,

F e b r u a r y ( 3 9 4 1 , March ( 5 9 3 ) and A p r i l (3181 .

D u r i n g t h i s p e r i o d C a s u a r i n a e q u i s e t i f o l i a had i t s

peak i n J a n u a r y ( 338 1 , w h i l e I r v i n q i a g a b o n e n s i s

a p p e a r e d i n F e b r u a r y ( 9 0 ) w h i c h m a r k s it-s peak .

H i l i c i a e x c e l s a had i t s peak i n F e b r u a r y ( 1 0 2 1 , b u t

d i s a p p e a r e d from March o n l y t o a p p e a r a g a i n i n

September, T h e Moraceae p o l l e n i r a i n s w e r e r e p r e s e n t e d

b u t w i t h o u t any s p e c i a l peak. The p o l l e n of. C e l t i s wa,s

f i r s t . t r a p p e d i n F e b r u a r y ( 8 1 , b u t i n c r e a s e d up t o i t s

peak i n May (1381 . E l a e i s q u i n e e n s i s p o l l e n was

h i g h e s t i n March ( 2 6 2 1 wh ich was i ts peak of o c c u r r e n c e

f o r t h e y e a r . T h e p o l l e n o f P o a c e a e c a p t u r e d d u r i n g

t h i s s e a s o n was f e w a n d may h a v e r e s u l t e d f r o m

r e s i d u a l p o l l e n f r o m November ( 3 1 1 ) a n d December ( 2 8 2 )

p e a k p r o d u c t i o n s . T h e p o l l e n g r a i n s o f L o p h i r a ,

A c a c i a , a n d C a p p a r i s w e r e v e r y f e w a n d t r a p p e d o n l y

d u r i n g t h i s s e a s o n -

4 . 3 . 2 LATE DRY S E A S O N - R A I N Y SEASON -- (MAY TO AUGUST)

c he q u a n t i t y of [lo1 l e n g r a i n s t : r a p p x l dllrirlg

t h i s p e r i o d was low ( 1 5 0 2 ) and l e a s t for t h e t h r e e

seasons. he morl ths w i t h lower q u a n t i t y of p o l l e n

g r a i n s were A u g u s t ( 2 5 3 ) a n d J u n e (202). In May ( 5 2 3 )

a n d ~ u l y ( 5 2 4 ) , v e r t u a l l y e q u a l number o f p o l l e n

g r a i n s were c a p t u r e d .

T h e p o l l e n g r a i n s of M o r a c e a e were u n e v e n l y

d i s t r i b u t e d w i t h o u t a n y s p e c i a l ' p e a k . c e l t i s p o l l e n

w h i c h h a d i t s p e a k i n May ( 1 3 8 ) g r a d u a l l y d i s a p p e a r e d

i n A u g u s t b u t t h e r e s i d u a l 5 w e r e t r a p p e d u p t o

December . , T h e ~ l a e i s g u i n e e n s i s a n d P o a c e a e p o l l e n

were l o w t h i s ' s e a s o n , t h e n u m b e r s t r a p p e d may be

r e s i d u a l p o l l e n i n t h e a t m o s p h e r e . his s e a s o n

w i t h n e s s e d a h i g h q u a n t i t y of C a s u a r i n a e q u i s e t i f o l i a

p o l l e n t r a p p e d f r o m t h e a t m o s p h e r e w i t h p e a k i n J u n e

( 4 7 3 ) , t h o u g h w i t h h i g h e s t p e a k i n s e p t e m b e r ( 9 4 2 ) -

T h e p r e p o n d e r a n c e c o u l d be d y e t o l o c a l e f f e c t s

a r i s i n g f r o m t h e C a s u a r i n a trees i n t h e v i c i n i t y o f

t h e s a m p l i n g s i te .

4.3.3 LATE R A I N Y SEASON - EARLY D R Y SEASON/ HARMATTAN (SEPTEMBER TO DECEMBER)

T h e r e was a m a r k e d i n c r e a s e i r i t h e q u a n t i t y a n d

q u a l i t y uf p o l l e n t r a p p e d d u r i n g t t ~ i s s e a s o n , h e n c e i t

h a d t h e h i g h e s t p o l l e n sum ( 2 7 2 7 ) f o r t h e t h r e e s e a s o n s

c o m p a r e d . T h e r e w a s m u r e p o l l e n ~ I I S e p t e m b e r ( 1 1 1 5 ) ,

f o l l o w e d b y December ( 6 4 0 ) , ~ o v e m b e r ( 5 8 5 ) a n d

October ( 3 8 7 ) .

The p o l l e n g r a i n s o f ~ a s u a r i n a e q u i s e t i f o l i a w a s

h i g h e s t i n S e p t e m b e r ( 9 4 2 ) a n d t h i s w a s i t s h i g h e s t

p e a k f o r t h e y e a r . A l c h o r n e a c o r d i f o l i a a n d M i l i c i a

e x c e l s a p o l l e n g r a i n s r e a p p e a r e d i n ~ c t o b e r w i t h p e a k s

i n ~ o v e n l b e r ( 4 4 a n d 49 r e s p e c t i v e ) . ~ l a e i s g u i n e e n s i s w i t h

p o l l e n c o n t i n u e d f r o m t h e p r e v i o u s s e a s o n / p e a k a g a i n

i n ~ecenlber ( 1 4 3 ) . he p o l l e n o f P o a c e a e showed a

m a r k e d i n c r e a s e f r o m S e p t e m b e r ( 1 4 0 ) w h i c h g o t to

c l i m a x i n November ( 3 1 1 ) , a n d t h e v a l u e c o n s t i t u t e t h e

p e a k f o r t h e w h o l e p e r i o d . P y c n a n t h u s a n d P i n u s p o l l e n

g r a i n s were r e c o r d e d o n l y d u r i n g t h i s s e a s o n .

4-4 MONTHLY COUNTS OF ATMOSPHERIC FUNGAL SPORE CONTENT AT THE WEIGHT OF ABOUT 15M (FACULTY OF BIOLOGICAL SCIENCES BUILDING) FROM FEBRUARY 1 9 9 3 TO J A N U A R Y , 1 9 9 4

T h e t o t a l n u m b e r o f f u n g a l s p o r e s t r a p p e d f o r t h e

y e a r c o n s ' t i t u t e 1 7 0 8 6 ( 5 8 . 4 9 % ) o f t h e t o t a l number o f

b i o l o g i c a l e l e m e n t t r a p p e d ( 2 9 2 1 3 ) . o t h e r c o n s t i t u e n t s

i n c l u d e d i a t o m s 2694 (9 .22%) a n d o t h e r s ( b u r n t

e p i d e r m i s , p l a n t t i s s u e s a n d i n s e c t s ) 8 4 8 (2 .90%) .

4 1 s p o r e t y p e s were i d e n t i f i e d 1 . 0 qerieric l e v e l .

T h e r e were f l u c t u a t i o n s i n t h e c o n c e n t r a t i o n s o f

f u n g a l s p o r e s t r a p p e d i n t h e m o n t h s f o r t h e same

d u r a t i o n of t i m e . T h e m o n t h l y f u n g a l s p o r e a n a l y s i s

s h o w s t h a t t h e r e w a s a v e r y h i g h l y s i g n i f i c a n t d i f f e r e n c e

( P < 0 . 0 1 ) b e t w e e n t h e m o n t h l y s p o r e s t r a p p e d . T h e . h i g h e s t m o n t h l y f u n g a l s p o r e s o c c u r r e d i n November

( 2 5 8 6 ) , f o l l o w e d b y ~ecember ( . 2 5 7 8 ) , ~ e b r u a r y C 1 6 8 4 ) ,

J a n u a r y ( 1 6 5 3 1 , M a r c h ( 1 6 2 9 ) , O c t o b e r ( 1 2 2 9 ) a n d May

( 1 0 8 3 ) . C o m p a r a t i v e 1 y , less n u m b e r o f f u n g a l s p o r e s

w e r e c a p t u r e d i n J u n e ( 9 8 8 ) , A p r i l ( 9 3 8 ) , J u l y ( 9 0 3 ) ,

S e p t e m b e r ( 8 7 5 ) . a n d A u g u s t ( 8 4 0 ) .

' I 'able 6: ~ o n t h l y r e c o r d s o f f u r l g a l s p o r e s t r a p p e d a t 15111 ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1994)

* R e p r e s e n t s t h e r e m a i n i n g d a y s o f month a f t e r t h e 4 t h week.

( X ) = L o s t D a t a .

From t h e r e s u l t i t was n o t p o s s i b l e t o d e f i n e

t h r e e s e a s o n s w i t h r e g a r d t o a n n u a l d i s t r i b u t i o n o f

s p o r e s i n t h e a t r n o s p h e r e o f Nsukka. However , two

d i s t r i b u t i o n p e r i o d s were d i s t i n g u i s h e d ; J u n e t o

S e p t e m b e r a n d O c t o b e r t o March. his i n d i c a t e d

p e r i o d s o f l o w a n d h i g h a b u n d a n c e o f a t m o s p h e r i c

s p o r e c o n t e n t .

T h e s p o r e s of C l a d o s p v r i u m a n d C u r v u l a r i a were

abundant in F e b r u a r y ( 3 4 3 - peak), March ( 1 8 0 ) a n d

~ o v e m b e r ( I M ) , December ( 2 1 7 - p e a k ) r e s p e c t i v e l y .

A h i g h q u a n t i t y of spore t y p e s of D r e c h s l e r a /

~ e l m i n t h o s p o r i u r n were r e c o r d e d t h r o u y h o u t t h e y e a r ,

e s p e c i a l l y f r o m o c t o b e r ( 4 0 4 ) t o A p r i l ( 4 5 4 ) w i t h t h e

maximum p e a k i n March ( 7 7 6 ) . A g o o d number o f I

J o h n s o n ' s g r a s s s m u t , w i t h p e a k i n ~ e c e m b e ' r ( l 9 8 ) ,

~ e n t u r i a ( J u n e - 119 ) , P i t h o m y c e s (November - 4 2 ) , a n d

~ s p e r i s p o r i u m ( J u n e - 3 3 ) s p o r e t y p e s were r e c o r d e d

t h r o u g h o u t t h e y e a r . E n d o p h r a g m i e l l a s p o r e s were

n o t a b l y e n c o u n t e r e d f r o m J u n e t o November , w i t h p e a k

i n S e p t e m b e r ( 2 4 1 ) . he s p o r e t y p e s o f ~ i g r o s p o r a

a n d U s t i l a g o , n e x t i n a b u n d a n c e t o t h a t o f D r e c h s l e r a /

H e l m i n t h o s p o r i u m , w e r e h i g h l y r e p r e s e n t e d a l l b

t h r o u g h o u t t h e y e a r w i t h p e a k s i n December ( 5 9 6 ) a n d

I November ( 5 6 4 ) r e s p e c t i v e l y .

T h e f o l l o w i n g f u n g a l s p o r e s were c a p t u r e d

t h r o u g h o u t t h e y e a r e x c e p t f o r t h e m o n t h s r e c o r d e d

a g a i n s t them: c u r v u l a r i a ( A u g u s t ;

~ a n o d e r m a ( ~ a n u a r y , F e b r u a r y , M a r c h ) ; ~ l i o m a s t i x

( ~ p r i l , s e p t e m b e r ) ; s t e m p h y l i u m ( S e p t e m b e r ) ; a n d

T e t r a p l o a ( ~ u n e , A u g u s t ) . T h e s p o r e s o f A l t e r n a r i a ,

P l e o s p o r a , ~ e t r a c o c c o s p o r i u m , X y l a r i a a n d ~ l i o r n a s t i x

were s p o r a d i c a l l y a n d i n t e r m i t t e n t l y d i s t r i b u t e d .

Ti le nlos t a b u n d a n t a n d c c m n ~ o n l y e n c o u n t e r e d f u n g a l

spores t l l r o u g h o u t t h e year w e r e D r e c h s l e r a /

H e l m i r ~ t h o s p o r i u r n ( S 3 8 7 ) , N i g r o s p o r a ( 3 0 4 4 ) , u s t i l a g o

( 2 5 3 0 1 , E n d o p h r a m i e l l a ( 1 1 3 9 ) , C l a d o s p o r i u m ( 9 3 6 ) ,

~ o h n s o n ' s g r a s s s m u t ( 8 9 2 ) , V e n t u r i a - ( 4 0 4 ) , P i t h o r n y c e s

( 2 8 6 ) a n d A s p e r i s p o r i u m ( 2 2 2 ) . I

L a r g e q u a n t i t i e s o f D i a t o m s were e n c o u n t e r e d i n

t h e a t m o s p h e r e a l l t h r o u g h o u t t h e y e a r .

