2. REVIEW OF LITERATURE

Review of literature

Overview of lianas

Lianas are structural parasites (Stevens, 1987) relying on other plants for

support The smking difference between lianas and other structural parasites

(epiphytes and hemi-epiphytes) is that lianas remain rooted to the ground throughout

their lives (l'utz and Mooney, 1991).

Climbing plants are found in most climatic conditions and every type of

vegetation, but they are more abundant and diverse in the tropics (Richards, 1996).

Schenck (1 892-93) estimated that more than 90% of climbing species occur within the

tropics. Lianas are a conspicuous and characteristic life-form in tropical rainforest and

thelr high abundance is an important physiognomic feature differentiating tropical

from temperate forests.

Climbing plants evolved from a diverse array of taxa including the

Gymnospermae (Gnetaceae), Monocotyledonae (e.g. Arecaceae) and the

Dicotyledonae (e.g. Bignoniaceae). Approximately one-half of the families of

vascular plants contain climbing species (Schenck 1892). In some families nearly all

the species are climbers; Hippocrateaceae and V~taceae are familiar examples. Most

lianas are light demanding and are abundant in natural or anthropogenically disturbed

areas (Putz and Chai, 1987; Hegarty and Caballe, 1991; Schnitzer and Carson, 2001)

Lianas possess various climbing modes to ascend on their host, based on

which various classifications have been proposed (e.g. Danvin, 1867; Schenck, 1893;

PUG 1984). Putz (1984) recognized the following climbing modes: stem twinm,

branch twinm, root climbers, tendril climbers and scramblers. Thc scramblers of

Putz (1 984) were further divided into hmWthorn climbers and scramblers.

The stem hwners twine around their host as a result of circumnutation

The branch twiners clasp their hosts by thelr lateral branches

About 95% of twiners tnvariably wil to the nght. Dioscorea is a major exception

(Baillaud. 1957; 1962) in that some of its many specles twine to the left and some to

the right. At least 20 species have been reported to Mine unreliably in either direction.

4 The root climbers ascend wth the a d of adventitious mots. They can

ascend supports of any diameter or texture.

4 The tendnl climbers climb wth thln. sensiuve tendrils that are modified

leaves, inflorescence or branches (Gentry, 1985) Most tendrillar species

characterist~cally establ~sh In disturbed, sunny areas (Bews, 1925; Kelly,

1985) and their fol~agr expands In full sun.

The hooW thorn climbers attach themselves to the vegetation with either

backward po~nting spines or hooks that grow around their hosts.

The scramblers are least spec~alized cllmbing mode which merely lean on

their host plants.

Lima abundance and diversity vary considerably across sites (e.g.Gentry,

1991, Appanah el a l , 1993, Perez-Salic~p el al., 2001). The lianas constitute -25%

of woody stem density and species diversity in many tropical forests (Gentry, 1991;

Appanah et al., 1993). Liana abundance and diversity increase with decreasing

latitude (Gentry, 1991). as well as altitude (Balfow and Bond, 1993). Liana

abundance was controlled by several factors, namely seasonality of rainfall (Genq,

1991), soil fertility (Proctor el al., f983) and disturbance (Laurance et al., 2001).

Lianas impede tree growth by competing for growing space and cause

mechanical damage by smothering the host trees ( h u , 1984; Clark and Clark, 1990).

Lianas are abundant in logged forests and they hinder tree regeneration in managed

forests Hence. lianas are considered as nuisance by foresten. h u ef a l . (1984)

reported that trees wlth lianas suffer higher mortality rates than liana-free trees.

Further. ~t has been suggested that lianas ~nfluence forest dynam~cs by increasing tree

m o v e r rate (Phillips and Gentry, 1994).

Llanas play a prominent role m forest-w~de carbon sequestration. Heavy liana

lnfesrat~on inhibits nee regeneration (Appanah and Putz, 1984, Schnitzer er al., 2000;

Laurance er al., 2001) wh~ch reduces the amount of carbon that 1s sequestered in plant

biomass (Laurance er al., 1997; Chave er al. 2001.)

