ffi cARoLE r. cuY

A SEASONAL INVESTIGATION OF NONSTRUCTURAL

CARBOHYDRATES IN SUBMERGED MACROPHYTES OF

SHOAL LAKE TN RELATION TO WATER DEPTH

ffi cARoLE r. cuY

BY

A THESIS PRESENTED TO THE FACULTY OF GRADUATE

STUDIES OF THE UNIVERS]TY OF MANITOBA

IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR

THE DEGREE OF

MASTER OF SCIENCE

DEPARTMENT OF BOTANY

MARCH, l98B

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rsBN 0-3L 5-47957 -4

A SEASONAL INVESTIGATION OF

IN SUBI'{ERGED I"fACROPHYTES

BY

CAROLE J. GUY

A tlresis st¡brlitterj to thc Facrrlty of cradrate stt¡dies oftlle U¡liVe rsity of Nlanitoba ill partial fulfilllnellt of the req¡ire¡lerìtsof tlie degree of

NON- STRUCTURAL CARBOHYDRATES

TO WATER DEPTH

OF SHOAL LAKE IN RELATION

MASTER OF SCIENCE

o 1988

Perriss.ior has beer gra,red ro rhe LIBRARy oF THE uNIVER-slrY oF i\'lANlroBA ¡o rerd or seil copìes of trris rhesís. rotlie NATIoNAL LItsRARY oF cANADA ro nricrofirnr trristhesis ard ro lerd or sell copies or'the film, and uNIVERSITylvllCROFILlvf S ro publish an absrracr of this thesis.

The author rescrves otlrer pubricatio¡r rights, a¡ld .eitrrer tlrethesis nor extcrsive extracts rro¡. it nray be prirrtecr or other-wise reproduced withor¡t the autllor's written Der¡nissio'.

ACKNOI{LEDGMENTS

Sincere appreciation is expressed to Dr. E. Pip,

whose dedication and guidance made this study possible.

A thank you is given to Dr. S. Badour, Dy. R. Hil1, and

Dr. G. Robinson for their interest and assisLance. The

efforts of Stephen Hanks, David Henry, and Robert Guy are

also appreciated. Financial support from NSERC postgraduate

scholarships is gratefully acknowledqed.

ABSTRACT

INTRODUCTÏON

STTE AND SPECIES DESCRIPTION

MATERIALS AND METHODS

1

TÀBLE OF CONTENTS

RESULTS

A. Total Soluble Carbohydrate

Starch

Total nonstructural Carbohydrate

Individual Soluble Sugars

Effect of Environmental Variables

õ

D.

d,.

b.

DI SCUSS I ON

APPENDICES

REFERENCES

Correlation analysis

Stepwise regression

Principal components

11

19

65

108

L37

245

247

249

276

291

308

ÀBSTRACT

Nonstructural carbohydrate content r+as examined in

Ceratophvllum demersum L., Elodea

Mvriophyllum exalbescens Fern. , Na'iaq

Rost,k. & Schmidt, Potamogeton f o1Íosus

E. praelonqus Wulfen, P. richardsonii

binsi i Oakes,

and sites in Shoal Lake. Species

t1

maximum in total soluble carbohydrate content during the

growing season. Starch and proportions of individuat sugars

also shor+ed seasonal variation. Sucrose was the predominant

sugar in most species. C. demersum was unique in being the

only macrophyte containing melibiose, raffinose, and stachy-

ose. Roots contained significant,ly more soluble carbohy-

and P. zosteriformis

canadensis Michx.,

drate than shoots and leaves in

frexilis (wi11d. )

centrations generally exceeded levels of soluble carbohy-

drate. All carbohydrate variables l¿ere neqatively correlat-

ed r,¡ith water depth in C. demersum, E. canadensis, and

B. foliosus. Starch was significantly negatively correlated

with time in C. demersum and marginally positively correlat-

ed with t,ime in P. zosteriformis. Stepwise multiple regres-

sion identified time and pH as significant factors in rela-

t,ionship to carbohydrate content in some species. The first,

principal component for total soluble carbohydrate in 5

species rras significant,ly correlated wit,h liqht and depth.

Raf . , P. graminbus L. ,

(genn. ) Rydb., P. rob-

Fern. at various depths

tended to show a seasonal

U. exalbescens. Starch con-

INTRODUCTION

Although the exist,ing literature on nonstructural car-

bohydrates in vascular plants is ext,ensive, information is

largely restricted to terrestrial organisms and litt,le is

known regarding the dist,ribut,ion and abundance of carbohy-

drates in submerged aquatic macrophytes. Much of the re-

search in this area has taken place within the past decade

and has produced useful yet sometimes inconsistent findings.

Carbohydrate reserves play a crucial role in plants,

enabling the conservation of energy and survival during

adverse conditions. Several studies have demonstrated siq-

nificant seasonal patterns in carbohydrate content of sub-

merged macrophytes (pip a Stewart I976, Best 1977, Shah &

Abbas I978, Titus & Adams 7979, Janauer 1982a, Best & Visser

i9B7). Other workers (eoyd I97O, Best I976, Muztar et a1.

I979) assumed that soluble carbohydrate levels do not fluc-

tuate in a given species during the course of t,he year, while

some evidence sugqests that, carbohydrate content may fluctu-

ate in a species but not show distinct seasonal dependency

(Best 7977).

Seasonal changes in the proportions of total soluble

carbohydrate, soluble sugars and starch may provide informa-

tion about patterns of carbohydrate ut,ilization and storage

in macrophytes. The proportion of sugars in several species

varies seasonally (e.9. Pip & Stewart I976, Janauer 1981a,

Best & Dassen 1987), and the changing proportions of reduc-

ing and non-reducing sugars have been viewed as an indication

of carbohydrate transport and metabolism in some aquat,ics

(Janauer 1981a, 1981b; Best & Dassen 1987, Best & Visser

1987). The distribution of soluble carbohydrate and starch

in different planL organs has also been examined (Tit,us &

Adams I979, ,Janauer 1981b , L9B2b¡ Janauer & Englmaier 1986,

Best & Dassen 1987) and shows t,hat not only roots and rhi-

zomes serve as storage areas.

St,udies indicat,e that sotuble carbohydrate is the pre-

dominant reserve substance in many submerged species (eest,

7977, Janauer 1981a, 1981b, I9BZa, I9B2b; Best & Dassen

I9B7), with at least one species lacking starch entirely

(Janauer & Englmaier 1986). Starch has been found as the

major reserve carbohydrate in a fewer number of species (Best

& Dassen 1987, Best & Visser I9B7).

Carbohydrate cont,ent has been used to measure t,he com-

petitive advantage of roots in an aquatic macrophyt,e (Best,

I977 ) and carbohydrate storage has been hypot,hesized as giv-

ing competitive advantage to a species ¡+ith a short growing

season (fitus & Adams I979). Interspecific differences in

total carbohydrat,e of macrophytes have been reported (e.9.

Shah & Abbas 1978, Janauer 1982b).

A strong relationship between water depth and the

chlorophyll:so1uble carbohydrate rat,io has been found for

some submerged species (Pip & Sutherland-Guy 1.987), sug-

gesting that photosynthesis Lras less efficienù at lower light

intensities and changes in spectral guality associated with

greater depth. Emersion has been shown to have a marked

3

effect on carbohydrate levels of one submergied species, with

emergent plants having much higher carbohydrate content than

submerged plants (Janauer 1986). Light conditions and COZ

avaitability were suggested to be the primary factors influ-

encing carbohydrate levels in this macrophyt,e.

Soluble carbohydrate may be an important parameter for

indicating trophic stat,us of lake water. Janauer (lg7g,

1981b) found a positive relationship between sucrose content

of macrophytes and inorganic phosphorous and nitrate concen-

trations in rrrater bodies. starch content was also reported

to vary with nutrient, st,atus of lake water (Janauer 1981b).

The importance of soluble carbohydrate as a trophic ind.icator

has been implied in reports of variations in carbohydrate

content of plants growing at the same water depth in differ-

ent locations (Muzt,ar et al. 7979, Titus & Adams 1979, pip &

Sutherland-Guy I9B7).

The object,ive of t,he present study was to examine in

greater detail the seasonal fluctuation pattern of starch,

total soluble carbohydrat,e and proport,ions of individual

sugars in Ceratophyllum demersum L., Elodea canadensis

Michx., Uy:j_Sphyf .L!$ exalbescens Fern., Najas f lexilis

(Wj.11d. ) Rost,k. & Schmidt, Potamogeton f oliosus Raf . ,

P. gramineus L. I P. praelongus Wulfen, P. richardsonii

(Benn. ) Rydb., P. robbinsii Oal<es, and !. zosteriformis Fern.

Superimposed on the seasonal pattern was an investigation of

horizonLal and vertical differences.

4

SITE ÀND SPECTES DESCRTPTION

All plant material rr¡as collected from Shoal Lake, situ-

ated on the Manitoba - Ontario boundary (49036' - 40'N,

95004'- 12'W) in a basin of Early precambrian bedrock.

The mean water level elevation is 323 m above sea level.

Sampling stations, rr¡ith the exception of the I2-I4 m site,

were located on Indian Bay, which has a surface area ofô

27.7 km", excluding islands. The bott,om of the bay is ir-

reg:ular, with a maximum depth of 10 m, and a mean depth of

less than 3.5 m. The bottom sediment,s of fndian Bay gualify

as gyttya, containing 5 to 39 % organic matter by dry weight.