4.5 MONTHLY COUNTS OF ATMOSPHERIC FUNGAL SPORE CONTENT AT THE HEIGHT OF ABOUT 1-8M ( I N BOTANICAL G A R D E N ) FR'OM FEBRUARY, 1 9 9 3 TO JANUARY, 1 9 9 4

T h e r e l a t i v e c o n t r i b u t i o n o f f u n g a l s p o r e s t o

t h e t o t a l u n i t s ( 3 4 , 8 4 8 ) o f t h e a i r s p o r a was 2 6 0 8 4

J 7 4 . 8 5 % ) a n d d i a t o m s 2 1 2 8 ( 8 . 1 1 % ) . w h i l e a l g a e , p l a n t

t i s s u d s a n d b u r n t e p i d e r m i s c o n t r i b u t e d 4 3 5 ( 1 . 2 5 % ) .

4 3 s p o r e t y p e s were i d e n t i f i e d t o g e n e r i c l e v e l .

1

66.

here w a s a s t a t i s t i c a l d i f f e r e n c e ( P c 0 . 0 5 )

i n t h e m o n t h l y f u n g a l s p o r e s t r a p p e d a t 1.8M.

~ u m e r i c a l l y , t h e h i g h e s t m o n t h l y s p o r e s were

e n c o u n t e r e d i n ~ o v e m b e r ( 1 0 1 2 ) , f o l l o w e d b y A u g u s t

( 2 8 2 9 ) , December ( 2 7 7 6 ) , O c t o b e r ( 2 6 3 6 ) , JU.ne ( 2 2 6 5 ) ,

J u l y ( 2 2 6 4 ) , S e p t e m b e r ( 2 0 0 8 ) , and J a n u a r y ( 1 9 2 6 ) .

o t h e r s i n c l u d e March (l763), May (l304), F e b r u a r y

( 1 2 5 0 ) a n d A p r i l ( 1 1 5 6 ) -

I

I T a b l e 7: - Month ly r e c o r d s o f f u n g a l s p o r e s t r a p p e d a t 1.80m ( F e b r u a r y , 1 9 9 3 - J a n u a r y , 1 9 9 4 )

Month

F e b r u a r y

March

~ p r i 1

May

Jutle

J u l y

August

September

O c t o b e r

~ o v e r n b e r

December

J a n u a r y

TOTAL

1250

1 7 6 3

1 1 5 6

1304

2265

2264

2829

2 0 0 8

2636

4012

1 9 2 6

* R e p r e s e n t s t h e r e m a i n i n g d a y s of t h e month a f t e r t h e 4 t h week.

( X ) = L o s t d a t a .

T h e r e w a s n o d i s t i n g u i s h e d s e a s o n a l d i s t r i b u t i o n i n

t h e s p o r e s t r a p p e d a t 1.80m. However , more s p o r e s

were t r a p p e d f r o m J u n e t o D e c e m b e r , t h a n f r o m J a n u a r y

T h e s p o r e t y p e s o f C u r v u l a r i a , G a n o d e r m a ,

J u h n s o n 1 s g r a s s s m u t , Z r o r m i e l l a a n d S t e m p h y l i u m

were r e c o r d e d a l l t h r o u g h o u t t h e y e a r e x c e p t i n A u g u s t ;

~ e b r u a r y , March a n d J a n u a r y ; o q t o b e r ; F e b r u a r y , March

and J u n e ; a n d F e b r u a r y r e s l \ e c t i v e l y . A h i g h f r e q u e n c y

of spores of C l a d o s p o r i u m was o b s e r v e d f r o m November

t o J u n e , w i t h peak i n J a n u a r y ( 3 4 2 ) . T h a t o f C o p r i n u s

h a d p e a k i n J u n e ( 1 3 7 ) . . A s p e r i s p o r i u m s p o r e s w e r e

f a i r l y d i s t r i b u t e d with p e a k i n J u n e ( 9 1 ) . T h e s p o r e

t y p e s o f ~rechslera/~elminthosporium a n d ~ i q r o s p o r a

were h i g h l y a b u n d a n t d u r i n g t h e l a t e r a i n y / € a r l y d r y

s e a s o n ( s e p t e n l b e r t o December) a n d t h e Dry S e a s o n s

( J u n e t o A p r i l ) w i t h p e a k s i n ~ o v e n i b e r ( 1 0 2 0 ) a n d

December ( 5 0 7 ) r e s p e c t i v e l y . T h o s e o f E n d o p h r a m i e l l a

w i t h p e a k i n A u g u s t ( 3 8 1 ) ; ~ i t h o m y c e s w i t h p e a k i n

~ u g u s t ( 1 4 6 ) a n d ~ o r u l a w i t h p e a k i n J u n e (91), w e r e

m o r e f r e q u e n t l y e n c o u n t e r e d d u r i n g t h e ~ a i n y S e a s o n

(May t o A u g u s t ) . W h i l e t h e s p o r e t y p e s o f Ganoderma

( ~ u d u s t - 7 1 5 ) ; u s t i l a g o ( ~ o v e m b e r - 7 7 7 ) a n d V e n t u r i a

( J u n e - 2 5 7 ) were h i g h l y p r o m i n e n t d u r i n g t h e p e r i o d s

o f R a i n y S e a s o n (May t o A u g u s t ) t o L a t e R a i n y S e a s o n /

E a r l y Dry S e a s o n ( S e p t e m b e r t o D e c e m b e r ) .

T h e s p o r e s o f

~ e l t r a n i a , L e p t o s p h a e r u l i n a , T e t r a p l o a , ~ i l l e t i a a n d

X y l a r i a were f o u n d i n t e r m i t t e n t l y a n d i r r e g u l a r l y

d i s t r i b u t e d i n t h e a t m o s p h e r e a l l t h r o u g h o u t t h e

d u r a t i o n o f t h e s t u d y . T h e most a b u n d a n t a n d c o n s i s t e n t

f u n g a l spores e n c o u n t e r e d a l l t t l r o u g h o u t t h e y e a r were

E n d o p h r a m i e l l a

( 1 6 6 4 ) , v e n t u r i a ( 1 0 7 3 ) , ~ i t h o r n y c e s ( 1 0 0 2 ) , C o p r i n u s

( 6 2 9 ) , ~ o r u l a ( 6 0 2 ) a n d A s p e r i s p o r i u m ( 3 7 7 ) .

Of o t h e r e l e m e n t s c a p t u r e d , d i a t o m was c o n s i s t e n t L

i n t h e a t m o s p h e r e a l l y e a r r o u n d , w h i l e b u r n t

e p i d e r m i s w a s t r a p p e d o n l y f r o m ~ o v e r n b e r

4 06 COMPARISON O F PTERIDOI'HYTIC S P O R E S , DIATOMS A N D OTHER PARTICLES

4 6 1 PTERIDOPHYTIC SPORES

t o J a n u a r y .

A t 15m t h e r e w a s a t o t a l o f 2 0 8 s p o r e s

c o n s i s t i n g of 1 5 s p o r e t y p e s , w h i l e a t 1.80m t h e r e

w a s a t o t a l o f 8 3 s p o r e s c o n s i s t i n g o f 1 3 s p o r e t y p e s .

4 6 2 DIATOMS

T h e r e were r e l a t i v e l y a 1 a r q e . q u a n t i t - y o f

d i a t o m s t r a p p e d a t b o t h h e i g h t s . A t o t a l o f 2 6 9 4

were t r a p p e d a t 15m, w h i l e a t 1.80m a t o t a l of 2 1 2 8

d i a t o m s were c o u n t e d . D i a t o m s were t r a p p e d a t 15m

a n d 1.80rn more p a r t i c u l a r l y d u r i n g t h e d r y p e r i o d s

o r m o n t h s of F e b r u a r y ( 6 9 6 a n d 6 0 6 ) ; March (555 a n d

4 5 4 ) ; ~ o v e r r l b e r (108 a n d ,166); A p r i l (188 a n d 1 3 6 ) ' ;

wcember (57'7 arid 5 4 0 ) a n d J a n u a r y ( 2 0 7 arid 161) t h a n

during r a i n y m o n t h s of J u n e ( 4 2 a n d 2 2 ) , j u l y ( 2 9 a n d

I), A u g u s t ( 6 a n d 5 ) a n d S e p t e m b e r (11 a n d 5 ) .

4.6.3 OTHER PARTICLES

T h e r e was a b u n d a n c e o f b u r n t e p i d e r m i s t r a p p e d

a t 15m a n d 1.80m d u r i n g December ( 4 0 0 a n d 1 7 1 ) a n d

J a n u a r y ( 3 0 2 a n d 1 5 3 ) . T h e y were m o r e ( 2 6 9 4 ) a t 15m

t h a n a t 1.80m ( 3 3 4 ) . t'ieces o f p l a n t t i s s u e s were

t r a p p e d a s w e l l a s r a r e q u a n t i t y o f i n s e c t s a n d

A l g a l C&S.

T a b l e 8 : C o m p a r a t i v e summary of p a l y n o m o r p h s t r a p p e d m o n t l j l y a t 15m a n d 1.80m ( ~ e b r u a r y , 1 9 9 3 -

1

i J a n u a r y , 1 9 9 4 ) 4

4 . 7 COMPARATIVE EFFECTS OF METEOROLOGICAL FACTORS AT 15M AND 1-80M ON ATMOSFHERIC POLLEN AND SPORE CONTENT

4 - 7 - 1 RAINFALL

T h e c o m p a r a t i v e r e s u l t s ( F i g . V) s h o w e d t h a t

f r o m May t o A u g u s t d u r i n g t h e ~ a i n y S e a s o n , l o w

q u a n t i t y o f p o l l e n g r a i n s were t r a p p e d a t s5tes o f

15m a n d 1.80m. w i t h d e c r e a s e , i ~ ~ r a i n i n S e p t e m b e r

the q u a n t i t y of p o l l e n i n c r e a s e d f r o m 151 t o 1 1 6 0

a n d 252 t o 1 1 1 5 a n d s u b s e q u e n t l y d e c l i n e d a g a i n f r o m

959and 3 8 7 f n october f o l l o w i n g much r a i n a t 15m

a n d 1 . 8 0 m r e s p e c t i v e l y . T h e p e r i o d o f h i g h e s t

c o n c e n t r a t i o n w a s ~ o v e m b e r ( 1 8 9 7 ) a t 15m ( E a r l y d r y

s e a s o n / ~ a r m a t t a n ) a n d S e p t e m b e r ( 1 1 1 5 ) a t 1.80m

( L a t e r a i n y s e a s o n ) .

I n F i g . V I , w h i l e t h e q u a n t i t y o f s p o r e s were

h i g h d u r i n g t h e r a i n y s e a s o n (May t o A u g u s t ) a t

1.801~1, t h e r e were r e l a t i v e l y l o w s p o r e s a t 15m

w i t h i n t h e s a m e p e r i o d . H o w e v e r , a t b o t h s i t e s t h e r e

were c o m p a r a t i v e i n c r e a s e f r o m october ( 1 2 2 9 ) a n d

2 6 3 6 ) t o November ( 2 5 8 6 a n d 4 0 1 2 ) a t 15m a n d 1.80m

r e s p e c t i v e l y , a n d a c o n c o m i t a n t d e c l i n e ( 1 6 5 3 a n d

1 9 2 6 ) i n J a n u a r y .

able 9: Summary o f t o t a l p a l y n o m o r p h s t r a p p e d - f o r t h e o n e y e a r s a m p l i n g p e r i o d a t 15m a n d 1.porn ( F e b r u a r y , 1 9 9 3 - J a n u a r y , 1 9 9 4

P a l y n o m o r p h s

P o l l e n

F u n g a l Spores

P t e r i d o p h y t e s

A l g a l cells

uia tom

P l a n t ~ i s s u t ?