L~anas also play significant beneficial roles In the ecosystem, by reducing soil

eroslon and contr~bute substantially to annual leaf biomass (Ogawa el al., 1965;

Klinge and Rodrigues, 1973, Kato rr al., 1978, Putz. 1983) They connect tree crowns

by prov~ding intercanopy pathways used by the arboreal mmals (Montogomery and

Sunqulst, 1978) and are also important source of food for insects (Gentry, 1985) and

monkeys (Emmons and Gentry, 1983). Mammals, ranging from the African

Prosim~an Euorrcus eleganrulus (Charles-Domnique, 1977) and Amazonian pygmy

marmoset to the African elephants (Shsrt'1981) heavily depend on lianas for food.

Liana inventories

Lianas are often ignored in forest inventories due to their small stem diameter,

anomalous stem structure., rampant vegetative reproduction which render difficulty in

distinguishing ramets (vegetatively produced plants) from genets (sexually produced

plants) and often pre-empt to the forest canopy which renders their collection and

study difficult. Perhaps for these reasons lianas have been excluded in many forest

studies. As summarized by Jacobs (1976). " the ecology of lianas is virtually a blank".

Ecological studits on lianas have begun only in the recent past (Caballe. 1984; Putz,

1984, Appanah and Putz, 1984, Putz and Chai, 1987)

Liana inventones across continents revealed a w~de variation in terms of the

areal extent of the study, methods adopted and glrtwdiameter class considered (Table

1) These variations pose difficulty In comparing the results across sites and to come

up w~th generalizat~ons By and large, quantitat~ve inventories on lianas were

conducted at smaller scales 0.1 ha or below, except for a few large-scale inventories

(Campbell and Newbery, 1993, Makana er a1 1998; Kadavul and Parthasarathy,

1999a; Muthuramkumar and Pannasarathy, 2000, Padaki and Parthasarathy, 2000;

Chitt~babu and Parthasarathy, 2001; Laurance el al. 2001)

Various methods have been employed for ecological sampling of Innas.

(Gentry, 1986) implemented an 'exploded' quadrat method (several small transects,

set up end to end or separated by ca. 10-20m). This method is helpful to cover several

hab~tat types in the forest and can avoid the patches of slngle liana species that is

presumably derived from vegetative reproduction.

Putz (1984) sampled cylindrical volumes rather than horizontal areas of forest.

Each circular 1 00m2 plots had imaginary wall extending from the ground to above the

canopy. Castellanos er al. (1992) proposed a methodology to characterize three

Tabl

e I.O

vew

iew

of l

iana

inve

ntor

y in

vario

us co

ntin

ents.

(R-~

ange

and

'-mea

n pe

r site

; DlG

bh- D

lam

eted

Girt

h at

bre

ast h

eigh

t)

Loca

tion

Site

D

lGbh

A

rea

(ha)

D

ensit

y of

lian

as

Sp

ies

Basa

l are

a Re

fere

nce

(cm

) nc

hnes

s (m')

Eumpc

Euro

pean

lian

a di

vers

ity 2

European

sites

' ~2

sdbh

0

1 0-

jR (I

5)"'

0-lR

(0.5

)'"

Gen

tly (1

991)

. 'E

umpn

n #&a : A

llach

n Ld

K (W

en G

erm

any)

, Su

derh

acks

tedt

. (W

est G

erm

any)

North

Amer

ica

Nor

th A

mer

ican

lion

a 12

Nor

th A

mer

ican

site

s a 5&

G

I 1-

143 R

(26 9

)"'

I-

~6

~

(6 9)

'" G

entry

(199

1)'

diw

rsily

'N

oh

An

alu

. Ika

Nw

Ihw

csl

Brao

ch (

Mav

land

), T

po

Rm

we (oak wd. M

~rou

rl). T

yw~ Rn

mc

(chm

gl

ade,

Mw

un).