Water chemistry showed variation throughout the study

area at different locations depths and times. During 1984-

85, the follor.¡ing parameter ranges were recorded within

Indian Bay: pH 6.9-9.1, total dissolved solids 4O-I23 mg/I,

total alkatinit,y 44-92 mg/t CaCOr, motybdenum reactive phos-

phorus 0.01-1.66 mg/L, nitrate-N 0.04-1 mg/I, nitrite-N

O-7 vg/I, ammonia-N 0=O.25 ng/t, chloride 0 mg/t, sulphate

O.4-4 ng/I

Thermal stratification was generally minimal or absent

in the study area because of the large surface area and ex-

posure of the lake. Localized thermoclines ïrere present only

at some stations and r,rere of limited duration. Maximum tem-

perature recorded at 72-74 m was 17-19oC in 1985, with maxi-

mum surface temperatures ranging from 2I-234C.

Midday surface incident, values of photosynthetically

active radiation (pen) ranged from 0.1 Lo 2.4 mE s-1 ^-2,

5

depending on amount of cloud cover (Appendix B). Light

attenuation varied at any given time at different stations,

with the best water clarity at the 72-14 m site. Light

intensities at this location at 13-14 m were estimated at

0.5 to I.0 % of surface incident PAR (Appendix C).

Some macrophytes showed defined vertical zonation, but

6 species could sti11 grow in persistent communities as deep

as 14 m (Appendix E). The minimum light intensities avait-

able at the respective maximum depths for the different spe-

cies in Appendix E are early May values, aL the sites with

the greatest, liqht attenuation where each species hras record-

ed. Generally only Potamogeton praelonsus attained the sur-

face during the season, even in shallower water. Aside from

this species which achieved shoot lengths of 4 m by mid-June,

the tallest, of the remaining submerged species r¿as P. zos-

t,eriformis, wit,h maximum shoot lengths of 2 m.

Substantial macrophyte growt,h had already taken place

even before the ice broke up in the spring. By mid-July,

above-qround macrophyte biomass for fndian Bay had a mean

value of I9O g/mz in 1985. During mid-May to mid-Ju1y the

macrophyte biomass appeared to double every 4 rr¡eeks. During

t,his time temperature in the study area increased from an

average of 13 C in mid-May to 16 C in mid-June, Lo 20 C in

mid-July. The biomass of individual macrophytes in mid-

July of 1985 is shor,¡n in Appendix F.

o

MÀTERTAI,S ÀND }'fETHODS

The mat,erial used in t,his study vas collected at 7 Lo

24 stations in shoal Lake (Fig. 1 ) 9 times during t,he 1985

qror+ing season as part of an ongoing study conducted by

Dr. E. Pip of the limnology of the lake. plants l¡ere ob-

tained by scuBÀ and dredging with a rake at depths ranging

from 1 to 14 metres. The plants were washed at the collectionsite to remove as much periphyton as possibte and packed inplastic bags on ice in darkness. plant tissue was frozenr^¡ithin 7 hours of collect,ion and subsequently f reeze-dried.

Green stems and leaves for each species were combined to give

a composite sample from a number of different plants for each

t'ime and location. shoots were al1 less than 1 m in length.

Roots , Thizomes t ot seedsr p.fêsêDt in some species, '\¡rere also

examined when available.

Plant samples 'hlere cut r¿ith scissors into sma1l segments

and sub-samples of 0.1 to 0.5 g were homogenized in a mortar

with 25 ml of B0% ethanol. A replicate extraction was made

f or samples of suf f icient size. The homogenate \^ras centri-

fuged at 300 x g at 0 C for 5 minutes. The volume of t,he

supernatant rras made up to 30 mt with B0% ethanol. À 25 ml

sample of the crude extract r^ras air-dried at room temperature

and stored at 5 c until used later for chromatographic separ-

ation and quantification of individuar sugars. The remaining

5 ml of extract was analyzed for total soluble carbohydrate

using the anthrone method of Roe (i955). Absorbance for

3 aliquots !¡as measured at 620 nm in a Beckman Du-7 or a

Fig. 1 . LocationShoal Lake during

of sampling stations in1985.

,r t" I rofrr¡o.:-o ..

.

-- ---+ ---:- - qS

---*' --f"¡ !- l"/

t¡-1 ,

Ç.

- r- I1A9. .. l-:$'rc

¿

rì1-3 '\i

1-iFi)F'

¿

r,!-.oL' È.-' ':r?

=nQu-' -i

t.

vv

9

Pye-Unicam spectrophotometer. A catibrat,ion curve was

constructed for each spectrophotometer for glucose concen-

trations ranging from 0 to 200 ug / mJ-. Linear regression

equations for these standard curves were calculated (r<0.99,

P<0.001 , n=10) :

Beckman: gtucose (ug,/ml ) = (Aøzo - 0.000468) /O .00499Pye-Unicam: glucose(ug,/ml) = (oOZO + 0.00599)/0.00498

All soluble carbohydrate values Ì¡ere expressed as equivalent

glucose units.

The crude plant, exùract was purified by using 2 suc-

cessive sets of ion exchange columns, in a method modified

f rom that of Vfang(1960). Dowex 50W, a cation exchange

resin, and Dowex -L, an anion exchange resin, lrere used,

each with a mesh size of 200 - 400. Each resin was mixed

l¡ith distilled water and transferred several times betr¡een

2 beakers to remove heavier particles. The mixture was

allowed to settle and the supernatant decant,ed to remove

smaller particles. The process of settling and decanting

lras repeated several times. fmpurities r¡ere removed by

boiling the resins in 2N HCI for 5 minutes and discarding

the supernatant. Dowex 50W r,¡as then washed with distilled

water until the pH of the eluent stabilized. Dowex -1 lras

placed in a 4.5 x 50 cm glass column and washed with lN

dodium formate until chloride ions could no longer be

precipitated in the eluent by adding a solution of AøNO'.

A volume of 110 ml of 0.lN formic acid was passed through

the column and the resin was washed with distilled water

i0

until the pH of the eluent st,abilized. The resins were

poured int,o 1 x 15 cm qlass columns plugged wit,h glass wool.

Eleven columns Ïrere run for each of the respective resins.

The dried crude extract from the oriqinal volume of

25 mI l¡¡as dissolved in 2 mL of B0% ethanol and applied to

the Dowex 50!ri columns. The solution was eluted with 100 mr

of distilled water to remove soluble sugars and organic

acids, giving Fraction i (Fí9. 2). The resin from the set

of 11 columns 'r4ias placed in a beaker and washed with 1 1

of 4M NH4OH to remove amino acids (Fraction 2). The resin

\,¡as recycled by washing wit,h distilled r+ater until pH was

stable. Fraction 1 was air-dried at room temperature and

dissolved in 2.0 ml of B0% ehtanol. Each sample was applied

to a Dowex -1 column and eluted vith 100 m1 of distilled

water to give Fraction 3 containing soluble sugars. The

eluent was air-dried at room temperature. The Dowex -1

from the columns was placed in a 4.5 x 50 cm column and

washed with 800 ml of 4N formic acid and 200 ml of 6N HCI

to remove organic acids (Fraction 4). The Dorr¡ex -1 resin

was recycled by successive washes of sodium formate, formic

acid, and distilled rsater as bef ore. Part of t.he 2 resins

r^¡as removed and discarded aft,er use, and volume hras replen-

ished with resin prepared as described above. The resins

tlere completely replaced after every 3 runs.

Sugars present in Fraction 3 were isolated by using

descending paper chromatography as described by Pip and

Stewart (1976). Four sheets were run simultaneously in a

t1

Fig. 2 . Procedure forof crude plant

purificat,ionextract.

I2

ACT

E RESIN

EXTR

IHANG

CRUDE

CATION EXC

n---^!-- ¡f | ¡tur. ¡u¡t .torganic acids

ANION

f-^-^: ^- aI tauIluil Jsugars

IItIv

PAPER CHROMAT

isolationidentificat iqu antificati

OGRAPHY

onon

13

52213:35 mixture of butanol, acetic acid, and water (putman,

7957 ) ror 42 lnr. Six replicates were run for each samÞl_e.

sugars were visualized by developing alternate lanes

on each chromatogiram in aniline diphenytamine phosphate inacetone and oven-heating at approximately 100 c, as de-

scribed by Bacon and Dickinson (1957) and smith (1960).

Regions of undeveloped strips corresponding to spots on

the developed lanes were eluted separately in 5.0 m1 of

70% isopropanol, air-dried, and redissolved in 1.0 m1 ofro% isopropanol. The guantit,y of different suqars was de-

termined using t,he anthrone method (Roe, 1955).

Developed spots were identified by comparing to colorreactions and R values, relative to fructose, of arabinose,

fructose, galactose, glucose, lactose, maltose, melibiose,

myo-inositol, raffinose, stachyose, sucrose, trehalose

and xylose standards. Four sugars found in ceratophyllum

demersum samples hrere further analyzed with NMR speetroscopy.

These vrere compared to standards of lactose, melibiose,

raffinose, myo-inosit,o1, melezitose and stachyose.. Sample

sugars were prepared by pooling eluted spots from several

chromatograms. Each of t,he 4 pooled samples was filtered

and evaporated to obt,ain a total dry weight of 2 - 3 mg.