B u r n t E p i d e r m i s

TO t a l

- BOTANICAL

G A R D E N ( 1 * 8 0 m > ( % :

6 1 4 3 ( 1 7 . 6 3 :

?6O84( 7 4 . 8 5 :

8 3 ( 0 . 2 4 )

2 ( 0 . 0 1 )

2 1 2 0 ( 6 . 1 1 )

g S ( 0 . 2 7 )

3 3 4 ( 0 . 9 6 )

TOTAL ( % I

1401- E Rainfall

I Months

Fig V Etfect of ruinfail on pollen trappcd/~onth at heights, of ,15mw and. -+80&.,""" .6 ,

. - I L , I ( , . I . r I

- . < . '

$ 4 ! . .

KEY

O F M A M b

J J A S O N D Months

Fig V I Effcct of rainfall on fungal spores at heights of 15m ' and t8bm

trapped/ Month

4.7.2 TEMPERATURE

A t 15m, h i g h q u a n t i t y o : p o l l e n w e L e t r :p[)ed a t

0 0 a r a n g e of t e m p e r a t u r e o f 23.5 C t o 2 5 C , t h e l a r g e s t

q u a n t i t y i n November ( 1 8 9 7 ) c a p t u r e d a t t c ~ l r p e r a t u r e of

2 1 . 9 0 ~ ~ . A t 1.80rn, t h e l a r g e s t quant:if-.y i n ~ e p t e m b e r !

0 was t r a p p e d a t t e m p e r a t u r e of 2 3 - 5 C. rlowevcr,

m a j o r i t y of t h e p o l l e n g r a i r l s were t r a p l ~ e d d t r a r l y e

of t e m p e r a k u r s o f 23.5O~ t o 25Oc ( F i g . VII).

kiigh c o n c e n t r a t i o n o f f u n g a l s p o r e s were t r a p p e d

a t a r a n g e of t e m p e r a t u r e of 2 2 . 5 U ~ . T h e l a r g e s t

c o u n t ( 4 0 1 2 ) was o b t a i n e d a t 24.3 ' '~ . A t 15m, spores

were t r a p p e d a b u n d a n t 1 y a t t e m p e r n t u r e of 24. 20°c

( 2 6 7 8 i n D e c e m b e r ) a n d 2 4 . 9 ' ~ ( ? S O 6 i n ~ o v e m b c r ) ( P i g .

V I I I 1.

0 21 2 2 2 3 2 4 25 26 2 7 Mean - Temperature (OC )

f - 9 1

, Fig VII L I , e c t of temperature on quant i ty of po l len

trapped at heights of 15m and 1-80m

Mean Temperuture ( O C )

Fig v I I I Ef foc t of tcrnperature on quanti ty of fungal ..pores t rapped nt heig l : !~ of 15m and V80m

4 . 7. 3 RELATIVE I l I J M I D I T Y -- T h e m o n t h l y c o u n t s of p o l l e n g r a i n s d e c r e a s e d

w i t h i n c r e a s e i n r e l a t i v e h u m i d i t y e x c e p t i n S e p t e m b e r

wtiere t h e q u a n t i t y w a s t i ig l i ( 1 1 6 0 ar id 1 1 1 5 ) a t b o t h

s i t e s . ~t 15m, t h e h i g h e s t c o u n t w a s o b t a i n e d i n

~ o v e r n h ~ r ( 1 8 9 7 ) a t r e l a t i v e h u m i d i t y of G7.03% and

l e a s t j . 1 1 A i ~ q u s t ( 1 5 1 ) a t r e l a t i v e h u m i d i t y of 84.80%.

n t l . O O r n , t h e 1 h i g h e s t p o l l e n c o u n t was o b t a i n e d i n

:;cp terr~ber ( 1-1'15) a t rc?l.a t l v e h u r n l d i t y o f 0%. 7O'X, arid

l eas t i n J u n e ( 2 0 2 ) a t r e l a t i v e h u m i d i t y of 01.40%

T h e m o r i t h l y f u n y a l spores t r a p } ) e d a t 15m decreased

w i t h i n c r e a s e i n r e l a t i v e h u m i d i t y a p a r t f r o m ~ o v e l n b e r

( 2 5 8 6 ) t h a t s h o w e d i n c r e a s e a t 67. '83%. T h e h i g h e s t

c o u n t ( 2 6 7 8 ) a t 42 .54% was i n Decernber a n d l e a s t ' c o u n t

( 8 4 0 ) a t 84 .80% i n A u g u s t . A t 1.80rn t h e spore c o u n t s /

m o n t h t e n d e d t o i n c r e a s e w i t h r e l a t i v e i n c r e a s e i n

1i1,~rnidi. t y . H o w e v e r , t h e h i g h e s t c o u r l t ( 4 0 1 2 ) was

c ~ b t a i n e d a t a r e l a t i v e h u m i d i t y o f 6 7 . 8 3 % i n November ,

w h i - l e t h e l e a s t . c o u n t ( 1 1 4 6 ) w a s o b t a i n e d a t 65.50% i n

A p r i l ( F i g . x).

I

200 KEY i 0-Q 15m

A--A 1-80m U R H(Olo)lMonth

Months

Fi y I X Ettect of average.., . monthly Relative humidity on pollen t rappedl~onth at ' both heights

400k KEY

Fig X Effect of average monthly Relative humidity

i on fungal sporelrnonth. at both heights

:e 3

4 . 7 - 4 W I N D SPEED --

More p o l l e n were t r a p p e d when t h e r a n g e o f w i n d

speed w a s 1 0 - 2 6 k m / h r . a t 15m a n d 1.80m. T h e r e w a s a

p r o g r e s s i v e i n c r e a s e i n p o l l e n c o u n t a s t h e w i n d

s p e e d i n c r e a s e d f r o m 3 0 . 5 k m / h r . t o 7 8 k m / h r . a f t e r

w h i c h i t d e c l i n e d a t 9 9 . 5 1 k m / h r . ( ~ i g . X I ) .

T h e r e were more f u n g a l spores t r a p p e d a t t h e

range of l O k m / h r . to 2 6 k m / h r . a t 15m a n d l O k m / h r , t o

3 5 k m / h r . a t 1 - 8 0 m a s s h o w n i n F i g u r e XII-

KEY

Fig X I E f f e c t of W i n d Speed on pol len trapp,ed at 1

heights of 15m and 1-80m . ..

I I I ,,,,, I 1 l I 0 20 30 f+O 60 70 . 60 100

Wind S p e e d ( ~ m l h )

Fig X I A ,,tect of Wind Speed on fungal spores trapped I

at heights of 15m and 1430t-n

PART I1

4 . 8 SEDIMENT PROFILE '

T h e a n a l y s i s o f t h e s e d i m e n t - c o r e y i e l d e d 7 8

p o l l e n t y p e s b e l o n g i n y , t o 4 7 f a m i l i e s . 42 p o l l e n t y p e s

c o u l d b e c l a s s i f i e d to g e n e r i c a n d 2 9 t o s p e c i f i c l e v e l

r e s p e c t i v e l y , T h e s p o r e s o f f e r n s a n d f u n g i were

r e p r e s e n t e d i n a l m o s t a l l t h e s a m p l e s s t u d i e d .

~ d e n t i f i c a t i o n o f p o l l e n g r a i n s was made d i f f i c u l t

b y c o r r - o s i u n , c r u m p l i n g a n d b r e a k a g e o f some g r a i r l s .

Such g r a i n s t h a t were d i f f i c u l t t o i d e n t i f y were g r o u p e d

u n d e r i n d e t e r r n i n a t a , w h i l e t h e u n i d e n t i f i e d p o l l e n

g r a i n s w e r e p l a c e d u n d e r Varia.

4 . 8 0 1 ECOLOGICAL GROUPING

T h e p o l l e n t y p e s i d e n t i f i e d were p l a c e d i n t o f i v e

g r o u p s . T h e g r o u p i n g w a s d o n e i n a c c o r d a n c e w i t h t h e

p r e s e n t d a y n a t u r a l d i s t r i b u t i o n o f t h e p l a n t s . I n

d r a w i n g t h e p o l l e n d i a g r a m c o n s i d e r a t i o n was g i v e n t o

some p o l l e n o f h i g h e c o l o g i c a l s i g n i f i c a n c e . T h e

p l a n t s were p l a c e d i n t o g r o u p s modj t i e d a f t e r Aqwu a n d

Beug ( 1 9 8 2 1 , S t e e n t o f t ( 1 9 8 8 ) , Dupon t a n d Agwu ( 1 9 9 1 )

a n d Sowunmi ( 1 9 9 1 ) .

( a ) GROUP 18 RAlNFoREST TAXA

E l a e i s q u i n e e n s i s , B m b a x b u o n a p o s e n z e / C e i b a

p e n t a n d r a s , B e r l i n i a q r a n d i f l o r a , b l c h o r n c a c o r d i f ol iq,

I r v i n q i a q a b a n e n s i s , C a c s a l p i n a c e a e pep. ( S n c l l l a g e a ,

D e t e r i u m marrocarpum, Moraceae pp (FICUS, D o r s t e n i a , Militia_

e x c e l s a , Morus m e s o z y q i a , T r e c u l i a a f r i c a n a ) ,

B r a c h y s t c q i a e u r i c o m a , Newbou ld i a l a e v i s , C n e s t is-

f e r r u q i n e a , S c o t t e l i a , Uapaca, Leea q u i n e e n s i s , O l a x , - Bap_hi_a, E r y t h r o x y l u m , G a e r t n e r a , Oxyan thus , C i s s u s , - -

Faqara, Mimosa p y q r a and P y c n a n t h u s .

P o a c e a e , t a n n e a , C a s s i a , C o m b r e t a c e a e / M e l a s t oma-

t a c e a e , S o l e n o s t e m a r , R u b i a c e a e pp orre re ria, Canthiurn,

C r o s s o p t e r y x , Mussaenda ) , S a p i n d a c e a e ( A 1 l ophy l . u s ,

~ ~ r d i o s p e r r n u m ) , Aspe(raqus, ' G l or i o s a s u p e r b a , U r q i n i a , ' - J u s t i c i a , C u s s o n i a b a r t e r i , Cappa r iz b a n e n t o s a , . B r i d e l i q -

#

f e r r u q i n e a , Ant i d e s m a , Mimosa p u d i c a , Hymenocard in a c i d a ,

P h y l l a n t h u s , S e c u r i n e q a , T e p h r o s i a , P r o s o p i s a f r i c a n a ,

Syzyqium q u i n e e n s e , T a p i n a n t h u s , L o p h i r a , A f r o r m o s i a ,

Z i z i p h u s and Trema q u i n e e n s i s .

(=) GROUP 111: AWUATIC TAXA (MOIST CUNDITICPJ) AND FERNS

. Nymphaea, C y p e r u s , B u l b i t i s , M o n o l e t e and T r i l e t e . '

f e r n s .

( d ) -- GROUP I V : Rl\ITHROPOGENIC TAXA

P h a s e o l u s - c f - v u l g a r i s , D i o s c o r e a , P o d o c a r p u s ( ? ) , t u b i1.if e r o u s

AS t e r a c e a e . t y p e , A m s r a n t h e c e i l e / C t l e n o p o d i a c e a e ,

P l a n i h o t , P t e r o c a r p u s , ~ o m m e l i n a , n s a d i r a c t a i r ~ d i c a a n d

So lanu in s p p , -

GROUP V: OTHER TAXA AND VARIA-INDETERf*iINRVTn

I l e l i o t r o p i u m , Mdlvaceae , P r e ~ n n a 1 ; u p h o r b i a c e a e - -- ---' t y p e , V a r i a ( u n i d e i l t i f i e d p o l l e n g r a i n s ) a n d

i n d e t e r m i n a t a ( n o n - i c J e n t i f i a b l e p o l l e n g r a i n s ) . - -

4 - 9 ZOWlNG O F THE POLLEN DIAGRAM

T h e p o l l e r ~ D i a g r a m h a s b e e n d i v i d e d i n t o f o u r

p o l l e n z o n e s ( I - Iv) w h i c h a r e c o n s i d e r e d t o r e p r e s e n t

t h e rna j o r r e c o g n i z a b l e c h a n q e s i r l v e g e t a t i o n . T h e r e

a r e some p l a n t s w h i c h were i d e n t i f i e d o n l y i n o n e o r

t w o s a m p l e s a n d w i t h o n l y a f e w ~ o l l e n (1 or 2 ) .

( F i g . X I I I ) .

4 - 9 - 1 POLLEN ZONE ?a

Zone 1 i s c h a r a c t e r i z e d b y h i g h v a l u e o f total

r a i n f o r e s t t a x a b e t w e e n t h e b o r d e r t o P o l l e n Zone 11.