Bab

ler

Stat

e Pa

rk (

Mw

un),

Cul

we

hver

Sta

te P

ark

(Mar

owl),

Val

ley

Vuw

Glad

es (

M~J

sani

). ?

Ire

sues

of C

hum

la (M

exic

o), L

a T

uxtla

s (M

exic

o), l

ndw

Cav

e Sta

te P

ark

(Neb

&),

Burl

~ng T

rrt (

Virg

inia

).

Ccn

bd A

mer

ica

Cent

ral A

mer

ican

lim

5 C

entra

l Am

eric

an si

tesc

22

.5"

0.1

l I-7

5R (4

9.4)

'" 6-

37R (

22.6

)'"

-(199

1)*

dive

rsity

' C

emd

A&

u

&ex

C

um

Olu

mo (

Nlc

arng

ua), C

mo

El P

~cac

ho (N

tcan

gua)

,Cur

undu

(Pan

una)

, Mid

den

Facs

(P

anam

a). P

iplln

e Roa

d (P

anam

)

Pana

ma

Trop

ical

moi

st fo

rest

all

1 31

65

65

htz

(1 98

4)

~

~.

Costa

Ria

T

ro~

id

wet f

ores

t, La

Selv

a >l

odb"

12

.4

133

20

Lieb

enua

n et a

l. (19

%)

210"

1

15

7

dodbh

I 13

7

Tabl

e 1 c

ontd

.

Loca

tion

Slte

D

/Gbh

A

rea

(ha)

D

ens~

ty of

lian

as

Spec

~es

Bas

al area

Ref

mnc

e (c

m)

--

nihn

ess

(m2)

N

icar

agua

C

osig

uina

22

0

1 17

10

Nic

arag

ua

La F

lor

Nic

arag

ua

Mas

aya

Nic

arag

ua

Om

etep

e

Cos

ta R

lca

Palo

Ver

de

22 5

'" 0

1 42

17

Cos

ta R

lca

Sanl

a R

osa

22 5'"

0

1 77

21

- - - - - - - --

Sout

h A

mer

ica

Solu

h Am

errc

an li

ana

47 S

outh

Am

erlc

an si

tes '

22 5"

0

1 7.

122~

(59

3)m

2-

5oR

(25

O)m

G

eny

(199

1)'

dive

rrrm

--

- ---,

'So

rlh

Am

nirn

n rb

u A

nu)u

K~

xhu

clo

. CO~IC

~IYI

IArg

cnlln

a~ I'a

rqw

tl R

e) (

Arg

nt~n

a,, t

crm

nlu

(Rol

lv~a

).

lnca

huar

r (8

oln

l~l.

Mua

rnhu

IRm

llI.

Alto

dc

Mtr

ah

(('h

llcl.

Ilo

qtc

C \a

n M

dnm

(('h

rlcl

Pu)

ch~

c Na

l~w

al Pn

rk

(Ch

lk). Ba

jo C

allm

a ((

~lo

rnh

~a

~.R

oy

w

& la

Cbr

va ,C

olor

nbta

) C

rm E

spcj

o IC

nlom

hlal

. tar

atlo

ne\ &

cal

l (C

ulom

b~a)

. (iskr

aram

ha (C

'olu

mbb

al, l

a Pl

anad

a ~

l'olo

mbu

l. t t

nra

Mrh

rcnh

rp ((

ulo

mbl

a). I a

vo

w ~

Col

omb~

al.

Tutu

nend

o IC

nlnm

h~al

. Cap

can

(Lcu

ador

j, la

lun

%ha

(

Fc

d~

),

la

unnh

c ~

Ec

dr

r. Rlu

Pal

mqu

e N

o 1

~tc

ua

da

).

Klo

Pal

c~qu

c Nu

2 (l:

cusd

or).

I'mun

cla

(tcu

adtr

I. Sa

ul (F

rmch

(iul

anal

RII,

Ir)u

l-m

~ (Par

qua)

I. C

ab

ra d

r M

m

(Per

ul.C

mos

&

Am

Jtap

c (P

ml.