The dry sugars l{ere dissolved in 0.5 ml of B0% et,hanol and

filtered by passing through a pasteur pipette containing

a glass wool p1ug. The solutions lrere freeze-dried and

redissolved in 0.5 ml of DZO and placed in NMR tubes.

Standard sugars were prepared by dissolving 3 mg of each

l4

sugar in 0.5 ml of DZo. Proton and 13c trptR spectra were

prepared at 300 and 75.47 M}:,z respect,ively, using the

spectrograph at the University of Manitoba Chemistry Depart-

ment.

Starch content rr/as determined by a modif ication of

a method from McCready et, at. (1950), as summarized in

Fiq. 3. Plant, tissue was ground to flour using a mortar

and pestle. A sample ranging f rom 0.07 to O.20 g r^ras mixed

with a few drops of B0% ethanol and 5.0 ml of distilled

water in a centrifuge tube. Twenty ml of hot (60-65 C)

ethanol kras added and t,he solution was centrifuged at 9770

x g for 7 minut,es at room temperature. The supernatant

was decanted and the residue l^ras given 3 additional washes

with 20 ml volumes of hot B0% ethanol . A fift,h wash was

performed on selected samples in order to measure any sol-

uble carbohydrate remaining in the residue. The soluble

carbohydrate removed in each wash was quantified by the

anthrone test. Correction factors were calculated for each

species to account for soluble carbohydrate remaining in

the residue after the 4 alcohol washes; thus preventing

overestÍmation of starch.

After the final centrifugation, 1.0 ml of water ruas

added to the residue and the mixture r+as transferred to

a 15 ml glass centrifuge tube. Starch in the residue r.+as

solubilized by adding 1.3 ml of 52% perchloric acid and

stirring for 20 minutes. Five ml of water î¡as used Lo rinse

the original centrifuge tube and was added to the perchloric

15

Fig. 3 Procedureof starchtissue.

for determinationcontent of macrophyte

l6

IS SUEDRY GROUND T

II

IC HOT ALCO

WASHESHOL

SOLUBLESUGARS

DETERMINATIONSTARCH

RESIDUE

II

ISTARCH

SOLUBILIZATION

AQUEOUSSTARCH

SOLUTION

AQUEOUS. STARCH

ION-"*SOLUTION

RESIDUE

II

JSTARCH

SOLUBILIZAT

acid mixture. This volume

for 5 minutes in a clinicalsolution was decanted into a

remaining in the residue was

perchloric acid and water.

bined and brouqht to a totalwater.

The starch solution was

L7

lras centrifuged at medium speed

centrifuge. The agueous starch

graduated cylinder and starch

solubilized as before with

The two supernatants Ì,¡ere åo*-

volume of 20 ml with distitted

t,hen filtered and diluted with

distilled water to contain 20 to 80 micrograms of starch

per m1. This was accomplished by diluting 1.0 mt of solu-

t,ion to 2A to 40 nl. One ml of the dilute sotution was

cooled in a test tube in a 25 C r*ater bath and 2.0 mt of

anthrone reagent r'rere added. samples were mixed r+ell, r+hi1e

maintained at 25 c, and were heated for 7.5 minutes at loo c.

The tubes were immediat,ely placed in a 25 C çater bath and

the absorbance v'as read at 630 nm on a Beckman Du-7 spectro-photometer. The blank was a mixture of water, perchloric

acid and anthrone reagent. A standard curve lras constructed

for 0 to 80 micrograms of glucose per ml. The corresponding

regression equation was calculat,ed (r<0.99, p<0.001, n=10):

glucose(ug,/ml) = (AO¡O + o.OZ97)/0.0168

Glucose found was multiplied by 0.90 to convert to starch(McCready et al. 1950).

The single extraction method for soluble carbohydrate

and t,he extraction vith successive hot, alcohol washes r,rere

compared using representat,ive samples for each species from

various locations and t,imes of collection. The method

involving the series of hot alcohol r+ashes gave consistently

higher values than the cold alcohol met,hod with one wash.

Appropriate correction factors lrere calculated for each

species to account for underestimat,ion of soluble carbohv-

drate in the singte extraction method.

standard sugar solutions ïrere prepared to approximate

the sugar content and composition of the crude sample ex-

tracts. volumes representing a 10 to 40 mg range in t,otal

carbohydrate were passed through the 2 set,s of ion exchange

columns in the method previously described. Sugars r¡rere

isolated as before by descending paper chromatography and

were guantified by the anthrone method. correct,ion factors

tÕ

based on percent recovery were calculated for each of the

sugars and h¡ere applied to data obtained for all of the

unknowns.

Statistical tests were

the SAS statist,ical package

carried out in this study using

at the University of Manitoba.

REST]LTS

À. Total soluble carbohydrate

comparison of the 2 extraction methods for solubr-e

carbohydrate showed that the cold alcohol extraction removed

47 .3 to 68.2 % of the soluble carbohydrate extracted in theseries of 4 hot alcohol washes (tabte 1 ) .

Total soluble carbohydrate content, of shoots and leaves,in terms of mg equivalent grucose per gr .h¡as guite variablefor most species during the 1gB5 growing season (tante 2).Mean seasonal values ranged from 38.i for Najas flexilis to87 .6 for Potamogeton richardsonii.

Total- soluble carbohydrate content of macrophytes atvarious depths and stations during the 1985 season is shown

in Figs. 4 to 13. Linear regression analysis for each sam-

pling time gave t,he foltowing significant negative correla-tions of solubte carbohydrate and dept,h: ee¡etA!þytlumdemersum on June 27 1R2=0.68, p<0.001, n=I2), Elodea

canadensis on July 1O-11 (n¿=O.67, p<0.01, n=I2), p. foliosus.)

on May 2 (n¿=0.3O, p<O.O2, n=18) and Ju.ty iO-11 (R2=0.56,

p<0.001, n=51), Mvriophyllum exalbescens on AugusL Zg

(R'=0.16, pcO.05, n=27), and p. zosteriformis on May 16

(R"=0.78, p<0.001, n=L2) . Negative retationships r,rith depth

that lacked significance due to lirnited depth representationïrere observed for P. zosteriformis on June 27 and AugusL zg.

Positive correlations between soluble carbohydrate and

rlenf.h \^rêrê fnrl¡d fOr C. demersum .ìn Mer¡ 2 (R2=0.35, pcO.OO1," ": uu¡rru! Ð q¡Lr vr¡ r.rqJ

n=30) and May i6 (R¿=O.22, p<0.005, n=36), and M. exalbescens

19

20

)on May 16 (R'=0.23, p(0.05, n=18). Positive correlationswere also observed for E. canadensis on May 2 and for p.

f oliosus on August B, although t,hese .$/ere not signif icant.sample size for N. flexilis, p. gramineus, p. Þraerongus,

P. richardsonii , and p. robbinsii Lras smal1 and vertical_ re-lat,ionships could not be examined.

Mean carbohydrate content for each species and sampling

date were analyzed for differences in sNK and Tukey's tests(Tab1e 3). carbohydrate 1evels in different plant organs

r.rere also compared (ta¡te 4). Levels of soluble carbohydrate

showed 1iùt1e seasonal fluctuation during 1gB5 in c. demersum.

The mean value for the July sampling time was significantryhigher than that of the other sampting dates. E_. canadensis

also shor+ed a seasonal peak in carbohydrate content, wit,h t.he

mean level for August B significantly exceeding levels on allother sampling dates. The July io-11 mean lrras signif icant,lyhigher than the May, June 13, and August 29 sampling t,imes.

The soluble carbohydrate content of stems and leaves r¡ras not

signi-ficantly different, from the l-evel in roots, for the one

sample on May 30 where roots \iere available.

Soluble carbohydrate content for M. gxelþe-çç.en-e was

sÍgnificantly higher on April 27, May Z, and May 16 than on

June 2J, July i0-11, and August 29. The carbohydrate con-

tent of roots was sig-nificantly higher than that of leaves

and stems, in the 5 samples where rootb \{ere represent.ed.

Differences between the 2 categ,ories of plant organs ranged

from 10 to 40 mq/q.

Table 1. Proportion of soluble carbohydrateextracted in cold alcohol met,hod, rêlative tothe quantity removed by successive hot alcoholwashes.

Spec i es

2I

Myriophyl lurn exaLbescens

Po tamoge t on guê-r-i-ne!s

P. robbinsii

Najas flexilis

Ceratophyllum demersum

Elodea canadensis

Potamogeton praelongus

!. foliosus

3. richardsonii

3. zosteriformis

Þa roon fv / . ^-

\{ +\ts: IPonnr¡arrr \:--" /

6B

67

56

55

53

51

50

47

2(2

0(3'l l?

3(J

o(2

R/q

2(z

1(2

3(4

otz

1)

2)

6)

0)

1)

0)

4)

4)

0)

ol

Table 2. Overall seasonal soluble carbohydrat,e contentof macrophytes during the 1985 season. N represents themany of which 'brere examined in replicate.