E 1 o l l c n z o n e l a i s c h a r a c t e r i z e d by low values o f

E l a e i s q u i n e e n s i s (Maximum 26%) a n d h i g h v a l u e f o r

C a s s i a - - arid a b s e n c e of -- L s n n e a . The v a l u e of M o n v l e t e

fcctls i s yrca tcr t h a n 5% (Phxxj.~nuni 10%)- ' ~ h e r e i s n

f o r the dielgr-ar~i i n t h i s z o n e . c a s s i a a l ) p e a ~ - c d w i L h a --- p ~ r c r n l ~ l r j c v a l u e ( 2 5 % ) . The rnorlolcte f e r n ~ a y p c a r

Loward the border b e t w e e n p o l l e n z o n e 'la and 1b.

P o l l e n Z o n e 1 D i s marked by a s h a r p i n c r e a s e i n

ttle v a l u e of E l a e i s g u i n e e n s i s (maximum &I%), f u r t h e r -- - decrease of Moraceae p . p ( < 5%) ; P o n c e a e ( <IS%).

A l c l m r n e a i n c r e a s e s i n v a l u e arid has a con t . in1 .1ous c l l r v c . ..--.,---------

b l o r n c e a e p . p d i s a p p e a r s i n the u p p c r l e v e l of tllc Z O I ~ C .

w h i l e t h e r e i s an i n c r e a s e i n R u b i a c e a e pp. L a n n e a a n d

P o d o c a r e ~ s - - (7) a p p e a r f o r t h e f i r s t t i m e a c c o ~ n p s n i e d by

w i t h a p r o n o u n c e d d e c r e a s e i n t h e n i o n o l e t e f e r n s (e 5%).

I n d i c a t o r s of human i m p a c t i n c r e a s e t o o v e r a l l h i g h e s t

peak ( 4 4 % ) , m o s t l y a c c o u n t e d f o r b y P h a s e o l u s cf

v u l g a r i s . T h e t r a n s i t i o n t o z o n e 1.1 s h o w s a d e c r e a s e

i n A l c h o r n e a - c o r d i f o l i a , E l a e i s g u i n e e n s i s , I )oaceae a n d

t h e t o t a l a b s e n c e o f M o r a c e a e .

4.902 POLLEN ZONE X I

Pollen zone 11 i s c h a r a c t e r i z e d l.)y a s l i g h t r e c o v e r y

and i n c r e a s e o f ~ l a e i s q u i r ~ e e n s i s -- (maximum 16%), t h e

i n c r e a s e u f U e r l i n i a q r a n d i f l o r a ( 7 % ) a n d a s l i g h t

irlcrease of A l c t t o r n e n c o r d i f o l i a , towards t h e e n d of

p o l l e n z o n e . M o r a c e a e p p . r e a p p e a r s , A f t e r t h e

d e c r e a s e o f sum s a v a n n a v a l u e t o w a r d s t h e e n d o f p o l l e n

z o n e , i t s h o w s a n i n c r e a s e (maximum 34%)' w h i c h i s

m a i n t a i n e d t h r o u g h o u t t h e z o n e . --' L a n n e a C o n i b r e t a c e a e /

Nelastornataceae, - S o l e n o s t e m o n a n d A s p a r a g u s o c c u r i n

t h i s z o n e , T h e f e r n s s h o w s p e c t a c u l a r p r e s e n c e - r n o n o l e t e (maximum 52%) a n d T r i l e t e (50%) w h i c h

s u b s e q u e n t l y d e c l i n e d s h a r p l y toward t h e e n d t o p o l l e n

T h e t r a n s i t i o n t o z o n e 111 s h o w s a decrease i n

~ l a e i s g u i n e e n s i s , A l c h o r n e a c ' o r d i f o l i a a n d a n ' i n c r e a s e --- i n h o a c e a e , s a p i r l d a c e s e p . p , N o r a c e a e p.p a n d t o t a l f o r

f e r n s .

4.3.4 POLLEN ZONL 111 --

~ 'o l l e r r z o n e 111 i s m a r k e d b y v e r y l o w v a l u e s

(maximum 5%) of ~ l a e i s - g u i n e e n s i s , a c c o m p a n i e d b y t h e

o c c u r r e n c e of ~ e r l i n i a g r a n d i f l o r a , -- R l c h o r n e a

c o r d i f o l i a a n d ~ r v i n g i a g a b o n e n s i s . M o r a c e a e p .p h a s --- - -- a c l o s e d c u r v e a n d v a l u e s h i y h e r t h a n e n d of p o l l e n

z o n e IS (maximum 8%) . Among t h e s d v a n n a flora t h e

region hut decrc?;lsc\s towards, p o l l c r ~ z o n e IV border.

Even as the l'oaceae decreases i r ~ the u p p e r p a r t at t - ~ I C

b o r d e r t o p o l l e n z o n e IV, t h e s h r u b s a n d trees:-

Lannea C a s s i a , Cornbretaceae/Melastomataceae a n d t h e --9

s c a n d e n t A s p a r a g u s make g o o d r e c o v e r y . T h e f e r n s

o s c i l a t e i n v a l u e i n t h e zone. C h a r a c t e r i s t i c a l s o of

t h e z o n e i s t h e f i r s t a p p e a r a n c e a n d c o n t i n u o u s c u r v e

o f c y p e r a c e a e (maximum 4 % ) .

~ n t h r o p o g e n i c i t ~ d i c a t o r s s h o w r e m a r k a b l e p r e s e n c e :

h i g h v a l u e s a n d c o n t i n u o u s c u r v e f o r P h a s e o l u s cf - v u l g a r i s a p p e a r a n c e o f D iosco rc?a w i t h c l o s e d c u r v e

? - a c c o m p a n i e d b y t h e weed o f R s t e r a c e a e t u b i l i f caous type

(maximum 9%) . T h e b o r d e r t o z o n e I V s h o w s a r e n e w e d

i n c r e a s e o f E l a e i s g u i n e e n s i s , A l c h o r n e a c o r d i f o l i a ,

I r v i n g i a ~ a b o n e n s i s , l w a c e a e , f e r n s a n d a d e c r e a s e o f

4.9.5 -- POLLEN ZONE I V ----

P o l l e n z o n e IV i s c h a r a c t e r i s e d b y a r e n e w e d

u p s u r g e i n t h e v a l u e o f E l a e i s g u i n e e n s i s (max.inium 38':;)

a n d t h e c o n t i n u e d o c c u r r e n c e of B e r l i n i a g r a n d i f l o r a , -- - A l c h o r n e a c o r d i f o l i a , - q a b o n e r i s i s a n d M o r a c c a e

p P u a c f a e p e r c e n t a g e s d e c r e a s e d f r o n i 38% t o 6%.

l ~ l r a s c o l u s cf v u 1 c ) ; l r i s alir~o:; t d i s r 3 1 ) j ) c - , ~ r ~ d ) w h i l e - lyp f?

As t e r a c e a e tubilifcr~as f d e c r e a s e d t o 9%. T h e M o n o l e t e

arid T r i l e t e f e r n s a r e a b u n d a n t .

CHAPTER F I V E

DISCUSSION AND CONCLUSION

PART I

T h e b i o l o g i c a l m a t e r i a l s t r a p [ ~ c ? d i n t h e c o u r s e o f

t h i s s t u d y r e f l e c t t h e a b u n d a n c e o f a i r b o r n e . . p o l l e n ,

sljores a n d o t h e r b i o p a r t i c l e s i n ~ s u k k a a t d i - f f e r e n t

h e i g h t s . s i m i l a r r e s u l t s were o b t a i n e d i n r e l a t e d

s t u d i e s by U g w u (g991); Agwu a n d O s i b e , ( 1 9 9 2 ) ; 'Mezua,

T h e r e w d s a h i g h l y s i g n i f i c a n t d i f f e r e n c e ( P < 0.01)

betweer1 t h e q u a n t i t y of p a l y r i o n ~ o r p h s t r a p p e d a t a h e i g l r t

o f 1.80m a n d t h o s e a t 1Sm ( T a b l e 9 ) . his d i f f e r e n c e

may b e a t t r i b u t e d t o t h e i m m e d i a t e s o u r c e s o f

a t m o s p h e r i c p o l l e n a n d s p o r e c o n t e n t n e a r t h e g r o u n d a s

c o m p a r e d t o t h o s e a t h i g h e r l e v e l s w h i c h a r e d e r i v e d

f r v m f a r t h e r f i e l d ( l o n g d i s t a n c e t r a n s p o r t ) .

A t m o s p h e r i c p o l l e n a n d s p o r e c o n t e n t a l s o r e s p o n d

d i f f e r e n t l y t o m e t e o r o l o g i c a l f a c t o r s ( t e m p e r a t u r e ,

l ~ u n d d i t y , r a i n f a l l a n d w i n d s p e e d ) a s w i l l b e d i s c u s s e d

. . f o r . t h e t w o 1 e v e . l ~ ( h e i g h t s ) .

5 . 1 POLLEN GRAINS TRAPPED AT H E I G H T S OF 1 5 M AND 1.80M

4

T h e r e l a t i v e a s s e s s m e n t o f t h e a t m o s p h e r i c p o l l e n

I . c o n t e n t a t h e i g h t s o f 15m a n d 1.80m r e v e a l e d t h a t t h e

q u a n t i t y of p o l l e n g r , a i n s t r a p p e d a t 15m ( 8 3 7 7 ' ) was

s i g n i f i c a n t l y d i f f e r e n t ( P < 0 . 0 5 ) f r o m t h o s e

t r a p p e d a t 1.80m ( 6 1 4 3 ) . K h a n d e l w a l ( 1 9 8 8 ) o b t a i n e d

1 9 5 2 1 a n d 1 8 4 9 3 a t 9m a n d 20cm r e s p e c t i v e l y .

A c c o r d i n g t o K h a n d e l w a l , ( l 9 8 8 ) , v e r t i c a l m i x i n g o f

a i r s p o r a i s o f t e n p o o r o v e r s h o r t p e r i o d s i n t h e

l o w e r a t m o s p h e r e r e s u l t i n g i n t h e d a y t o d a y

v a r i a b i l i t y i n t h e c o m p o s i t i o n .

~ l u a l i t a t i v e l y , a t o t a l of 34 f a m i l i e s of hir~hcr

p l a n t s ( 2 7 d i c o t y l e d o n s and 7 m o n o c o t y l e d o n s )

c o n s i s t i n g o f 4 1 g e n e r a were t r a p p e d a t 15m, w h i l e

members o f 3 0 f a m i l i e s ( 2 4 d i c o t y l e d o n s a n d 6 rnonoco-

t y l e d o n s ) c o n s i s t i n g o f 3 4 g e n e r a : were t r a p p e d a t

1.80m. T h e m o r e p o l l e n t y p e s t r a p p e d a t a h i g h e r

l e v e l may be a r e p r e s e n t a t i v e o f a w i d e r s o u r c e a r e a

a n d be t t e r m i x i n g , b e c a u s e i t i s more e x p o s e d t o a i r

t u r b u l e n c e , a n d r e a d i l y a c c e s s i b l e t o l o n g d i s t a n c e

t r a n s p o r t e d p o l l e n g r a i n s a s e x p r e s s e d b y B r i n g f e l t

e t a 1 ( 1 9 8 2 ) . Moreso, t h e k n o w l e d g e o f t h e aero- .-.- - ' d y n a r r ~ i c s o f p a r t i c l e t r a n s p o r t a n d c a p t u r e , s h o w s

t h a t t h e d i s p e r s a l o f p o l l e n g r a i n s i s c o n t r o l l e d b y

a n i n t e r a c t i o n of t .he t e r m i n a l v e l o c i t y o f t h e p o l l e n b

a n d w i n d v e l o c i t y . B a s e d o n t h i s , the a c t u a l

c o n c e n t r a t i o n o f p o l l e n i n t h e a t m o s p h e r e a t a n y p o i n t

96

down wind of the source b Lnfluenced by wing of the atmosphem

being tmppd at a higher level . This my have caused the difference

in the number of pollen Qpm trapped at each height.