Ca

ha

('a

<hu

(Pm

l, le

naro

Ilm

cra(

Prt

u). l

ml~

ana(

Pcr

u). M

~rh

ana(

bula

nd. Pm

).

M~s

hann

ftshu

amw

Per

u). M

~sha

na lw

httc

rand.

Peru

). Sh

mna

mar

u (P

eru)

. Tam

booa

m (l

atm

t~c I P

m). T

ambo

mu

(hc

nt~

c 2. P

m)

Ta

mb

pm

(upl

and

I'cru

) T

rap

oto

(Pm

) L

mcr

rrrn

~n

~Prm

,. Ya

nam

ono I

(Pcr

ul.

Yw

mo

no

2

(Pm

). Y

uvm

ono

~ta

hu

un

m Pm

l, vo

n Il

um

h~

h

(Pm

l H

lohm

Kan

chlV

cnem

cla)

&a&

Il

chlr

rlV

mca

rla

l Cam N

cblin

a I (

~co

em

cli)

. Ccr

m N

eblz

na 2

(V

enem

la)

Ven

ezue

la

Ever

gree

n fo

rest

al

l 0.

12

3429

R

olla

(197

1)

Fren

ch G

uiw

Ev

ergr

een

tropi

cal r

ainf

ores

t Im

I

415

Be

eb

(198

1)

Col

ombi

a Ta

yron

a 52 sd

' 0

1 18

H

eybr

ock (

1984

)

Tab

le 1

, con

td.

Loc

at~o

n Si

te

DlG

hh

Are

a (h

a)

Den

s~ty

of ll

anas

Sp

ec~e

s B

asal

are

a R

efer

ence

(c

m)

nchn

ess

(m')

Peru

Y

anam

ono

>lo

dhh

I 26

17

M~s

hana

Coc

ha C

ashu

Cab

eza

de M

ono

Tam

bopa

ta a

lluv~

al

Tam

bopa

ta te

rrat

ime

Ven

ezue

la

Neb

lina

base

cam

p

Col

ombi

a B

qo C

alim

a

Bej

o C

alim

a

Baj

o C

alim

a

Baj

o C

alim

a

Para

guay

M

bgla

cayu

Para

guay

Ta

rum

a P

anw

av

Para

bel

14

I5

16

Gen

try (

I 988

)

i0

I3

13

3 Fa

bcr-

Lang

endo

en an

d G

entry

(1 99

1 2

-.

B

oliv

ia

Sant

a C

ruz

25db

h I

60

Kill

een

er a

/. (1

998)

Fren

ch G

uian

a A

RB

OC

EL e

xper

imen

tal p

lot >50cm

tall

FlR

y-tw

o 14

92

47

Torio

la e

f a1

(1 998)

IOm

x10m

.

-

-

Cen

tral

Am

azon

Z

d'

Slxt

y nl

ne

2759

0 La

uran

ce el

01. (

2001

)

Loca

tton

Slte

D

IGbh

A

rea

(ha)

D

ens~

ly of

ltan

as

Spec

lrs

Bas

al a

rea

Ref

eren

ce

(cm

) - -- .. -

nchn

ess

(m2)

C

entra

l Am

azon

Se

vent

y tw

o 40

0m'

t2&

2

88

1023

83

La

uran

ce el

a1 (

2001

)

- ..

East

ern

Bra

zilia

n >2

m ta

ll 0

3 78

G

envi

ng an

d Fa

rias (

2000

) A

maz

on

-

Ecua

dor

Yas

uni N

at~o

nal Pa

rk r

idge

al

l 0

2 31

8 96

N

abe-

Nie

lsen

(200

1)

s~d

e Ec

uado

r Y

asun

i Nat

iona

l Par

k nd

ge to

p al

l 0

2 28

8 86

Bol

tvia

-

Twen

ty f

our 9

00m

2 Z

dbh

216

24

71

flM

3

--

- . ..~.