Species

Potamogeton richardsoni iP . tol- 10sus

P. p*raelongus

P. zg_s_lcrif-or:n:E

P. gramineusMyriophy 1 1 un er(3 lÞCE_qCnÊ

ee-r a þ op.Ày r.L:r¡n d.emeË Êum

P_p_tamqge t on r=sþhi nsjjElodea canadensi€N_a-.iè€ fl-exilis

CarbohydrateRange

71.920 .944.O23 .4?Aq

20 .431.1)a^

20 .232 .8

07 '7

r37100

110

84. B

86.675.555. B

91. B

Mean

(mq equiv glucose q-1 )number of samples,

Bt .67r.77r.363.659.753.045. 5

43 .84r.o38. 1

I tôñf h

Range (m)

5

32

3

22

4

25

38

6

L4

3

1.5 - 2

1 - 6.5

MeanDepth (m)

2-2-1-1-1-1-1-

I43

13

5

1AIq

1R

5.02.O

4.62.7)'7

3.92.64.47.4

N)t\)

23

P. foliosus also showed statistically significant re-

lationships in soluble carbohydrate content, with a seasonal

maximum observed on May 30 and June 1 3. There Ì¡as no con-

sistent relationship between carbohydrate levels in roots

and leve1s in stems and leaves, and means were not siqnifi-

cantly dÍf ferent for the 2 samples wit,h roots.

The soluble carbohydrate conLent of p. zosteriformis

showed an overall seasonal increase from May to July and a

decrease during the remainder of the season. The mean glu-

cose levels on June 27 and July 10-11 rllere signif icantly

higher t,han the mean levels for May and August dates. Roots

and rhizomes contained significantly less soluble carbohy-

drate than leaves and stems for the single sample where roots

were available.

The remaining macrophyte species lüere represented on a

fewer number of sampling dates and trends for the fult grow-

ing season could not be examined. P. richardsonii gave no

apparent pattern in soluble carbohydrate content over 3

dat,es, and levels in seeds and shoot.s/leaves were not siq-

nificantly different. Carbohydrate levels in P. praelongrus

were significantly higher on June 13 than on June 27. Con-

tent in seeds'hlas not significantly different from amounts

in shoots and leaves in the qnor.i aq p qramineus and

P. robbinsÍi yielded significant seasonal peaks in soluble

carbohydrate content on June 13 and July 10-11/ respect.ively.

Levels in N. flexilis were significantfy higher on AugusL 29

than on 2 earlier dates.

Seasonal soluble carbohydrate 1eve1s l/ere examined at

selected depths for C. demersum, M. exalbescens, P. foliosus,

and P. zosteriformis (Figs. 14 to I7). Carbohydrate content

in C. demersum remained relatively constant throughout the

season at 2 and 3.5 m, fluctuating between 40 and 50 mg/g.

Levels at 5 m varied more than at the shallol¿er depths, with

a maximum in July. Soluble carbohydrate 1evels of M. exal-

bescens over a depth range of 1 t,o 3.5 m tended to decrease

from early t,o mid-season. Soluble reserves increased from

mid-July to early August at 1.5 and 2 m, r+hile samptes from

2 and 3.5 m showed a decrease in carbohydrate at t,he end of

the season. Levels tended ùo be higher at 2 m than at I ,

1.5, and 3 m. Soluble carbohydrate content of P. foliosus

increased during the early part of the groving season (May 2

to June 13) for a depth range of 4 to 6 m. Samples from 4,

5, and 6 m shor+ed a decrease in total soluble susars from

June 13 to July 10-11. Levels tended to be higher at 4 m

than at 5 and 6 m. Carbohydrate in P. zosteriformis for 2,

3.5, and L2 to 14 m reached maximum values in mid-season

(June 27 or July 10-11) and declined sharply in August for

2 and 3.5 m samples. Values at 72 to 14 m were lower than

or similar to those at the shallower depths. Carbohydrate

1eve1s at 2 m exceeded levels at 3.5 m in July and August.

Macrophytes growing at the same depth in different 1o-

cations showed variation in soluble carbohydrate content dur-

ing the 1985 growing season (Tabl-e 5). Species represented

at stations 22 and 23 tended to have a hiqher soluble

21

carbohydrate content at station 22, riith differences being

signif icant for M. exalbescens and P. praelongus on .lune 27.

An exception to this trend lras observed in M. exalbescens

on August 29, when plants at station 22 had significantly

more soluble reserves. Differences observed between sites

showed some inconsistencies between species. Soluble carbo-

hydrate levels lrere significantly higher at site 1 than at

site 22 in q. demersum on May 2, while the reverse signifi-

cant relationship was observed in M. exalbescens. On June

13,C. demersum contained significantly more soluble carbo-

hydrate at station 2 Lhan at station 9. P. foliosus, in

contrast, had significantly higher levels at the tatter site.

Interspecific differences in mean soluble carbohydrate

content 'were observed for the various sampling dates alt,hough

trends were inconsistent (Table 6). Comparisons l¡ere made

using SNK and Tukey's tests (Appendixc ). The number of

species represented on the dates ranged from 2 on ApriL 27

to 10 on June 27.

E. canadensis contained less soluble carbohydrate than

all other species represented on May 2, May 16, May 30, June

13, and Augtust 29, and had the greatest number of significant

differences with other species on May 2 and AugusL 29. On

August B however, E. canadensis had significantly more solu-

ble sugars than 7 other species. On the same date, P. rob-

binsii had less carbohydrate than all other species, with 7

significant comparisons. E. foliosus had significantly more

soluble carbohydrate than M. exalbescens on April 21. This

25

26

species also exceeded all other species in soluble sugar

content on May 2, May 30, and June L3, wit,h some significant

comparisons. P. richardsonii and P. zosteriformis had a

higher carbohydrate level than other species on June 27 and

,Tuly 10-i 1 . On the latt,er date, these 2 species were signif -icantly different from all other species except from P.

sramineus and from each other. P. richardsonii had the

greatest number of significant differences with other species

on June 27. M. exalbescens and P. foliosus had significantly

more soluble carbohydrate than the 4 ot,her species present on

May 16.

27

Fig. 4. Total soluble carbohydrate content in stems

and leaves of Ceratophyllum demersum on various sam-

pling dates during the 1985 growing season. Vertical

bars represent standard error and numbers beside cir-

cles indicate sampling sites. Depth (in meters) for

each collection time is shown on the horizontal axis.

Statistically significant relaLionships between depth

and tot,a1 soluble carbohydrate content are shown for

May 2, May 76, and June 27 .

CEII^'I'OPIIYI,I,UM DEMERSUM

82æ EB"

{'"

{þn

&l'

_þrçß- N)

29

Fiq. 5. Tot,al solubte carbohydrate content in stems

and leaves (closed circles) and roots (open circles)

of Elodea

the 1985 growing season. Vertical bars represent stan-

dard error and numbers beside circles indicat,e sampling

sites. Depth (in meters) for each collection time is

shown on the horizontal axis. A statisticatly sig-

nificant relationship between dept,h and total soluble

carbohydrate content is shown for July 10-11.

canadensis on various sampling dates during

a) z F: z (¡ (¡

!\tG

EQ

Utv

cLU

cosE

c-l

SO

LUB

LE C

AR

ßO

IIYD

RA

TE

# re_-

{

F4l

-{ &N

t#

ts€H (,

l--@

)-{

3 I :- z F' õd

rõ (n

lt>

31



of Myriophytlum exalbescens on various sampling dates

during the 1985 growing season. vertical bars repre-

sent standard error and numbers beside circles indi-

cate sampling sites. Depth (in meters) for each col-

tection time is shown on the horizontal axis. statis-

t,ica11y significant relationships between depth and

total soluble carbohydrate are indicated for May 16

and Augusb 29.

MYBTOPHYLLUM EXALBESCENS

I(,Í¡J(n

e-¡

Ðof¡)

Ef¡¡Fú

oCE¡

ÉQf¡l.¡rqÐIo(n

Sr.

þ-þzs

Sr

1

AP 27 M2

o1

017 ftt

e23@3

9zz

o9"

$s 91

Qs

$s

@22

8,1

(¡.)

N)

923

p(.05

33

Fiq. 7. Tot,al soluble carbohydrate content in stems

and leaves of Naias flexilis at collection site 3

during the 1985 growing season. VerÈical bars repre-

sent standard error. Sampling dept'h (in meters) is

shown on the horizontal axis.

SOLURT,E CARBOI{YDRATEMG EQUIV GLUCOSE G-I

Þf\)(o

zC-r

U)

Ã-EFI

Xt-(t)

c!À

35

Fig. B. Total soluble carbohydrate content in stems


of Potamogeton foliosus on various sampling dates

during the 1985 groning season. Vertical bars repre-


cate sampling sites. Depth (in meters) for each col-

lection t,ime is shovn on the horizontal axis. Statis-

tically significant relationships betneen depth and

t,otal soluble carbohydrate content are shown for May 2

and July 10-11.

POTAMOGETON FOLIOSUS

A.

94

@e

{" {"?"'{"

{'

Ë,{e

{,,r{.

odtðnq6

$e{o

UJOì

37


and leaves of Potamogeton gramineus at collection site

22 during the 1985 growing season. Vertical bars re-

present standard error. Sampling depth (in meters) is

shown on the horizonLaL axis.

POTAMOGETON GRAM II{EUS

I

U)

UJ

¿

{,,

70

60

l;¡F

I

--lI

Ø

40

30

20

t,{"

JN13 JN27 JYlO-11 A8

39


and leaves (closed circles) and seeds (open circle) of

Potamoqeton praelongus at collection sites 22 and 23

during June of the 1985 growing season. Vertical bars

represent standard error. Sampling depth (in meters)

is shown on the horizontal axis.