The quantity of pollen i~~#pped at the two d l f f e m t heights dif f emce

indicated that there was a signfficentL(P~ 0.05) between the annual

that them was a highly signif icaert difsemce (P 4 0.01 ) in, the monthly

distribution of pllen in the air. The -,st f q s t l c y of p l l e n was

encountered in the month of November (Z!&Q), .followed by Septaher

(2n5) , kcember (195). October (3346) , Janu;ar~ (1329), February (1328),

May (1m) and Wch (1010). Caaparatively lower pollen grains were

trapped in July (W), April (495), June (4.43) and A ~ g ~ f s t (la) (Table

SO). Besed on the variations oberved in the mntkly pollen totals

three seasonal periods of varied pollen production have been mcarded:

(h) Ihy Season (January to A p r i l ) ;

(b) Early Rainy S!:ason to Rainy Season (May to A w t ) ;

(c) Ute Rainy Season to Early Dry Seasan/Narmattan (September to

. . I , , , , , : , . h i ? - . . , & i , , , ,, .

T a b l e 1 0 : C o m p a r i s o n o f m o n t h l y p o l l e n g r a i n s t r a p p e d a t 15m a n d 1.80m ( F e b r u a r y , 1 9 9 3 t o J a n u a r y , 1 9 9 4 )

-

Month

F e b r u a r y

March

A p r i l

Ma Y

June

J u l y

A u g u s t

Sep ternber

O c t o b e r

November

December

J a n u a r y

T o t a l

FBSB (15m)

~ o t a n i c a l G a r d e n (1.80m) -

T h e c h i e f s e a s o n of h i g h e s t p o l l e n p r o d u c t i o n was i n

L a t e R a i n y S e a s o n t o E a r l y Dry S e a s o n / H a r m a t t a n ( 7 6 7 8 )

a n d L e a s t i n t h e R a i n y S e a s o n ( 2 6 8 0 ) ; c f . Agwu a n d

O s i b e ( 1 9 9 2 ) .

~ o s t p l a n t s f l o w e r a t p a r t i c u l a r p e r i o d s o f t h e

y e a r , w h i l e some show i n c o n s i s t e n c i e s i n f l o w e r i n g

p e r i o d , t h o u g h e x h i b i t i n g maximum b l o o m i n g a t s p e c i f i c

s e s s ~ n s o f \ -he y e a r . T h i s a c c o u n t s f o r t h e p r e s e n c e o f

~ ~ o l l e n y r ~ l t l s i l l Lhc ,~ t - rno : ; l )hc~re a 1 1 y c d r round.

A c c o r d i n g t o Keay, e t - - a 1 ( 3 9 6 4 ) , i n N i g e r i a most t rees,

s h r u b s a n d some w i l d h e r b a c e o u s p l a n t s of t h e s a v a n n a

f l o w e r during t h e d r y s e a s o n . n u t E w u s i e , (1980) ,

p o i n t e d o u t t h a t a l l y e a r r o u n d f l o r a l a c t i v i t i e s i s

p e r c u l i a r t o t h e t r o p i c a l z o n e u n l i k e t h e t e m p e r a t e

zone w h e r e l o w t e m p e r a t u r e h a l t t h e s e a c t i v i t i e s i n

t h e w i n t e r . However , a n a e r o s o l s t u d y d o n e by M e l i a

(l984), a l o n g t h e G u l f o f G u i n e a d u r i n g t h e w i n t e r ( D r y

S e a s o n ) , s h o w s t h a t many of t h e p l a n t e n t i t i e s

i n t r o d u c e d i n t o t h e a t m o s p h e r e were t h r o u g h d u s t storm

a c t i v i t i e s a n d n o t f r o m a c t u a l ' p o l l e n p r o d u c t i o i - r a t

t h a t t i m e . N e v e r t h e l e s s , t h e s e f . a c t o r s may h a v e a l l

c o n t r i b u t e d i n i n c r e a s i n g t h e q u a n t i t y o f p o l l e n

t r a p p e d d u r i n g t h e l a t e r a i n y s e a s o n a n d e a r l y d r y

s e a s o n / h a r m a t t a n to t h e d r y s e a s o n . I n p a r t i c u l a r , t h e

h i g h q u a n t i t y o f d i a t o m s t r a p p e d d u r i n g t h e s e p e r i o d s

may h a v e a r i s e n f r o m d u s t storm.

T h e l e a s t q u a n t i t y o f p o l l e n g r a i n s ( 2 6 8 0 ) was

t r a p p e d d u r i n g t h e r a i n y s e a s o n (May to A u g u s t ) . T h e

l o w c o n c e n t r a t i o n may be a s a r e s u l t o f h i g h h u m i d i t y

a n d f r e q u e n t r a i n f a l l . w h i c h w a s h down s u s p e n d e d p o l l e n

i n t h e a i r a n d i n v a r i a b l y h i n d e r s t h e i r v e r t i c a l

t r a n s p o r t , t h u s r e d u c i n g p o l l e n c o n c e n t r a t i o n i n t h e

a t m o s p h e r e ( C a l l e j a , - e t -9 a1 1993). y b e r t ( 1 9 8 0 ) f o u n d

o u t t h a t r a i n a n d t h e d e g r e e of m v i s t u r e i n t h e air

p l a y arl i m p o r t a n t r o l e i n t h e c o n c e n t r a t i o n o f p o l l e n

i n c i r c u l a t i o n .

W i t h i n c r e a s e i n h e i g h t f r o m 1 . 8 0 m t o 15m t h e r e

were c o r r e s p o n d i n g i n c r e a s e s i n p o l l e n number o f

c o r d i f o l i a ( 1 6 7 t o 3 3 6 ) , H y m e n o c a r d i a a c i d a ( 3 8 t o 9 9 ) ,

Mi l i c ia e x c e l s a (313 t o 1 0 2 5 ) , P i n u s ( 4 t o 18 ) , C e l t i s

( 2 6 8 t o 5 1 6 ) , E l a e i s q u i n e e n s i s ( 6 6 9 t o 9 0 4 ) a n d

p o a c e a e (1034 t o 3 1 0 2 ) . W h e r e a s m o r e p o l l e n o f

g a b o n e n s i s ( 1 1 0 ) a n d C y p e r u s were

p r o d u c e d a t 1.80m. T h e v a r i a t i o n s o b s e r v e d i n t h e b

p o l l e n t y p e d i s t r i b u t i o n r e g a r d i n g h e i g h t d i f f e r e n c e

w a s n o t u n e x p e c t e d . his c a n n o t be w h o l l y a t t r i b u t e d

t o a e r o d y n a m i c l i m i t a t i o n s o f t h e p o l l e n t y p e s , b u t

p a r t l y t o m e t e o r o l o g i c a l f a c t o r s a n d l o c a l e f f e c t s

a r i s i n g f r o m g e o g r a p h i c a l d i s t r i b u t i o n o f p l a n t s o u r c e s .

A t l.80rn s i t e a r e l o c a t e d C a s u a r i n a trees a n d w e e d s a t

c lose i n t e r v a l . K h a n d e l w a l , ( 1 9 8 8 ) w o r k i n g a t 20cm

a n d 9rn f o u n d o u t t h a t a i r spora n e a r t h e i s

g r e a t l y a f f e c t e d b y f l u c t u a t i o n s i n immedia te l o c a l

s o u r c e s , w h i l e a t h i q h e r l e v e l t h e i m p a c t i s b y l o n g

d l s ta~lccr? t r a r ~ s p o r t . BU t nqwu a ~ ~ d I ) u ~ ~ o r ~ t , ( 1991) j ~ o i r ~ t c ? d

o u t t h a t s t u d y l o c a l i t i e s a n d t h e f a c t t h a t t h e

d i s t r i b u t i o n o f v a r i o u s t y p e s o f p o l l e n g r a i n s a r e

d i f f e r e n t l y a f f e c t e d b y d i s p e r s a l m e c h a n i s m s a n d

p r o d u c t i o n , t h e d i s t r i b u t i o n p a t t e r n s o f t h e d i f i e r e n t

t a x a may u n d e r l i e d i f f e r e n t c a u s e s . I n o t h e r w o r d s , I

s t u d y l o c a l i t i e s a n d g e o g r a p h i c a l d i s t r i b u t i o n of p l a n t s

a r e i n d i s p e n s a b l e f a c t o r s i n p o l l e n c a p t u r e a s o b s e r v e d

I from t h e r e s u l t . 1 d

1 T h e most common a n d p r e d o m i n a n t p o l l e n t y p e s

i n

t r a p p e d a t br3th h e i g h t s s u c h a s P o a c e a e , C e l t i s ,

! ! C a s u a r i n a e q u i s e t i f o l i a , ~ l a e i s g u i n e e n s i s , A l c h o r n e a

c o r d i f o l i a , M i l i c i a e x c e l s a a n d combretaceae/~elas to- I

1 rnataceae i n d i c a t e s t h a t e n t o m o p h i l o u s a n d a n e m o p h i l o u s

I p l a r l t s were j o i n t c o n t r i b u t o r s , a l t h o u g h a n e m o p h i l o u s

L o a c e a e , C a s u a r i n a e q u i s e t i f o l i a , ~ l a e i s g u i n e e n s i s a n d

M i l i c i a e x c e l s a p r e d o m i n a t e s . They a r e c o p i o u s

p r o d u c e r s o f p o l l e n , w i n d p o l l i n a t e d a n d a r e

p r e f e r e n t i a l l y t r a n s p o r t e d ( L i v i n g s t o n e , 1 9 6 9 1. T h e

a b u n d a n c e a n d d i s t r i b u t i o n p a t t e r n s o f p o l l e n g r a i n s i n

t h e a t m o s p h e r e a c c o r d i n g t o C a l l e j a -- e t a l , ( 1 9 9 3 )

d e p e n d s , o n t h e c o n s i s t e n c i e s i n t h e p r o d u c t i o n of

p o l l e n g r a i n s ( f l o w e r i n g p e r i o d s ) , t h e i r t r a n s p o r t ,

s o u r c e v e g e t a t i o n a n d n l e t e o r o l o g i c a l f a c t o r s .

he p e r i o d s o f rnaximurrl p o l i e n c v n t r i b u t i o n t o t h e

t o t a l c o u n t s a t 1 5 m a n d 1 . 8 U r n by C a s u a r i r ~ a e q u i s e t i f o l i a

( ~ a n u a r y , 1 4 3 a n d 3 3 8 ) ; J u l y , 118 a n d 4 7 3 ; S e p t e m b e r ,

U57 a n d 9 4 2 ) c o r r e s p o n d s w e l l t o t h e f l o w e r i n g p e r i o d s

i n J a n u a r y , May a n d S e p t e m b e r . The d i r e c t i o n o f w i n d

was r e f l e c t e d b y t h e a l t e r n a t e a b u n d a n c e o f i t s p o l l e n ,

e s p e c i a l l y i n A p r i l ( 8 a n d 1 1 4 ) ; May ( 1 3 a n d 2 7 3 ) a n d

J u n e ( 7 a n d 1 1 7 ) s h o w i n g s t r d n g l o c a l c o n t r i b u t i o n a t

1.80rn. T h e p e a k p e r i o d s o f M i l i c i a e x c e - l s a ( F e b r u a r y ,

5 9 8 a n d 1 0 2 ; M a r c h , 1 4 7 a n d 7 4 ) m a t c h e s i t s f l o w e r i n g

p e r i o d s o f December t o March ( K e a y , et &, 1 9 6 4 ) .

s i m i l a r l y , E l a e i s g u i n e e n s i s ( M a r c h , 68 a n d 2 6 2 ;

December, 2 7 8 a n d 1 4 3 ) a n d C e l t i s ( M a r c h , 366 a n d 1 3 8 )

s,how s imilar p a t t e r n s . T h e s e a s o n a l d i s t r i b u t i o n o f

g u i n e e n s i s a n d A l c h o r n e a c o r d i f o l i a are shown i n

F i g u r e s X I V a n d X V , w h e r e t h e y c l e a r l y d e f i n e d t h e

t h r e e s e a s o n a l p e r i o d s o f p o l l e n c o n c e n t r a t i o n i n t h e

a t m o s p h e r e v i z : J a n u a r y t o A p r i l ; May to A u g u s t ; a n d

S e p t e m b e r t o December,

P o a c e a e p o l l e n , m a j o r c o n t r i b u t o r t o t h e

a t m o s p h e r i c p o l l e n c o n t e n t of Nsukka w i t h p e a k s a t 15m

a n d 1.80m i n S e p t e m b e r ( 2 2 7 a n d 1 5 0 ) ; u c t o b e r ( 6 5 1 a n d

3 2 3 ) ; ~ o v e r r l b e r ( 1 3 1 6 a n d 3 1 1 ) and December ( 4 2 0 a n d 2 8 2 )

v e g e t a t i o n . G r a s s e s s u p p l y p o l l e n f r o m many s o u r c e s , . w i l d a n d c u l t i v a t e d p l a n t s a n d h e n c e , f l o w e r a l l y e a r

r o u n d (Usman, 1 9 9 0 ) , b u t w i t h r e d u c e d i n t e n s i t y i n some

s e a s o n s . T h e h i g h q u a n t i t y p r e s e n t a t 15m s h o w s how

e a s i l y i t c a n be t r a n s p o r t e d v e r t i c a l l y a n d h o r , i z o n t a l l y 1

sus i . , ended i n t h e a i r mass o v e r a l o n g p e r i o d o f time

( F i g . X V I ) . G e n e r a l l y , t h e maximum p e r c e n t a g e o f t h e

i n d i v i d u a l p o l l e n t a x a occurs a t t h e t i m e o f t h e i r

p o l l i n a t i o n ( C a l l e j a - e t - p a 1 1 9 9 3 ) , p e a k o f b l o s s o m i n g

p e r i o d .