(200

1 )

Afr

ica

Afir

can

liu

m dr

vers

rry

8 A

fric

an s

~te

s " 22

5db

h 63

-168

'(104

4)m

27

-47

R(4

0 3)'"

G

entry

(199

1)'

' Afr

fran

silt

s :

Ban

yong

(Cam

erou

nl. M

t Cam

erou

n (C

amer

oun)

. Kor

up N

atio

nal P

ark

(hcr

ou

n).

Nda

kan

~nun

datcd

(C

amen

un),

Mak

okou

No

I (G

atan

), M

akok

au N

o 2

(Gab

on).

Om

o fo

rest (

N~g

er~a

),

Pugu

For

est (

Tana

nla)

Gab

on

Ever

gree

n fo

rest

M

argi

ns

2jd

M

I 14

4

Med

ium

tall

?sd

bh

I

I28

Cah

alle

(198

4)

Mat

ure t

all

2jd

M

1 80

--. . . . -

- .-

Gab

on

Ever

gree

n fo

rest

zs

dbh

I 12

2

Cab

alle

(198

6)

Tabl

e I.

cont

d ~

.

--

Loca

tion

Site

D

IGbh

A

rea

(ha)

D

ens~

ty of It

anas

Sp

ec~e

s B

asal

are

a R

efer

ence

-

(cn~

) ric

hnes

s (m2)

lturi

fore

st

Moi

st tm

p~ca

l fo~

sl

(I) L

enda

I 22

dbh

3 16

1 M

akan

a el a

1 (1

998)

(11)

Edor

o I

a"b

h

3 71

8 pp

~~

Mad

agas

car

Mad

agas

car h

am

3 M

adag

asca

r sl

tes '

a sd

hh

0 1

107.

134~

(1 19

3)'"

3~

-4

3~

(3

6)m

G

entry

(199

1)'

dive

rsify

'M

adag

ucor

run

: Ank

araf

anlls

ka (M

adag

asca

r). N

or)

Man

gak

(Mad

agas

car)

. Per

mel

(Mad

agas

car)

Mad

agas

car

Trop

ical

dry

for

est,

Bez

a M

ahaf

aly

Res

erve

W

et s

oils

as

dhh

01

8

4 D

ry s

oils

asd

bh 01

26

5

Suss

man

and

Rak

otoz

afy

(199

4)

Out

of r

eser

ve

_- >2

s?_

-. 0 0

5 6

2

Asi

a A

sian

/lam

div

ersi

fy

11 A

s~an

slte

s ' Z2

5db

h 0

1 25

-1 1

7~

(7

2 09

)'"

1 I-5

sR (3

2 4)

m

Gen

try(

l991

)' 'A

sh

rb

: Na

duga

n~ (In

du),

Gen

r~ng

(Mal

ays~

a) ,Pas

oh (3

0. M

alay

rla),

Paw

h (4

0. M

alay

r~a)

. Ball

etc

(-New

G

ulnc

a),

Vanm

a (P

apw

New

Gui

nea)

, Bak

o (S

araw

ak).

Sem

engo

h (Sa

raw

ak).

Nan

jen

Shan

(T

a~w

n),

Ken

tlng

Natio

nal P

ark

flaw

an),

Khao

Yal

(lba

iland

)

--

Mal

uysi

a Sa

raw

nk

Dip

tero

carp

fore

st, G

unun

g M

ulu

Nat

iona

l Pa&

Dip

tern

carp

fore

st

?IdM

I

440

Proc

tor e

l a1

(198

3)

dimensional above ground occupation of lianas and vines to give better insight to the

differential space utilization by lianas, their growth and leaf canopy dynamics.

Gentry (1982) reported that lianas make up an average of ca20% of species

sampled in dry forest, moist forest and wet forest vegetation Liana diversity averaged

12 liana species per O.lha sample of dry forest and 25 specles in moist forest and 32

species in wet forests.

From the Appendix-l of Gentry (1991). I have scored out the quantitative data

on llanas L 2.5cm dbh of 0 Iha: it revealed that on a regional scale, liana density as

well as diversity were higher in African and Madagascar forests. followed by Asian,

American, Australian, tropical island and European forests (Table 1).