POTAMOGETOhJ PRAELONGUS

40

{"Hgo(-)

=J

=80Ð

Ë¡tdL

UEr-J

Jv)

60

50

2

JN 27JN 13

4I

Fig. I 1 . Total soluble carbohydrate content in stems

and leaves (closed circles) and seeds (open circle) of

potamoseton richardsonii on various sampting dates

during the 1985 growing season. vertical bars repre-

sent standard error and numbers beside circles indicate

sampling sites. Depth (in meters) for each collection

time is shown on the horizonLal axis.

POTAMOGETON RICHARDSONII

A')

I

',¡¡,t)

U

=J

:lt¡

¿.

EIF

Ut=lJ

JU)

A8JY 10-11JN 27

Fig. 12. Total soluble carbohydrate content of stems

and leaves of Potamoqeton robbinsii on various sampling

dates during t,he 1985 growing season. Vertical bars

represent standard error and numbers beside circles

indicate sampling sites. Depth (in met,ers) for each

collection time is shown on the horizontal axis.

I

qU)

(J)J

:)ol:]

4

POTAMOGETON ROBBTNSIT

ç-

(J

r-ìI

IU)

{'

$.$'

MAY 16 JUNE 27

þ.

{.

JULY IO-I1 AUG 8

'è*\

AUG 29

45

Fig. 13. Total soluble carbohydrate content of stems

and leaves (closed circles) and roots (open circle) of

Potamogeton zosteriformis on various sampting dates

during the 1985 growing season. Vertical bars repre-

sent standard error and numbers beside circles indicate

sampling sites. Depth (in meters) for each collection

time is shown on the horizontal axis. A statistically

signif icant relationship betr+een dept,h and total solu-

ble carbohydrate content is shovn for May 16.

SO

LUB

LE C

AR

BO

HY

DR

AT

E u

6 E

eurv

cLl

cos¡

c-l

F-(

H

e F I

ò

3 tt -l z N (¡) -l F: 7 *l 3 (â

t-.H

o

@

Ê

'--# I

|-_{

H,-

€Q

Ë'F

l-û-{ o

&

@l

r-@

JÀ

,À

¡

9þ

47

Table 3. Significant seasonal differences insoluble carbohydrate content of macrophytes in1985. l=Ap 27 Z=YIy 2 3=YIy 16 4=My 30 5=Jn6=Jn 27 7=Jy 10-11 B=Aug B 9=Aug Zg

Ceratophyllum demersumALPHA=O.05 DF=I72 MSE=44.49

DATE

234561

oU

9

N

3036

61BT23327¿4

MEAN

43434642395444/1

^r=

/t 1

7830126449B4I2

GROUPINGSNK

DATE

,7

1

-.7

2-61

a

ALPHA=0.05

^^¿Y39495663772B396

N

Elodea canadensis

GROUPINGTUKEY'S

IJ

B9

MEAN

1

n.s.1

')?q-1

DF=49 MSE=I42.4

3136362B365790')Á

3035733Bo4469726

Myr iophyl l_um exalbescensALPHA=0 . 05 DF= 1 36 MSE= I27 .0

GROUPINGSNK

DÀTE

7B1a7B7B2-6892-7 9'1 I

689

11L

3567B

Y

N

61B1B

3

1B241B')^

GROUPINGTUKEY'S

MEAN

7B7B1a'7p.

Õ

2-5892-7 91R

7363t+

4342573B

4I99901B24100555

GROUPINGSNK

5-7 95-7 95-91-3 B

1-3 B

1-3 B

35-791-3 B

GROUPINGTUKEY'S

67675-93I272

I2

99

3BJö793B

Table 3 (Cont. )

DÀTE

4B

6ö9

N MEAN

35. B035.1643 .22

J33

Potamoget,on foliosusALPHA=O.05 DF=157 l4SE=427 .2

DATE

GROUPINGSNK

N

31B157224245172

1

2{

4567B

996B

MEAN

GROUP]NGTUKEY'S

9664739B936559

996B

1^

46023B1333.2L1B

GROUPINGSNK

Potamogeton qramineusÀLPHA=0.0

23I41ÁAT

23

74T4r-7

DATE

6-B55B6-B6-B55

567B

N

GROUPINGTUKEY'S

6

f

6

MEAN

80.3636.3155.7064.58

23454B232345I413

Potamogeton praelongusALPHA=0.05 DF=19 MSE=208. 3

6-B

6-B6-B

DATE

GROUP]NGSNK

-5

56612

6-B5756

N

B

B

MEAN

92 .8262 .39

GROUPINGTUKEY' S

6-B5756

GROUPINGSNK

B

B

65

GROUPINGTUKEY'S

65

Table

Potamoseton richardsonii

(Cont. )

DATE

AO

67B

N

6q

6

MEAN

93.9383.9986.56

Potamoqeton robbinsii

DATE N

GROUPINGSNK

ll . Þ .

tl . Þ .

367t1

9

MEAN

40.18+1.ro53 .253r.1044.48

6396

GROUPINGTUKEY'S

n.s.n.s.lr . ù .

Potamoqeton zosteriformisALPHA=O.05 DF=86 MSE=2O2 -l

GROUP]NGSNK

DATE

b-Õ378368950tY

7B

¿

3561

B

9

N

1

1

GROUPINGTUKEY'S

L

96056

MEAN

4053ÂotöB45033

6-B378368936797B

3

1

97409111443596

GROUPINGSNK

5-7 92389238923895-7 93 5-B

GROUPINGTUKEY'S

6l¿ó2323

9B9B9

hfl

Table 4. Total soluble carbohydrate contentfor plant organs of 6 macrophyte species duringt,he 1985 season. Means with the same letterwere not significantly different, as determinedin SNK and Tukey's tests at alpha=O.05.

ELODEA CANADENSIS

DATE

May 30

MYRI OPHYLLUM EXALBESCENS

DATE

June 27

August B

August 29

36

TI SSUE

RootsShoot s/leaves

I\T ¡FTqqTlI'll

6 Roots15 Shoots,/leaves6 Roots9 Shoots/leaves3 Roots6 Shoots/leaves


DATE

June 27

MEAN

21 0tr

36.16

POTAMOGETON PRAELONGUS

DATE

June 27

N

6T2

ö¡\

MEAN

69.7545 .22

76.255r .4768.7053.03

POTAMOGETON RICHARDSONI T

T I SSUE

RootsShoot,s/leaves

DATE

July 10-11

1\

B

A.fJ

B

56

POTAMOGETON ZOSTERIFORMIS

TI S SUE

SeedsShoots/leaves

DATE

July 10-11

N T]SSUE

6 Seeds6 Shoots,/leaves

MEAN

47.6252 .26

äA

MEAN

78.191B .02

ÀT ¡FTqqTTtrI!

3 Roots6 Shoots,/leaves

fl

A

MEAN

89 .42f\

n

MEAN

60.2r77.43

¿ì

B

51


and leaves of CeraLophyllum demersum at selected depths

during the 1985 growing season. Sampling dates are

indicated on the horízonLal axis. Vertical bars re-

present standard error.

SO

LUB

LE C

AR

BO

HY

DR

AT

E M

G

68tg

EQ

UIV

GLI

.JC

OS

E G

-¡

Io m Ð I o * F F ff B m I c g

o l) () l,s la $.c

83 6

6@Þ

BåB

rJ| ç.

t re

(¡|

(¡ t\)

53

Fig. 15. Total solubte carbohydrate content in stems

and leaves of Myriophyllum exalbescens at selected

depths during t,he 1985 growing season. Sampling

dates are indicated on the horizontal axis. Vertical

bars represent standard error.

Ltl

,È

= ¡ o ! E c g tfl x Þ @ m I m æ (ø

SO

LUB

LE C

AR

BO

HY

DR

AT

E M

G E

QU

IV C

I,I,C

OS

B G

-I

B B

å å8

@@

@Þ

Þ

å8:g

B!d

6Ðfu

¿r

ot(¡

55

Fiq. 16. Total soluble carbohydrate content, in stems

and leaves of Pot,amogeton foliosus at selected depths

during the 1985 gror,ring season. Sampling dates are in-

dicated on t,he horizontal axis. Vertical bars reÞre-

sent standard error.

(tl

oì

! o { 3 o a m o z 'n o õ Ø c Ø

SoL

UB

LE C

AR

BO

HY

DR

AT

E M

c E

QU

TV

GLU

CO

SE

c-r

EE

sðså

eE(9

>Ë

EE

åop

('' è

o

57


and leaves of Potamogeton zosteriformis at selected

depths during the 1985 g;rowing season. Sampling dates

are indicated on the horizontal axis. Vertical bars

represent standard error.

Gfå

f.3 *gB

s

OE

{sB

8

LO

59

Table 5. Significant inter-site differences in isoluble carbohydrate content of macrophytes (mg g-')during the 1985 season. Means with the same lett'erwere not significant,ly different, as determined inSNK and Tukey's tests at alpha=O.05.