' P i n u s p l a n t w h i c h t u r n s o u t l a r g e q u a n t i t y o f

p o l l e n g r a i n s was s p a r s e l y r e p r e s e n t e d a t 15m a n d 1.80m

(18 a n d 4). T h i s i n d i c a t e s t h a t t h e f e w p o l l e n t r a p p e d

m u s t h a v e b e e n p r o d u c e d b y a f e w s t a n d s i n t h e s o u t h / I I

' w e s t a r e a of ~ s u k k a r e l a t i v e t o t h e l o c a t i o n o f t r a p s

a n d some b y l o n g d i s t a n c e t , r a n s p o r t . 1 1 " ' , , , , 1 , '"id "'-'

1 , . , , . : , , ; ~ , s , , ,

KEY . - - ,

KEY

o--o 15m &-A 1.80m

J A s Months

Fig XV Sccrson variations in monthly Akhornea cordifolia - pollen cqu r~ t s obtained at 151-17 a n d 1.80 m

' O F M A M J J A S O N D J - 1 Months

Fig X V I Seasonal variations in mgnthly Grass ( Poacoae ) I ?.I

pollen counts obtained .'at 15m a n d 1-80m

T h e c h a r a c t e r i s t i c ~ u i n e a s a v a n n a / d e r i v e d s a v a n n a

s p e c i e s t h a t r e f l e c t t h e v e g e t a t i o n z o n e f a i r l y

r e p r e s e n t e d i n c l u d e S y z y g i u r n g u i n e e n s i s , C e l t i s ,

A l c h o r n e a c o r d i f o l i a , P o a c e a e , C a s s i a a n d Combre taccSae/

M e l a s t o m a t a c e a e . E v i d e n c e o f human i m p a c t i n c l u d e

A s t e r a c e a e , D e l o n i x r e q i a , A m a r a n t h e c e a e - C h e n o p r o -

d i a c e a e a n d b u r n t e p i d e r m i s . S i n g h a n d Buba, (1980)

a t t r i b u t e d t h e i n c r e a s e d i m p a c t t o h a b i t a t p r e s s u r e a n d

r a p i d u r b a n i z a t i u n ,

5 .2 FUNGAL SPORES TRAPPED AT t1EIGHTS O F 15M

T h e n u m b e r o f s p o r e s w h i c h r e m a i n i n t h e a t m o s p h e r e

a n d t h e i r e v e n t u a l p r e c i p i t a t i o n l a r g e l y d e p e n d s o n

n ~ e t e r o r o l o g i c a l v a r i a b l e s a n < t h e s i ze a n d s h a p e o f t h e

s p o r e s ( L y o n , e t a l , 1 9 8 4 ) . T h e l a r g e q u a n t i t y a n d

v a r i e d s p e c i e s o f f u n g a l s p o r e s t r a p p e d i n t h i s ' s t u d y

r e f l e c t s t h e l e v e l of d e g r e e of a b u n d a n c e of t h e s p o r e s

i n t h e a t ~ n o s p h e r e . T h e i r r e l a t i v e c o r n p o s i t i o n d o m i n a t e s

o ie r a l l o t h e r c o n s t i t u e n t of t h e p a l y n o r n o r p h s t r a p p e d .

T h e y c o n s t i t u t e a b o u t 58.49% ( 1 7 , O U 6 ) a n d 74.85% ( 2 6 0 8 4 )

o f t h e t o t a l b i o l o g i c a l m a t e r i a l s a t 15m a n d 1.80m b

r e s p e c t i v e l y . T h i s d a t a c o m p a r e s w i t h t h a t o f H u r t a d a

a n d G o i h m a n , ( 1 9 8 6 ) ; HOyes , ( 1 9 8 7 ) ; K h a n d e l w a l , ( 1 9 8 8 ) -

* '3 07.1

T h e c o m p a r a t i v e r e s u l t s o f t h e t w o d i f f e r e n t

h e i g h t s s h o w s t h a t t h e r e was a h i g h l y s i g n i f i c a n t

d i f f e r e n c e ( P < 0 . 0 1 ) b e t w e e n t h e t o t a l a n n u a l f u n g a l

s p o r e s t r a p p e d a t 1.80m ( 2 6 0 8 4 ) a n d 15m ( 1 7 0 8 0 ) . T h e

d i f f e r e n c e c o u l d b e a t t r i b u t e d t o l o c a l s o u r c e s i n t h e

~ o t a n i c a l G a r d e n f o r t h e lower l e v e l ( l O 8 O m ) , However ,

K h a n d c l w a l ( 1988) i n Lucknow, I n d i a t r a p p e d more s p o r e s

o n terrace ( 9 m ) t h a n o n g r o u n d (20crn) a f t e r o n e y e a r ' s

s t u d y . h t o t a l u f 41 a n d 4 3 f u n g a l s p o r e s were k r a p p e d

a t 15m and 1.80~1 r e s p e c t i v e l y .

T h e r e was a h i g h l y s i g n i f i c a n t d i f f e r e n c e ( P < 0 . 0 1 )

b e t w e e n t h e m o n t h l y c o u n t s o f f u n y a l s p o r e s a t b o t h

h e i g h t s c o m b i n e d . T h e h i g h e s t s p o r e c o u n t o c c u r r e d i n

~ o v e l r l b e r ( 6 9 5 8 ) , f o l l o w e d by December ( 5 4 5 4 ) , O c t o b e r

( 3 8 6 5 ) , A u g u s t ( 3 6 6 9 ) , J a n u a r y ( 3 5 7 3 ) , Marc11 ( 3 2 9 2 ) ,

J u n e ( 3 2 5 3 ) , J u l y ( 3 1 6 7 ) a n d F e b r u a r y ( 2 9 3 4 ) . O t h e r s

are S e p t e m b e r ( 2 8 8 3 ) , May ( 2 3 8 7 ) a n d A p r i l ( 2 0 8 4 )

able 11). More s p o r e s were t r a p p e d d u r i n g t h e E a r l y

Dry S e a s o n ( ~ o v e m b e r a n d D e c e m b e r ) . D u r i n g t h e d r y

s e a s o n , t h e a i r t u r b u l e n c e i s u s u a l l y h i g h c o u p l e d w i t h

t h e i n f l u e n c e o f h a r m a t t a n w i n d ( N E t r a d e wind) w h i c h - i n j e c t s ( r e f l o a t s ) a n a p p r e c i a b l e number o f p o l l e n a n d

s p o r e s i n t o t h e a t m o s p h e r e d u r i n g d u s t s t o r m ( A n d e r s e n , 1 9 7 4 ; M e l i a , 1 9 8 4 ) .

T a b l e 11: -- C o m p a r i s o n o f m o n t h l y f u n g a l s p o r e s t r a p p e d a t 15m arid 1.80m ( F e b r u a r y , 1 9 9 3 - J a n u a r v . 1 9 9 4 )

Month -- -

F e b r u a r y

March

April

June

J u l y

A u g u s t

S e p t e m b e r

O c t o b e r

November

December

J a n u a r y

TOTAL

FBSB ( ISM)

UOTANI CAL GARDEN (1.80M)

1 2 5 0

1 6 6 8

13.46

1 3 0 4

2265

2 2 6 4

2829

2 0 0 8

2 6 3 6

TOTAL ,

log-

A t 1.80m t h e r e w a s a n i n c r e a s e i n t h e q u a n t i t y o f

s p o r e s t r a p p e d d u r i n g t h e r a i n y s e a s o n (May t o A u g u s t )

i n c o n t r a s t t o t h e qua r i t i t y t r a p p e d d u r i n g t h e c o r r e s p o n -

d i n g p e r i o d a t 15m. R a i n d r o p s m o v i n g a t c e r t a i n k i n e t i c

e n e r g y may s p l a s h a n d d i s l o d g e f u n g a l s p o r e s o r w a s h o f f

s p o r e s o f f s p o r e b e a r i n g s t r u c t u r e s f r o m s u r r o u n d i n g

p l a n t s / c r o p s d u r i n g p r e c i p i t a t i o n ( L y o n , - e t -9 a1 1 9 8 4 ) .

S u c h s p o r e cloud r e l e a s e d l o c a l l y from t h e i m m e d i a t e

s u r r o u n d i r ~ g 1) la r l t s / c r o p s n e i l r t h e sarn l j l ing ur l i t a t 1 . M O r n

swells t h e q u a n t i t y of s p o r e s c a p t u r e d , t h u s c r e a t i n g t h e

s h a r p d i f f e r e n c e s o b s e r v e d .

T h e m a j o r i t y o f t h e f u n g a l s p o r e s t r a p p e d b e l o n g t o

t h e c l a s s o f A s c o m y c e t e s , B a s i d i o m y c e t e s a n d D e u t e r o m y -

cetes. heir a b u n d a n c e c a l l s f o r c a u t i o n a n d m a k e s thern

p a r t i c u l a r l y i n t e r e s t i n g b e c a u s e o f t h e i r a s s o c i a t i o n

w i t h p l a n t d i s e a s e s a n d p o l l i n o s i s i n man ( B e n n i n g h o f f ,

1 9 7 3 ; S p i e k s r n a , et al, 1 9 8 5 ; Budd , 1986 ; H u r t a d o a n d

G o i h m a n , 1 9 8 6 ; R o y e s ; 1 9 8 7 ) .

T h e most common a n d f r e q u e n t c o n t r i b u t o r s of s p o r e s

a t v . b o t h h e i g h t s i n c l u d e : Drechslera/Helminthosporium,

U s t i l a g o , N i g r o s p o r a , C u r v u l a r i a ,

A l t e r n a r i a , ~ o r u 1 a ' ~ n d o p h r a g m i e l l a . a n d - V e n t u r i a . *he '

h i g h d e g r e e of o c c u r r e n c e i n t h e a t m o s p h e r e

p a r t i c u l a r l y d u r i n g t h e w e t s e a s o n a t 1.80m may be

r e l a t e d t o t h e l a r g e nurnber o f h o s t : p l a n t s a n d r e l a t i v e l y

h i g h h u m i d i t y ( L y o n , -- e t a l , 1 9 8 4 ) , a s s h o w n i n t h e

r r l e t e o r o l o g i c a l d a t a i n ~ s u k k a . T h e r e s t r i c t i o n o f some

f u n g a l s p o r e s a t 15m ( C o c c o s p o r i u m a n d C u n n i n q h a m i e l l a

a n d 1.80m ( L x o s p o r i u r n , P y r e n o p h o r a , xirnerlia a n d Cordana -

t y p e ) o n l y , c o u l d be d u e t o l o n g d i s t a n c e t r a n s p o r t a n d

locdl r e s t r i c t io r~ of slpecies r e s p e c t i v e l y .

5 - 3 L'TLIII DVL'IIY'I'IC SIJOHES

T h e r e were a t o t a l o f 1 5 a n d 11 s p o r e t y p e s

i d e ~ ~ t i f i e d to g e n e r i c level a t 15m a n d 1 . 8 0 m r e s p e c t i v e l y .