The mean density and diversity of lianas 22.5crn dbh In O.lha of African sites

were I04 indiv~duals and 40 species respectively The Madagascar site contained 119

liana lndiv~duals In 36 species. The mean dens~ty and diversity of lianas in Asian sites

were 72 ~ndiv~duals and 32 species respect~vely. In neouopics, South American

average of liana density and species nchness respect~vely were 59 and 25 species

(Table 1); The Central Amencan average was 49 indiv~duals and 23 species, Ghereas

the North American average was 27 indiv~duals and 7 species. Tropical Islands scored

a mean liana density and diversity of 20 individuals and 7 species respectively.

Schnitzer and Bongers (2002) remarked that liana abundance and diversity

increased proportionally with decreasing latitude at much faster rate than in other

major life-forms (e.g. trees, shrubs and herbs with notable exceptions such as

epiphytic plants). For example, Gentry (1991 - Table 1.2) reported that liana species

incrcasod five-fold from tempmate to lowland tropical forests. Thm was an a v w

tm-fold d i f f m c e in liana density betwan tcmperete and tropical lowland for~sts,

with a three-fold difference between the most liana-rich temperate forests and most

l i a n a - p r lowland tropical forests (Gentry, 1982).

Lima diversity as well as density decreased with increasing altitude. For

Instance, Lieberman er al , (1996) found greatest diversity and abundance of lianas

(2lOcm dbh) in less than 500m altitude when compared to >500 altitude.

Similarly. three sites of tropical evergreen forest in Agumbe. Western Ghats

(Padaki and Parthasarathy, 2000), two sites of seml-evergreen forest in Eastern Ghats

(Kadavul and Parthasarathy, 1999a) and four sites of tropical evergreen forest in

&tern Ghats which were inventoried for lianas 2 5cm gbh also exhibited such a

trend Incidentally, each of these lites is located along an altitudinal gradient. A

comparison of these sites revealed that density decreased with increasing altitude

except at 200111 altitude of Agumbe forest (Padalu and Parthasarathy, 2000). The

authors argued that h~gh liana abundance was due :o disturbance such as selective

logging. This supports the view that most lianas are light demanding and grow in

natural and man-made clearings. The species richness dropped up to 650111 and

peaked at 680m alt~tude of Vellimalai forest and then the diversity dropped with

increasing altitude of tropical evergreen forest of the Eastern Ghats (Table I).

The density of small climbers, which increased as altitude decreased, ranged

from <5 numbers pcr tree in the higher elevation forests to >30 climbers per trc+ on

the coastal plains (Balfour and Bond, 1993).

De Walt er al. (2000) examined the diversity and abundance of lianas dong a

forest chronoxquence at Barn Colorado Nature Monument. Their major findings

include: lianas were significantly more abundant and diverse in secondary forests (20

years and 40 years) than in older forests (70 years and 100 years and Old growth

forest). Further. the climbing guild. tendril climben decreased and stem twiners

~ncreased over stand age

Proctor er a1 (1983) reponed a greater abundance of lianas on alluvial soils.

They polnted out that inundat~on by nver water by several times per year might both

e ~ c h so11 and lead to an increase in treefall frequency

Laurance er a1 (2001) assessed the effects of forest fragmentation, treefall

disturbance, soil and stand attributes on liana community Their major results revealed

that soil properties did not sign~ficantly predict liana abundance, whereas tree

biomass, forest disturbance and distance horn forest edge significantly predicted the

liana abundance.

Gentry (1991) reported a w~de variat~on In l~ana abundance among various

forests and soil types, resulting in no strong trend in liana abundance with 'soil

fert~lity. Lima abundance was as much as four tlmes higher in some nutrient-rich sites

than some nutrient-poor soils, which lead Gentry to conclude that there was a very

slight tendency for greater liana density on richer soils.