CERATOPHYLLUM DEMERST]I.,ÍDATE DEPTH(M) S]TE N

May2 3 1 6226

May 16 aL

3.5

5

5

6

Jn 13

Jy 10-11

23¿¿

MEAN

423B

43^1-a

TJ

4¿

44

4437

6057

63403635

4737

21

9

¿

9

66

66

33

36

33

6333

4å,2B

5A6A1A2A6A6A

7A7B

Aug B 6.5

MYRIOPHYLLUMDATE DEPTH(M)

I41

¿U1119

5

May 2

May 16

Jn 2'7

Jy 10-11

Aug 29

4A4A:,4BB2B2B

6353

EXALBESCENSSITE N MEAN

22 6 721 6 53

1ABB

2322

¿522

I7

') ')

23

3

6

63

66

3A4B4A2A

2A7BZA2B

OA4B

B17I

504I

51A'NL

44¿J

Table 5. (cont,. )

POTAMOGETON FOLIOSUSDATE DEPTH(M) SITE N

May 2

May 16

OU

Jn 13 5

6

Jn 27

Jy 10-11

.)L

AI

69B

92

B

6

26

66

663

6

36

66

366

6366

MEAN

69 .464.O

80.470.263.9

A]\

)tö

B

frB

A

äB

AA¿\

äABa'

DATE

10360 .210895 .4

7r.455 .2

43 .842 .740.255.051.144.42/1 ll

Jn 27

915

6

10IJ

1116

POTAMOGETONDEPTH (M )

POTAMOGETON R]CHARDSON]IDATE DEPTH(M) SITE N

Jn 27

PRAELONGUSSITE N

POTAMOGETON ZOSTER]FORM]SDATE DEPTH(M) S]TE N MEAN

¿J

22

May 2

Jy 10-1 1

66

MEAN

7B.O46 .8

2322

öB

33

MEAN

94 .693.3

221

I2I

66

66

47 .240 .7orì ?

77 .4

É\

lð

^ö

Table 6. Significant interspecific differences insoluble carbohydrate content of stems and leavesfor each sampting date during t,he 1985 growing sea-son. Significant differences, as determined in SNKand Tukey's tests, are indicated by X's.

61

MÀY 2

.3tot Elõt ät3(rt c.¡l El t¡rl Øl

5l Øl tl --rl Ëlølol ú,lUolol .ol r¡l ol õl:l ãl el üElol xl ol ol rúlt+rl Ol õl Nl Ul

or Ër cjr o.r oir iP. fol iosus

M. exalbescensC. demersum

!. zosteriformisE.canadensis

XXXXXX

64.4663.9943 .4340.9731.30

MAY 16

M. exalbescens

!. fo1 iosus!. zosteriformis

Q, demersum

P. robbinsi iE.canadensis

olÉlolulml0Jl

FllrújXior

i,

ull'Et

tl wlOl 'r'tl ..{

Øt q-¡l El -'{ ol5l .-{l 5l (nl ÉlU)l t{l øl cl Olol ol !l .-'l õl.-rl Ðl ol pl fúl-rl ml El pl dol ol ol ol oltrri N Iti l.rl Ul

Ê.1 ù: ()i o¡ ¡r¡l X

X

x

X

X

X

XXXXXX

74.9073.0253 .4043.7840.1836.35

62

Table 6 (Cont. )

øl'Fl l(rl El al

dl dl dl¿t ¿t Hl(rl ml olol rrl ol.Frl AJI rdl

'rl El clOl ajl rúltl4l õl Ol

p.r .i tf

98.3846. 30

36.73

(nl'ri ¡El Ølrfl r{l cl 0l

ã tDl ol ol -.rlØlbTáqrl Ol El olJl q ol .-rl ol 5l tr1(rl q q !l ol ul ojlol -l '.rl ol .al !l õl',rl al q {rl .{l cj rdl.rl rd rõl Øl rúl Ei Élol r{l t{l ol Xl ol ol'¡¡l Ê4 C$ Nl ojl El Ul

or ^' .-l al jf d uir i

MAY 30

X

Ã

P. foliosusQ. demersum

E.canadensis

93.1392 .82

80. 3'6

69.9150 .72

42.r228.38

JUNE 1 3

XXXXXXXXXX

P. fo1 iosusP. praelongus! . gramineus

P. zosteriformisM. exalbescens

Q. demersum

E.canadensis

tol--rl .-tl..il El ûìlCl trl vl Cl tnlol ol Å .dt ol Øl --rlttl t+{l al d ';l Ul El al ozl Ølõl .-rl al É (/]l Øl al ol Él -.rl!{l t{l (nl d Él Ol al Él Ol -llrõl Ol Ol -{ .'rl ,.Ql t{l .¡l õl ..rl.cl Ðl -.{ 0l .al dl ol Ê fúl xlUl oll -{ rü .Ol rdl El rú cl ol-;l Ol d ¡-d Ol Xl Ol t-d rdl -llr{l Nl "i d ¡{l ol õl E ul

'+{l

^' o.r rJ *, *, if d ÊJ ui' åt X

93

1i33

39

10

24

64

31

o4

BO

63

93

7B

65

62

47

43

39

36

36

35

Table 6 (Cont. ¡

JUNE 27

X

X

X

XXXXXXXXXXXXXxxx

P. richardsoni iP. zosteriformis

P.foliosus!. praelongrus

!. robbinsiiM. exalbescens

Ç. demersum

P. g.ramineus

E.canadensisN. flexilis

í)l.-ll -.{lEl --rl U)lt{l Él nl Ëlol Ol .¡f tnl .Ért olq¡l øl Øt ol ál Ê --rl (Jl.-rl õl 5l Ël ol á al ol!l t{l al Ol Êl tDl Cl Olol øl ol ol -¡l ql --rl .alÐl .Cl .-tl rdl El ol "ql 'rlal Ul -tl Cl rúl El .Al rõlol -¡l ol ol ¡'¡l ol ol Xlsl r{l qrl ul b| !l l.rl ol

ÊJ Orl Ê{l f4l Ê.1 Ol 0{l El X

44

99

2I46

70

49

25

10

84

83

59

57

55

54

53

42

JULY 10-I1

XXXX

! . zoster i formi s

!. richardsoni i! . fol iosus

!.canadensisP. gramineus

Q. demersum

!.robbinsiiM. exalbescens

XXXXXX

øl.F{l .F{l-'{l or El(t)l Cl Cl t{l

-rl Ol Øt ol Ol .F{l6l otl 5l Ul t+.rl Øt El ol --flCl 1'l Ol øl -rl al 4 --tl ullOl ¡{l Él Ol ¡{l ol t¡)l -q Él.õl rõl -dl Ál Ol Ol trl -{ .dl¡!l ,Cl El -tl Ðl ',{l Ol Xl .Qlcl ol fúl rúi Øl -{l El 0¡ .alrúl ..{l !l Xl Ol Ol 0)l -l OlOl þl Ul Ol Nl '+{l 1ãl '+d t{lr"i, o.r Ê, il o, o' ci, ;1 or X

RÂ

90. 97

86. 56

64.5857.0s50. 3s

45.1844 .8435.1631.10

Table 6 (Cont.)

XXxxXXXXxxxxXXXXX XXXXXXXXX

ÀUGUST 8

p. canadensis

!. richardsoni iP. qramineus

M. exalbescens

! . zos ter i formi s

!.foliosuse. demersum

N. flexilisP.robbinsii

Ëtñl rnl

sl ãl

il 6l3l il3l ËlNI UI

orrf X

aê-Hl 0J-.rl El ørl uÚll 5l --rf aÊl úJl .rl o-.rl t{l --rf ,A.ol ol Xl -l.al El ol fúol qjl '-rl x!l õl '1-rl O

^r .ir ått j

44 .4844. 12

43 .22

38.5533.9624 .26

!. robbinsi iÇ. demersum

N. flexilisl"l . exalbescens

P. zosteriformisE.canadensis X X

AUGUST 29

B. Starch

Using selected samples of all species, it !¡as found that

the series of 4 alcohol washes was efficient, in removinq

soluble carbohydrate prior to starch det,ermination. Based on

a total of 5 washes, the cumulative proportion of soluble

carbohydrate removed in the first 4 washes was large, varying

from 99.2 % in P. richardsonii to IO0 % in N. flexilis

(Table 7). Correction factors, subtracted from determined

starch values, had a mean value of 0.33 ng/g for the 10

macrophyte species.

Starch content during the 1985 growing season showed

variation in a1l species (Tab1e B). Mean seasonal values

ranged from 36.6 ng/g for P. qramineus to I44 mg/g for g.

richardsonii. There was no apparent relationship between

vertical distribution and mean starch content.

St,arch content of macrophytes at various depths and

stations during the 1985 season in shown in Figs. 18 to 27.

Linear regression analysis for the sampling dates revealed

the following negative correlations between starch content

and depth: C. demersum on June 13 (R2=0.49, p<O.O2, n=12)

and August 29 1R2=0.83, p<0.001, n=I2), P. foliosus on May 2

t/(R"=0. B1 , p<0.001 , n=12) , May 30 (R'=0.72, p<0.005, n=9 ) ,

June 27 (R"=0.56, p<0.01, n=I2), and July 10-11 (R"=0.28,

65

p(0.005, n=27), and P. zosteriformis on August B

p<0.05, n=9 ) . Negative relationships with depth

suggested for M. exalbescens on May 2 and for B.

mj-s on June 27 and August 29. These relationships were not

(R2=0.48,

\^refe alSO

zoster i for-

signíficant due to insufficient depth representation. Posi-

tive correlations of starch content with depth were observed

for M. exalbescens on August B (Rz=O.79, p<0.005, n=9) andtAugust 29 (R"=0.87, p<0.001 , n=12 ) . Positive relationships

with depth were also suggest,ed for P. zosteriformis on

10-11, M. exalbescens on July 10-11, and P. foliosus on

Àugust B. Again limited depth representation prevented

f rom being signif icant. Vertical dif f erences lrere not

amined in E. canadensis, N. flexilis, !. gramineus, B.

longus, P. richardsonii, and B. robbinsii due to small

size.