T h e r e l a t i v e c o n t r i b u t i o n of t h e f e r n s p o r e s t o t h e t o t a l

b i o l o g i c a l e l e m e n t s t r a p p e d w a s 2 0 8 ( 0 . 7 1 % ) a t 15m a n d

8 3 ( 0 . 2 4 % ) a t 1.80m. F e r n s a r e d i s p e r s e d b y w i n d ( C a l l e j a

e t a l , 1 9 9 3 ) w h i c h m a k e s t h e i r s p o r e s more a b u n d a n t a t -- t ~ i y h e r l e v e l s b e c a u s e o f l o n g d i s . t a n c e t r a n s p o r t a n d t h e

e f f e c t o f m e t e o r o l o g i c a l f a c t o r s .

T h e mos t a b u n d a n t s p o r e - a t 1 5 m a n d 1.80m w e r e t h o s e

of ~ e p h r o l e p i s b i s e r r a t a ( 3 2 a n d 4 ) , T h e l y p t e r i s t o t t a

(13 a n d O ) , D o r y o p t e r i s ( 1 0 a n d 1 4 ) a n d D r y o p t e > i s

( 1 0 a n d 3 ) .

5.4 DIATOM

L a r g e q u a n t i t y o f d i a t o m was t r a p p e d , a t 15m . ( 2 6 9 4 ) 9 . 2 2 % t h a n a t 1 . 8 0 ~ 1 ( 2 1 2 8 ( 6 . 1 1 % ) ) . n i g h e r

q u a n t i t i e s w e r e t r a p p e d f r o m t h e e a r l y d r y s e a s 0 n

( N o v e m b e r t o D e c e m b e r ) t o d r y s e a s o n ( J a n u a r y t o A p r i l ) .

The p r e d o m i n a n c e d u r i n g t h e d r y s e a s o n i s a s s o c i a t e d

w i t h d u s t s t o r m / h a r ~ n a t t a n ( A n d e r s e n , 1 9 7 4 ; M e l i a , 1984;

C a l l e j d , e t a l , 1993), because a t t h i s p e r i o d l r ~ o s t p o o l s ,

l a k e s a n d p o n d l e v e l s , a n d t h c i r s u r r v u n d i n g s e n v i r o n m e n t

h a v e

5 . 5

e i t h e r r e d u c e d o r d r i e d up.

OTHER PARTICLES

M o s t i n s e c t s u n d e r g o e c d y s i s d u r i n g t h e h a r m a t t a n

( D e c e m b e r to J a n u a r y ) a n d t h i s t a l l i e d w i t h t h e p e r i o d

o f s c a l e a b u n d a n c e . T h e p l a n t t i s s u e s a n d b u r n t

e p i d e r m i s t r a p p e d a r e i n d i c a t i o n s o f b u s h f i r e w h i c h

a r e r a m p a n t f r o m November t o J a n u a r y . A c c o r d i n g to

I Agwu a n d O s i b e , ( 1 9 9 2 ) s u c h c o u l d b e u s e d i n m o n i t o r i n g - a

t h e f r e q u e n c y a n d i n t c n s i t y o f b u s h f i r e s .

5.6 f<LLATIONSHIPS BETWEEN THE A I R POLLEN A N D SPORE CONTENT, A N D METEOROLOGICAL FACTORS

5 . 6 . 1 R A I NFALL - b

! T h e q u a n t i t y o f p o l l e n t r a p p e d d u r i n g t h e r a i n y

' s e a s o n ( A p r i l t o A u g u s t ) ( F i g . V ) were l o w a t b o t h

41!2

h e i g h t s . R a i n f a l l h a s b e e n s u g g e s t e d a s b e i n g

r e s p o n s i b l e f o r w a s h i n g down a t m o s p h e r i c p o l l e n g r a i n s ,

t h u s r e d u c i n g t h e i r c o n c e n t r a t i o n i n t h e a i r d u r i n g t h e

r a i n y s e a s o n . M o r e s o , M a r k g r a f (1980) f o u n d t h a t a

m a j o r p e r i o d o f p r e c i p i t a t i o n r e s u l t e d i n a l m o s t c o m p l e t e

s e d i m e n t a t i o n o f p o l l e n . he h i g h q u a n t i t y o f p o l l e n

t r a p p e d i n S e p t e m b e r ( 1 1 6 0 a n d 1 1 5 ) a n d ~ o v e l n b e r ( 1 8 9 7

a n d 5 8 5 ) a t 15m a n d 1 . 8 0 m c o m p a r e s w i t h t h a t of

~ p i e k s m a , e t a 1 (1.985) w h e r e d a i l y p o l l e n c o u n t was -- q e r ~ e r a l l y h i g h or1 d a y s w i t t ~ o u t rr~ucti r a i n a n d r e l a t i v e l y

h i g h t e m p e r a t u r e .

he q u a n t i t y o f f u n g a l s p o r e s t r a p p e d a t 1,80m

showed r e l a t i v e i n c r e a s e a s r a i n y s e a s o n p r o g r e s s e d

( F i g . V I ) . A c c o r d i n g t o Royes ( 1 9 8 7 ) , r e l e a s e o f f u n g a l L

s p o r e s c o i n c i d i n g w i t h f a l l i n g r a i n s u g g e s t s t h a t t h e s e

s p o r e s a r e r e l e a s e d by t h e m e c h a n i c a l e f f e c t o f r a i n .

5.6.2 TEMPERATURE

A t a r a n g e o f t e m p e r a t u r e o f 23Oc t o 25Oc more

p o l l e n g r a i n s a n d s p o r e s w e r e t r a p p e d . However , t h e

h i g h e s t q u a n t i t y o f p o l l e n a t 15m ( 1 8 9 7 ) was t r a p p e d a t

a t e m p e r a t u r e o f 2 4 . 9 0 ~ ~ ( F i g . V I I ) a n d t h i s t a l l i e s

w i t h t h e h i g h e s t p e a k o f o c c u r r e n c e o f P o a c e a e i n

~ o v e m b e r ( 1 3 1 6 a n d 3 1 1 ) a t b o t h h e i g h t s ( F i g . V I I I ) .

T h e t e m p e r a t u r e o f 2 6 O ~ a t b o t h h e i g h t s d i d n o t

f a v o u r t h e t r a p p i n g o f much p o l l e n a n d s p o r e s .

5 . 6 . 3 R E L A T I V E HUMIDITY

A t a r e l a t i v e l y h i g h h u m i d i t y f e w p o l l e n w e r e

t r a p p e d a t b o t h h e i g h t s e x c e p t i n S e p t e m b e r w h e r e t h e

number was h i g h d u e t o t h e e f f e c t o f o t h e r m e t e o r o l o g i c a l

f a c t o r s a t t h a t month ( ~ i g . I X ) . A t 1.OOm f u n g a l

s1,ores showed a n i n c r e a s e i n number w i t h i n c r e a s e i n

r e l a t i v e h u m i d i t y w h i l e a t 1 5 m t h e l e a s t number o f

s p o r e s (840) were r e c o r d e d when t h e r e l a t i v e h u m i d i t y

was h i g h e s t 84.80% ( F i g . x ) . Chen a n d Haung (1980)

o b s e r v e d t h a t a i r b o r n e p o l l e n a n d s p o r e s i n c r e a s e d w i t h

h i g h e r t e m p e r a t u r e s a n d lower h u m i d i t y t h o u g h v a r y i n g

w i t h d i f f e r e n t t a x a .

5.6.4 W I N D SPEED

T h e r e s u l t s h o w s t h a t h i g h e r w i n d s p e e d d i d n o t

f a v o u r t r a p p i n g o f l a r g e y u a n t i t y o f p o l l e n g r a i n s a n d

s p o r e s a t b o t h h e i g h t s . More p o l l e n a n d s p o r e s were

t r a p p e d a t t h e r a n g e o f w i n d v e l o c i t y o f 10-30km/hr .

( F i g s . X I a n d X I I ) . S ince t h e d i s p e r s a l r a t e d e p e n d s

on. t h e e x t e n t of a i r movement ( H e d d i a n d H e d d i , 1985;

Lyon - e t - 9 a 1 1 9 8 4 ; C a l l e j a -- e t a l , 1 9 9 3 ) , t h e m a g n i t u d e

o f t h e w i n d v e l o c i t y d e t e r m i n e s t h e d i s p e r s a l a n d

c o r l c e n t r a t i o n o f p o l l e n a n d s p o r e s i n t h e a i r a t a n y

p o i n t i n t i m e .

PART I1

POLLEN DIAGRAM

T h e p o l l e n d i a g r a m s h o w s a r e m a r k a b l e i n c r e a s e i n

the a p p e a r a n c e of woody a n d h e r b a c e o u s species f r o m

the lowest-. mrle t:o fhe upper most z o n e . 'rhe d iagram

i n zones I a n d z o n e 11, shows a r e l a t i v e l y h i g h presence

o f ~ l a e i s g u i n e e n s i s a n d lower p e r c e n t a g e o f trees a n d

s h r u b s s u c h a s A l c h o r n e a c o r d i f o l i a , B e r l i n i a

g r a n d i f l o r a , Lanr iea , C a s s i a , A s p a r a g u s , ~ u b i a c e a e pp .

a n d C o m b r e t a c e a e / M e l a s t o n ~ a t a c e a e - T h i s t y p e o f b

v e g e t a t i o n s t r u c t u r e i s f o u n d i n a wooded s a v a n n a

v e g e t a t i o n w i t h l o w forest c o v e r (Sowunmi , 1 9 9 1 ;

I U a l l o u c h e a n d ~ e u m a n , 1 9 9 5 ) -

I j H o w e v e r , t h e h i g h p e r c e n t a g e o f s a v a n n a t a x a

i ( 3 5 % t o 47%) a t t h e l o w e s t z o n e , a c c r u i n g m o s t l y f r o m

k J o a c e a e , a n d t h e a p p e a r a n c e o f C a s s i a , A l c h o r n e a

c o r d i f o l i a a n d ~ombretaceae/~elastomataceae i n a s s o c i a -

, t i o n w i t h a b u n d a n t M o r a c e a e p p (50%) a r e i n d i c a t i v e o f

a s a v a r l n a v e g e t a t i o n - T h e f o r e s t c o v e r may h a v e b e e n

m o d i f i e d f o l l o w i n g t h e d i s a p p e a r a n c e o f M o r a c e a e p p .

a n d t h e s u b s e q u e n t r e c o v e r y o f ~ l a e i s g u i n e e n s i s i n

a s s o c i a t i o n w i t h woody t a x a s u c h a s A l c h o r n e a

c o r d i f o l i a , L a n n e a , Combretaceae/Melastomataceae n o t e d

i n z o n e s l b a n d 11 ( c f . sowunmi , 1 9 9 1 ; M a l e y , 1 9 8 9 ) . *

Moreso, t h e i n c r e a s e i n P h a s e o l u s c f . v u l g a r i s ( 4 4 % )

a n d t h e h i g h p e r c e n t a g e of A s tcraceae ( 2 1 % ) , s t r o n g l y

s u g g e s t t h e e x i s t e n c e o f f a r m i n g a c t i v i t i e s . T h e h i g h

oscilla t i o r 1 o f t h e ferns, p a r t i c u l a r l y t h e monole te ferns

i n z o n e r I i s i r ~ d i c a t i v e of r e d u c e d w a t e r l e v e l o f t h e

l a k e ( M a l e y , 1989; J a h n s , 1 9 9 5 ) .

F u r t h e r u p i n z o n e 111, t h e r e i s a n o t a b l e p a u c i t y

o f ~ l a e i s g u i n e e n s i s p o l l e n . his p e r i o d was a l s o

a s s o c i a t e d w i t h t h e r e a p p e a r a n c e of M o r a c e a e p p . ,

I r v i n g i a g a b o n e n s i s , B e r l i n i a g r a n d i f l o r a a n d r e l a t i v e l y

h i g h p e r c e n t a g e o f s a v a n n a t a x a . T h e h i g h p e r c e n t a g e o f

s a v a n n a s p e c i e s i s a t t r i b u t e d t o m o s t l y u p s u r g e o f

P o a c e a e , a n d o t h e r w o o d l a n d s h r u b s , h e r b s a n d trees

w i t h c h a r a c t e r i s t i c s p e c i e s s u c h a s L a n n e a , c a s s i a ,

S o r e n o s t e m o n , ~ombretaceae/Melastomataceae, Trema

g u i n e e n s i s , S a p i n d i c e a e p p . , l l y r n e n o c a r d i a a c i d a a n d

A s p a r a g u s . A c c o r d i n g t o J a h n s ( 1 9 9 5 ) , h i g h P o a c e a e 6

p o l l e n p e r c e n t a g e a r e f o u n d i n modern p o l l e n s p e c t r a o f

t h e s a v a n n a s o u t h o f t h e S a h a r a . T h e t r e n d t h e r e f o r e

may b e i n d i c a t i v e o f well d e v e l o p e d s a v a n n a v e g e t a t i o n

o r t h e m o d i f i e d s a v a n n a m o s a i c p a t t e r n o f o p e n f o r e s t

f o r m a t i o n ( M a l e y , 1 9 8 9 ; Sowunmi , 1 9 9 1 ) .