All Amazonian sites mentioned by Gentry (1988) had much higher density of

larger (tlOcm dbh) lianas i.e. 14 to 24 individuals and 10 to 17 species ha". At Bajo

Calima, there were only 6-1 1 lians individuals (TlOcm dbh) and 3-6 species ha"

(Faber-Langendoen and Gently, 1991). Among Indian forests, for a near similar girth-

class (SOcm gbh), the liana density m g e d from 17 to 74 individuals and rhat of

species richness ranged from 5-10 species ha" (Parthamathy, 1999; Kadavul and

Pahwuathy , 1999b; 1999~; Chinibabu and Parthasarathy, 200 1).

Maintenance of liana species diversity and abundance

Small-scale forest d~sturbance such as treefall gaps. has been hypothesized to

maintam species divers~ty (Denslow. 1987. Hubbell et al.. 1999). Schnitzer and

Carson (2001) In their study on B m o Colorado Island, compared the density and

specles nchness of shade tolerant trees, pioneer trees and lianas between paired gap

and non-gap sites on both per area and per indiv~dual bases. The results demonstrated

that both pioneer tree and liana density and species richness, were significantly higher

In the gap than non-gap sltes, whereas there was no difference between gap and non-

gap areas for shade tolerant trees. These results revealed that gaps maintain liana

specles d~venity and that this effect is not merely a consequence of increased density.

Lianas respond to forest disturbance from natural factors, such as hurricane as

well as irom anthropogen~c, such as clear cutting and selective logging. Lianas are

more abundant in gaps due to their abil~ty to colomze and proliferate. Specifically,

lianas may become abundant In gaps because: 1) more than 90% of the adult lianas

that fall into the gaps survive mefalls (Put& 1984); 2) lianas are often abundant as

advanced regenerauon pnor to gap formation (Putz, 1984; Putz and Chai, 1987;

Schniaer and Carson 2001); 3) lianas recruit Into the gaps both from sced rain and

sced benk, 4) they can encroach the gaps from the surrounding intact forest and 5 )

lianas in the gaps can sprout prolifically, producing many new stems (Appanah and

Putz 1984).

Lima abundance and diversity wen influenced by altitudinal and latitudinal

gradients as well as by several abiotic factors, including rainfall, soil fertility and

disturbance, and successional stages of the forest. The extent of liana diversity and

denslty In a given area 1s thus an outcome of the complex interactions of these factors.

Tree-liana interactions

Investigations on tree-liana interactrons arc important to understand the

possible factors, which could facilitate or lnhlbit liana establ~shment and distribution

(Clark and Clark, 1990, Campbell and Newbery, 1993).

Lima abundance in forests accelerate tree mortality and hinder tree

regeneratlon and delay canopy redevelopment for years, even a decade or more (Putz,

1980, Schtutzer rr 0 1 , 2000) According to Schnitzer er a1 (2000) lianas appear to

stall and alter conventional gap phase regeneration by promoting pioneer tree density

and diversity and reducing non-pioneer tree density

L~anas ~nterfere w~th trees by competing for light, nutrients and water

(D~llenburg el a1 , 1993) as well as by causing mechanical damage and therefore it is

to a tree's advantage to avoid or shed lianas (Strong, 1977). Fast growing tmes have a

better chance of avoiding lianas than slow growing trees (Putz, 1980).

Some trees have more lianas than expected by chance, thus they arc inherently

susceptible to lianas and the first liana in a tree provides support for other lianas to

invade the tree and increase its susceptibility to lianas (Putz and Chai, 1987).

The height of the lower branches of a tree canopy determines the d c r a b i l i t y

of a m e to climber invasion. In folwts where the canopy is high and there Ue few

hclliws more, climbers would enter the canopy of their host aecs horizontally from

neighbonng trees than in forests where the tree canopies arc low and more trellises arc

available (Balfour and Bond. 1993).

Gerwing and Farlas (2000) observed that liana abundance was inversely

correlated wth forest stature Low-stature forest had five times the density and three

tlmes the basal area of climbing stems as compared to high stature forest.