66

Mean starch content for each species and sampling date

ïias analyzed for differences in SNK and Tukey's tests (tabte

9). Only shoots and leaves Ì¡ere available for analysis. The

starch content of C. demersum tended to decrease seasonally.

Levels on May 2 and May 16 h¡ere significantfy higher than

June, July, and August B values. There lrere few significant

seasonal differences in mean starch levels for U. exalbescens

in 1985, wj-th the mean on June 27 significantly exceeding the

June 13 level. P. foliosus showed a tendency to accumul-ate

starch after a seasonal minimum in mid-May. The mean starch

July

content for June 27, July 10-11, and August B was signifi-

cantly higher than the May 16 level. An overall seasonal

increase in starch content .t,Ias observed in P. zosterif ormis.

The mean value f or August 29 \"/as signif icantty higher than in

June and July. The August B leve1 was significantly higher

than in June.

these

ex-

prae-

sample

Q/

The small number. of sampling dat,es made it difficult to

fully examine seasonal- trends in the remaining species,

although some significant differences \{ere observed. The

starch content of N. flexilis rras significantly higher on

August B than on June 27 . In P. sramineus the mean starch

level f or June 13 and July 10-11 'h¡as signif icantly greater

than on August 8. The starch content of P. praelongus was

significantly higher on June 13 than on June 27. Levels in

P. richardsonii on June 27 significantly exceeded the mean

for the July sampling dat,e.

Starch content in q. demersum, M. exalbescens, E. folio-

sus, and P. zosteriformis was examined at selected depths

(fiqs. 28 to 31). Starch levels in e. demersum tended to

decline sharply from early t,o mid-season at 2, 3.5, and 5 m.

Samples from 2 m showed a steady accumulation from June 13

to the end of August. Starch content at 3.5 m also in-

creased, from August B to August 29. Starch in M. exal-

bescens showed inconsistent seasonal patterns over a dept,h

range of 1 to 3.5 m, and levels tended to increase with

depth. fn P. foliosus, starch showed an overall seasonal

increase at 4 and 6 m, and a similar accumulation with time

was suggested in P. zosteriformis at depths of 2 and 3.5 m.

Variation in starch content was observed for macro-

phytes growing at the same depth in different locations dur-

ing the 1985 growing season (Table 10). There was a greater

number of significant differences in starch than in soluble

carbohydrate, although the sample number for starch analysis

r{as smal ler . Starch content

cantly greater at station 22

June 27, and August 29. fn C. demersum, the starch tevel

was significant,Iy higher at site 23 than at sit,e 22 on May

16. Plants at station 9 contained significant,ly more starch

than at station 2 for e. demersum and !. foliosus on June 13.

Starch content in P. foliosus h¡as significantly higher at,

site B than at site 6 on May 16, while the reverse signifi-

cant relationship occurred for this species on June 13.

Interspecific differences in mean starch content h¡ere

observed for some of the sampling dates during 1985 (tabte

11). Comparisons were made using SNK and Tukey's tests

(Appendix ). No significant differences were found for the

4 species represented on May 2 and the 5 species represented

on May 16. The starch content of B. praelonsus was signifi-

cantly greater than all other species in June 13. P. rob-

binsii and E. richardsoniÍ showed the greatest number of

sÍgnificant differences with_ other species on June 27, with

the lowest and highest starch content, respectively. Rela-

tively hiqh starch content was observed in P. foliosus and

relatively low tevels in C. demersum on July 10-11, and these

^*^^.i ^^ l, -,1 +1Þ¡,sLrçù ¡rqu urìê gfêâtest number of significant differences on

this date. On August B, !. foliosus and !. zosteriformis

contained more starch than all other species, t¡ith some slg-

nificant comparisons. P. zosteriformis also contained sig-

nificantly more starch than other species on AugusL 29.

P. sramineus had lower levels of starch than all other species

6B

in M.. exalbescens was signifi-

than at station 23 on May 16,

on June 13, July 10-11, and

cant comparisons with other

69

August B and gave

cno¡ ì oc

some slqnr"t].-

Table 7. Proportion of soluble4 of a total of 5 alcohol washesfactors for starch content.

Spec i es

Na i as flexilis

Potamoqeton zosteriformis

E]odea canadensis

Potamogeton foliosus

P. praelongus


Mvriophyllum exalbescens

Potamogeton g_ramj nCl¡;

P . robbi ns j. i

P. richardsoni i

carbohydrate removed afterand correspondinq correction

NPercent CorrectionSoluble Factor

Carbohydrate (mg/g)

6

9

9

9

6

9

9

9

9

6

100

99. 9

99.6

99.6

99 .6

99.5

99.5

99.5

99 .3

99 .2

0. 00

0.07

o .20

o .23

0.40

o .23

o .23

0. 30

1 .00

0.60

\ì

ô'r'aD-Le Õ

season.Overall seasonal starch

N represents the number of

Spec i es

Ç_ef a-!_=o_plr: 1 I um d eme r s um

Elodea canadensis

My ri.qphy I .L¡¿m eÄê l_þc E sen €

Na 'i as f lexi 1i s

lotamogeton foliosus

P. gramineus

P. prael!¡çLu-s

P. richardsonii

content (*S g-1) of macrophytes during t,he 1985samples studied.

StarchRange

P. fgbb_]lqErj

P . Zo_s.lçÃiferrnr €

16 .4

37 .8

2r.o

94.5

36.7

30.9

90. 1

101

25 .3

23 .9

165

170

194

r26

228

40 .3

147

1BB

r32

774

Mean

56.3

104

92.8

109

118

36.6

118

144

82 .2

110

NDept,h

Range (m)

31

9

2T

2

30

J

aL

2

6

I2

I

I

1

1

2

^q

13

13

1.5

6.5

3

MeanDepth (m)

4.O

3.1

2.7

7.2

5.0

2.7

2.O

1R

2.6

A1

t\

,l

L

-2q

1A- It

{

72

Fiq. 18. Starch content in stems and leaves of

CEratophvllum demersum on various sampling dat,es

during the 1985 growing season. Vertical bars re-

present standard error and numbers beside circles

indicate sampling sites. Depth (in met,ers) for each


Statistically significant relationships between depth

and starch content are shown for June 13 and Auqust

29.

CERATOPHYLLUM DEMERSUM

T0I(,lrt-U'('=

o23o23

e23

o2p<.005

125JN13

tuee.

8i cl'

a

{"

23¿f5fð.tA8

\ì(,

p<. 00 1

234567429

74

Fig. 19. Starch content in stems and leaves of

Elodea canadensis on various sampling daLes during

the 1985 growing season. Numbers besid,e circles in-

dicate sampling sites. Depth (in meters) for each

collection time is shown on the horizonLal axis.

ELODEA CANADËNSIS

r(,:E()cc

FØ(,

=

120

100

15

M2

13

M16

1

M30

1

JN13

1

JN 27

12 34JY 10-11

3.s

A8

{L¡

1.75

A29

76


Myriophyllum exalbescens on various sampling dates


present standard error and numbers beside circles in-

dicat,e sampling siLes. Depth (in meters) for each col-

lection time is shown on the horizontal axis. Statis-

ticalty significant, relationships between depth and

starch content are shor.sn f or August B and August 29.

MYRIOPHYLLUM EXALBESCENS

180

160

140

1n

100

80

60

¿to

T(,

()CE

t-v,o= ttt *., €)z

I

A27

91

!Ðzg

Jt{ t3 .,n{27

83

lðtæ,

,JY m-ll

p<.005

1þs

{{

gzsp<.001

7B

Fig. 27 . St,arch

Na 'i as f lexi 1i s at

growing season.

dates is shown on

content in st,ems and leaves

sampling site 3 during the

Depth ( in met,ers ) f or the 2

the horizontal axis.

of

1985

co1 lect i on

NAJAS FLEXILIS

To

ð tooæ

È<Øs80=

1.5

A81

JN 27

BO

Fig. 22. St.arch content in stems and leaves of

Potamogeton foliosus on various sampling dates during

t,he 1985 growing season. Vertical bars represent

sùandard error and numbers beside circles indicate

sampling sites. Dept,h (in meters) for each col1ec-

tion time is shor+n on the horizonLaL axis. Statis-

tically significant relationships between dept,h and

starch content are shor.¡n f or May 2 , May 30, June 27 'and Julv 10-11.

220

200


Õt

ËtooIo(rÉ 12ov,oEroo

e2

Or

o25

e1

p<. 00 1

o@o

3rs

456M2

Þ*ao86Os

@1

o

p<.005

5

M16

82

p<.05 p<. 005

óz

Fiq. 23. Starch content in stems and

Potamogeton gramineus at sampling site

dates during the 1985 growing season.

for each collection time is indicated

axis.

leaves

22 on

Depth

on the

of

various

lin mo{-orqì\¡¡¡ ¡r.vvv!v/

hori zonLaL

B3

POTAMOGETON GRAMINEUS

TCIgo

(J

t- 20Ø(5

=

32JN 13 JY 10-11

3

AB

B4

Fiq. 24. Starch content in stems and leaves of

Potamogeton praelonqus at sampling site 23 during June

of the 1985 growing season. Sampling depth (in meters)

is indicated on the horizonLal axis.