T h e u p p e r most z o n e I V w i t h n e s s e d a r e m a r k a b l e

c h a n g e i n t h e a b u n d a n c e of p o l l e n t y p e s . g l a e i s

q u i n e e n s i s r e c o v e r e d , a t t a i n i n g a p e r c e n t a g e o f 38%;

Bombax b u o n o p o z e n s e / C e i b a p c n t a n d r a a n d C a e s a l p i n a c e a e

pp. of t h e r a i n f o r e s t a p p e a r e d f o r t h e f i r s t t i m e .

Herbaceous p l a n t s a n d s h r u b s o f t h e s a v a n n a t a x a became

m o r e p r o m i n e n t . P o a c e a e p o l l e n r e a c h e d h i g h v a l u e s a t

t h e m i d - p o i n t o f t h i s z o n e b u t d e c r e a s e d d r a s t i c a l l y

f r o m 38% t o 5% a t t h e t o p o f t h e z o n e . he f a r m i n g

a c t i v i t i e s t h a t g o o n a r o u n d t h e l a k e c o u l d b e a s s o c i a -

t e d w i t h t h e d e c r e a s e . H o w e v c r , by a n a l o g y w i t h t h e

w o r k of M a l e y ( I g U g ) , a t l a k e ~ a r o m b i Mbo o f W e s t e r n

~ a m e r o o n , t h e i n c r e a s e i n h e r b a c e o u s p l a n t s i s

i n d i c a t i v e o f t h e e s t a b l i s h m e n t o f more o p e n forest

v e g e t a t i o n o r t h e d e v e l o p m e n t o f a s a v a n n a mosaic

! I p a t t e r n o f f o r e s t a n d o p e n f o r m a t i o n s . he h i g h

o s c i l l a t i o n o f f e r n s u p t o t h e u p p e r most z o n e , c o u p l e d

1 wi.th t h e p e r s i s t e n c e o f C y p e r u s a n d t h e a p p e a r a n c e o f 1

~yrnphaea i s s u g g e s t i v e o f p e r i o d i c l o w e r i n g o f T a k e

I l e v e l p r o b a b l y t o v e r y s h a l l o w m a r s h y p o o l w h i c h d r i e s 1

up i n t e r m i t t e n t l y (Sowunmi, 1991) d u r i n g p r o l o n g e d

d r y s e a s o n , T h e a q u a t i c p l a n t s d i s p l a y l o c a l

s i g n i f i c a n c e ( J a h n s , 1 9 9 5 ) and t h e p e r i o d t h e n may be

r e l a t e d t o a s i m i l a r d r y c o n d i t i o n o b s e r v e d i n t h e

I I l a k e d u r i n g t h e t i m e o f t h e s a m p l e s s t u d y .

Remarkab ly , of s i g n i f i c a n c e i n t h e d i a g r a m i s t h e

p e r s i s t e n c e of p i o n e e r f o r e s t t a x a i n t h e p r o f i l e s u c h

as A l c h o r n e a c o r d i f o l i a , E l a e i s q u i n e e n s i s and

Combretaceae/Melastomataceae a l l t y p i c a l of s e c o n d a r y

n a t u r a l formations of t h e Guineean t r a n s i t i o n woodland ,

t h a t is , t r a n s i t i o n be tween r a i n f o r e s t and t h e wooded

g r a s s l a n d (Dupcnt and Agwu, 1992). The a s s o c i a t i o n of

t h i s p i o n e e r t a x a w i t h a r e l a t i v e l y h i g h p e r c e n t a g e of

P o a c e a e i n t h e d i a g r a m i s s u g g e s t i v e of t h e e s t a b l i s h m e n t I

of w e l l d e v e l o p e d Mosa ic s a v a n n a v e g e t a t i o n w i t h open

f o r e s t i n t h e v i c i n i t y of t h e l a k e (Sowunmi, 1991;

Neumann, & & ( i n p r e s s ) 1, A l s o B a l l o u c h e and Neumann,

( 1995 1, a s s o c i a t e d weak r e p r e s e n t a t i m of a r b o r e a l

p o l l e n by h i g h P o a c e a e v a l u e s 'in an e n t i r e p r o f i l e t o

an open t y p e of v e g e t a t i c n .

Ant h r o p o g e n i c . i n f l u e n c e . became e v i d e n t i t ight f rom

t h e P o l l e n z o n e l a , t y p i f i e d b y P h a s e o l u s o f . v u l q a r i s b

and A s t e r a c e a e t u b i l if e r o u s t y p e . D i o s c o r e a a p p e a r e d i n L.

, P o l l e n o n e I11 and p e r s i s t e d t o t h e P o l l e n z o n e IV.

B u r n t e p i d e r m i s , i n d i c a t i v e o f b u s h b u r n i n g ,

a r g i c u l t u r a l o r p a s t o r a l a c t i v i t i e s (Agwu a n d O s i b e ,

1992; B e h l i n g ( i n p r e s s ) were p r e s e n t . T h e a b u n d a n c e

o f P h a s e o l u s cf . v u l q a r i s p o l i e n may be d u e t o

e x p a n s i o n o f f a r m a c t i v i t i e s o r t o l o c a l f a c t o r s

a r i s i n g f r o m p o o r p o l l e n d i s p e r s a l w h i c h i s v e r y common

w i t h e n t e n l o p h i l o u s p l a n t s ( L i v i n g s t o n e , 1369; Moore a n d

Webb, 1978; D u p o n t , 1 9 9 3 ) .

5.8 CONCLUSION

T h e c r i t i c a l a n a l y s i s of a i r b o r n e p a l y n o m o r p h s

o b t a i n e d a t h e l g h t s of 1 5 m a n d 1.80m f r o m F e b r u a r y ,

1 9 9 3 t o J a n u a r y , 1994 h a s b e e n i n v e s t i g a t e d . T h r e e

s e a s o n s of v a r y i n g p o l l e n p r o d u c t i o n ( f l o w e r i n g s e a s o n s ) t

h a v e b e e n e s t a b l i s h e d , v i z :

( a ) Dry S e a s o n ( J a n u a r y t o A p r i l ) ;

(b) L a t e Dr-y S e a s o n - R a i n y S e a s o n (May t o

A u g u s t ) ;

( c ) L a t e R a i n y S e a s o n - E a r l y Dry S e a s o n / H a r m a t t a n

( S e p t e m b e r t o D e c e m b e r ) ,

T h e r e a r e more p o l l e n i n c i r c u l a t i o n a t 1 5 m , t h a n

a t 1,80m i n t h e a t m o s p h e r e . hose o f f u n g a l s p o r e s b

b e i n g more a t a lower l e v e l ( 1 . 8 0 m ) t h a n a t 15m. he

l a r g e number o f p o l l e n i n ' t h e a t m o s p h e r e d u r i n g t h e

l a t e r a i n y s e a s o n - e a r l y d r y s e a s o n / h a r m a t t a n i s

a t t r i b u t e d t o t h e h i g h p o l l e n o u t p u t b y s u c h p l a n t s

a s p o a c e a e , ~ l a e i s g u i n e e n s i s , C a s u a r i n a e q u i s e t i f o l i a ,

A l c h o r r l e a c o r d i f o l i a a n d ~ i l i c i a e x c e l s a w i t h p e a k s o f

f l o w e r i n g p e r i o d s w i t h i n t h i s s e a s o n . Moreso, t h e

h a r m a t t a n w i n d (November t o D e c e m b e r ) r e f l o a t s some

p o l l e n a n d s p o r e s p r e v i o u s l y s e d i r n e n t e d a s o b s e r v e d by

t h e h l y h dust p a r t i c l e s and diatoms ~ > r - e v a l c n t at t l l i s

p e r i o d .

T h e c o n c e n t r a t i o n o f p o l l e n a n d s p o r e s i n t h e

a t r n o s p h e r e i s g e n e r a l l y m o d u l a t e d by m e t e o r o l o g i c a l

f a c t o r s , s o u r c e l o c a t i o n , s i t e o f s a m p l i n g u n i t s a n d

s e a s o n a l i t y o f p o l l e n a n d s i J o r e p r o d u c t i o n . H i g h

r a i n f a l l a n d r e l a t i v e l y h i g h h u m i d i t y f a v o u r t h e

c o n c e n t r a t i o n o f f u n g a l s p o r e s ' a t a lower (1.80111)

a t m o s p h e r e t h a n a t 15m. w h i l e t h e y c a u s e a r e d u c t i o n

o f p o l l e n c o n c e n t r a t i o n i n t h e a t m o s p h e r e . T h e e f f e c t

0 0 o f t e m p e r a t u r e i s h i g h e s t a t a r a n g e o f 2 3 . 5 C t o 2 5 C.

~ o k e r w i n d s p e e d f a v o u r s t h e c o n c e n t r a t i o n o f p o l l e n

a n d s p o r e s i n t h e a t r n o s p h e r e a s r e p o r t e d by ~ a l l e j a ,

e t a 1 ( 1 9 9 3 ) . 'I-

T h e s t u d y o n core p r o f i l e ( a s w e l l a s t h e

a e r o s t u d y ) s h o w s t h a t P o a c e a e h a d b e e n v e r y p r o m i n e n t

t h r o u g h o u t t h e z o n e s i n a s soc ia t i o n w i t h A l c h o r n e a

c o r d i f o l i a , E l a e i s g u i n e e n s i s , M o r a c e a e pp. a n d

Cornbretaceae/Melastomataceae. T h e p e r s i s t e n c e o f t ' h 2 s e

p i o n e e r t a x a s h o w s t h a t t h e v e g e t a t i o n was a m o s a i c

of o p e n fo res t s a v a n n a w o o d l a n d . H o w e v e r , m i n o r b u t

n o t i c e a b l e c h a n g e s i n t h e v e g e t a t i o n of t h e area w a s

deduced from t h e P o l l e n d i a q r a m .

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I

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I

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b

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APPENDIX I Table 5: Individual fungal spores totals

counted at the two different heialrts

Fungal Spore

Ljkelg Genera.? Idcmt if l e d

Drechslora/Helminthosporium

~iqrospora

u s tilaao

Endophragmiella

Cladosporium - Johnson's grass smut

curvularia

Venturia

Pithomyces

Coprinus

Torula

Asperqi llus/~enicillum

Tetraploa

Gliomastix

Pleospora

BOTANICAL GARDEN

( 1 - 8 0 M )

Fungal Spore

s temuhvlium

xylaria

Be1 trania

r1owdery mildew

sporomiella

~ i c t v o s ~ o r i u m

Puccinia

Massaria

Cunninahamella

Moniliales - type

Cordana musae

Melanomma

BOTANICAL GARDEN

(1 .UOM)

APPENDIX 111

~ u n g a l S p o r e

Yyr e n o p h o r a

cordana - t y p e

Unidentified spores

TOTAL

-

BOTANICAL GARDEN (1-80M)

Rounded end became concave

Pithomyces - -. . - . -. . . . - - 1 1

attachment

Endophraqmiella . .-

( Ascospore) FI a. I X

and seam ent ana!y,s.i.s PV = Polar view EV = Equatorial view

Poaceae ( PV)

FIG* xv

Celt is (~h-naceae-EV Exine: Scabrate

FD'-XVII

Exine Re t i cuht e PV

Exine: Striute EV

Lannea welwitschii --.-.-- - - -- - --

Anucard iaceae FIG. Xxr I

Exine: Reticulate

EV

PV Exine : Reticulate

EV Exine: SCU brute

Ex ine : Reticulate

EV

Exine: Str ide

EV

Newbouldia lnevjs Borag inaceae

FIG. k;4,4/\i