Studies of liana dlstnbutlon on trees have reported that the lower frequency of

lianas on certaln tree specles could be due to thelr architectural characteristics such as

hgh tree flexibility, long leaves and h~gh tree bole before the first limb (Boom and

Mori, 1982, Putz, 1984; Balfour and Bond, 1993; Campbell and Newbery, 1993).

Putz (1980) reported that smooth bark 1s select~vely advantageous to tropical

trees because it hinders trunk liana invas~on In contrast, 50% of the smooth bark

P e l t o ~ n c trees supported at least one liana (Nascimento et a1 1997), of course, in a

Peltogvne-nch forest.

Chalmers and Turner (1994) reported that climbing plants demonstrate a

preference towards particular support tree species. The suitability as a support may be

related to its leaf-size and density of foliage, as well as availability in terms of the

degree of branchng and the depth of its crown; but, Carse el d. (2000) reported a lack

of significant relationship between tree morphological baits and liana infestation.

Lianas are generally not distributed at random on their potential host tncs and

across forests. It is potentially as a result of facilitation process by which new

invading lianas use the stem of the fim established liana to reach the crown of the tree

( P i and Putz, 1994) and the spatial clumping of lianas in the forest cornsponds to

old light gaps (Caballe, 1986)

Climbing guilds

Liana climbing mechanisms change with respect to successional stages of the

forest. For instance, H e g q ( 1 988) reponed a strong polarization of tendrillar species

and bole-climbers to early and late succession, respectively Similarly, climbing guild

analysis along a chronosequence In a Central Panamanian lowland forest revealed that

stem twiners increased while tendril climbers decreased across stand age (De Walt er

a1 ,2000) Branch twlners did not show a significant trend.

Laurance et al. (2001) reported only lim~ted shift in climbing guilds from

forest Interior to disturbed edge All three major climbing guilds (branch-twiners,

manstem-twiners and tendril climbers) Increased In abundance near the edge; but the

proportion of each climbing guild remains nearly the same. Climbing mechanism

determines the maximum diameter support a liana can use. Tendril climbers an

restricted generally to supports with diameter <I0 cm and stem twiners to supports

<30cm (Putz, 1984; Putz and Chai, 1987). Branch twiners have higher maximum

support sizes (Putz, 1984; Putz and Chai, 1987). Thus the shrub and tree composition

of a forest stand will strongly influence the vertical and horizontal distribution of

lianas (Chalmers and Turner, 1994).

h t z (1980) has reported several anti-climbing defense of tries h m his

observations at B m Colorado Island which include rapid growth in diameter and

height. periodic shedding of branches and 1 or leaves, and steep branch angles.

Addit~onally, ants may prey on lianas invading their host mes. Trees, which have

evolved structures to attract ants, such as exuafloral nectaries, may bear fewer lianas.

Liana management

Lianas show detrimental effects on tree regeneration in managed and logged

forests. In such forests lianas are abundant and reduce the tree growth, increase tree

monallty and cause trees to bend. distorting the~r trunk and reduc~ng their timber

value (Pinard and PuK, 1994; Vidal et al. 1997). Hence, forest managers suggest that

penodic and pre-harvest liana cuttlng is a sensible method In forest management (Putz

er a/ 1984. Uhl, 1997, V~dal er 0 1 . 1997) Penodlc liana cunlng reduces the number

of l~anas In thelr crown (Perez-Sal~crup et al., 2001) and reduces the surrounding tree

damage, and further they reduce 50% of the post harvest canopy gaps (Fox, 1968,

Appanah and Putz. 1984)

Tl~e recent stud~es on liana cutting for forest management emphasize that

lianas can be removed only from the trees which have a high density of lianas in&eu

crown, to reduce the expense of liana cutting (Appanah and Putz, 1984, Vidal er a/.,

1997; Parren and Bongers, 2001) and to maintan arboreal animals that depend on

lianas for their food (Emmons and Gentry, 1983). Overall, liana cutting still appears

to be the most ecolo@cally sound and cost-effective strategy for forest management,

when done selectively on a tree to tree basis.