B5

POTAM OGETON PRAELONGUS

160

140

To120

()É,

t-¿n 1OO

(5

=80

2

JN 13

2

JN 27

B6


Potamoqeton richardsonii at sampling sites 22 and 3

during the 1985 growing season. Collection dept,h (in

meters ) i s indicat,ed on the hori zonLaL axi s .

a'-l

POTAMOGETONRICHARDSON II

lia,LOÉ,

F.Ø(,E

2 1.5JN 27 JY 10-11

BB

Fig. 26. Starch content

Potamogeton robbinsii at

various dates during the

lection depth (in meters)

ta1 axis.

of stems and leaves of

sampling sites 3 and 9 on

1985 growing season. Col-

is indicated on the horizon-

B9

POTAMOGETON ROBBINSII

Yio

80.rC)cc

t-'Ø 60o=

5

M16

1

JN 27

Ðg

1.5 5

JY 10-11 AB

1.5

429

1.75

90

Fig. 27 . Starch content in stems and leaves ofPotamogeton zosteriformis on various sampling dates dur-ing the 1985 growing season. Vertical bar represents

standard error and numbers beside circles indicatesampling sites. Depth (in met,ers) for each coltectiontime is shown on the horizontal axis. statist,icallysignificant relationships between depth and starchcontent are shown for July i0-11 and August, B.

91


812

01

180

60

1¿lo

r20

100

80

60

¿lo

æ

o

a:E(JE

u,

oE

o..ot

92


Ceratophyllum demersum at selected dept,hs during t'he

i9B5 growing season. Sampling dates are indicated on

t,he horizontal axis. Vertical bars represent stan-

dard error.

93

CERATOPI{YLLTH Ð€$¡Effi UM

120

o

ðt*G

u,

o8o=

@Aæ 2o o(þo o 3.5@6M5

94

Fiq. 29. Starch content

Mvriophvtlum exalbescens

the 1985 grolring season.

on the horizontal axis.

dard error.

in stems and leaves of

at selected dept,hs during

Sampling dat,es are indicated

Vertical bars represent stan-

95

IÁYRIOPHYLLUH EXALBESCE!{S

Õù-oo

oto oooo

"nTqI

II

æa@ IooGoc2@3* 3æ!æ $.9

oOaoo

\c

A I M | ¡ l^ J I A I

To-()Et-ø(,=

vo


Potamogeton foliosus at selected depths during the

1985 growing season. Sampling dates are indicated on

the horizontal axis. vertical bars represent stan-

dard error.

YI


*¡ø4w@æg

I

(J*fØ

E

Af !U t

9B

Fiq. 31. Starch content in stems and

Potamogeton zosteriformis at selected

1985 growing season. Sampling dates


leaves of

depths during t,he

are indicated on

(o (o

E G I t! I N I m 3 ? I a &

MG

ST

AR

CH

G-I

100

Table 9. " Significant seasonalstarch content of macrophytesl=Ap 27 . 2=Nly 2 3=Nty 16 =Itty6=Jn,27 7=Jy 10-11 B=Auçt B


DATE

¿a

57B

9

N

12 105. 141B 73.2512 42.0224 38. B015 38.7712 52.89

MEAN

differencesin 1985.30 5=Jn 1 3

9=Auçt 29

GROUPINGSNK

DATE

ALPHA=0.05

3525¿52323¿3

234567B

9

N

IN

Elodea canadensis

7-97-9

GROUPINGTUKEY'S

5?

3363J

MEAN

DF=19 MSE=35.65

14877

i1B1a

169126

3B57

35252323232

34B9B96027BO

49T7

Myr r ophyllum exalbescens

GROUPINGSNK

3-9246-923568

7-9tó

DATE

1326312536979B9912

246-92-4 7-923562-7 92-B

GROUPINGTUKEY's

3-9246-8

9 2 35689

N MEAN

246-92-4 1-9

B9 23 56892-7 92 4-B

95r22

A/l--I2B

B2r02

B4

B465239B76B99571

GROUPINGSNK

n.s.

n.s.26

lr . Þ .

1r . ù .

GROUPINGTUKEY' S

n.n.66J

nn

S.S.

S.

Table 9 (Cont. )

Najas flexilis

DATE

101

6R

N MEAN

96.55I20.93

Potamoseton foliosusALPHA=O.05 DF=83 MSE=IB2B

5J

DATE

GROUPINGSNK

21239495 15672727B6

N MEAN

113.9551.3379.95

100. 11I45 .13r47.23r42.24

B

6

GROUPINGTUKEY' S

GROUPINGSNK

Potamogeton gramineus

ö6

DATE

6-BÂ_R

2 ,/1JTa^JT1/1

5

B

N

GROUPINGTUKEY'S

333

MEAN

39. B637.2032. B0

Potamogeton praelongusÀLPHA=0.05 DF=4 MSE=10.35

3¿6

333

6-B-

DATE

4

GROUPINGSNK

N

'785B57

MEAN

r44.2991.133

GROUPINGTUKEY'S

GROUPINGSNK

B

I57

65

GROUP]NGTUKEY'S

65

Table 9 (Cont. )

Potamogeton richardsoni i

DATE

702

MEAN

184.01104 . 81

DÀTE

GROUPINGq t\T1¿

367R

9

MEAN

100 . 3158.6877.9595 .4I82.75

6

336

{

Potamogeton zosteriformis

GROUPINGTUKEY'S

DATE

GROUPINGE ÀIT¿

n. s.ne

n.s.n.s.

MSE= I262

1

6

5

7B

9

MEAN

70.2877.17

104 . 81I27.3616r .44

66996

GROUPINGTUKEY'S

n.s.n.s.rt. ò..n.s.n.s.

GROUPINGSNK

B9B995695-B

GROUP]NGTUKEY'S

B9öv956

103

Table 10. Significant inter-site differencesin starch content of macrophytes (mg/g)during the 1985 season. Means with t,hesame letter were not significantly different,as determined in SNK and Tukey's tests atalpha=0.05.

DATE

May 16

CERATOPHYLLUMDEPTH ( M )

Jn 13

Jy 10-11

2

5

4

6

DEMERSUMSITE N

2332231323

9323

14313

20311 319 3

Aug B 6.5

MEAN

MYRIOPHYLLUMDATE DEPTH(M)

95. s51.676443 .6

May 16 2

Jn27 2

öB

nB

1\

B4320

33?n

59332I

51t7

06

59

99B

¿

z

Jy 10-1 1

Aug 29

65

EXALBESCENSSITE N MEAN

fì

õ

¿\

BC

¿l

B33

22 3 72.823 3 72.7

PATE

l'{ay 2

May 16

¿¿ J233

POTAMOGETON FOLIOSUSDEPTH(M) SITE

r'723

22z5

r7694 .5

7\d

b

.¿\

B

öB

^B

3J

3

67.O^È.

A

85.511 /1

23ÏJ

93B363

MEAN

11/1IL-

48 .7d

60.154 .438. B

ABC

Tabte 10 (cont. )

POTAMOGETON FOLIOSUSDATE DEPTH(M) SITE N

Jn 13

104

Jn 27

Jy 10-1 1

93236383

6323

15 36393

10 311 316 3

POTÀMOGETON ZOSTERIFORMISDATE DEPTH(M) SITE N MEAN

MEAN

Jy 10-11

L2T57 .2726104

r5297.O

199162155

t45r2460.7

ÀB

ÀB

AB

fl

BB

ABc

4r2313

r32106

AB

105

Table 11. Significant interspecific differences instarch content of stems and leaves for each samplingdate during the 1985 growing season. Significant dif-ferences, as determined in SNK and Tukey's tests, areindicated by X's.

JUNE 13

Ol.F{l

Él alv\ col r1l cl.{ .Jl ^¡

¡rl Alüu\ol ùl ül Et tlÉ 5l Él --rl orl 5l olqr/)lolÞlolølcl-l ol õl ol ,ol kl .-tlq¡ -4 øl Ðl ol ol Elrdl -rl Él ol -rl El ol¡¡l O ol ol Xl ol r¡lO¡ t+{l Ol Nl ojl 1'l tlo, of r,ir o, jf c,r ,, X

l. praelongus

!.foliosus!.canadensis

!. zosteri formi s

M. exalbescens

Q. demersum

!. qramineus

X

X

X

XXXXXX

,]UNE 27

744 .3100. 1

77.6070 .2844.9842.0239.86

ûl.r{l .r{l.-rl 0)t ElÉl tr)l Él vÄ !lol .-{l ol J ol .-rløl al Øt ul (/)t Þ| +¡l -¡lõl Él al Øl --rl É --l Øl¡{l Ol al Ol -|l q l.ti Élrdl õl Ol .Al .-tl -{ OJl .-ri.Cl rúl --rl -rl Xl 0l Ðl ,OrUf Él -{l rõl Oi rd Øl Al-xl rúl ol Xl -rl t{ ol oìl{l Ul r+{l Ol '+rl O¡ Nl !r0{l Éll O{¡ tl Zl O¡ O.l 0{l

P. richardsonii!. canadens i s

P.foliosusM. exa lbescens

N. flexi I is!. praelongus

p. zosteriformis!.robbinsii

X

X

J(

XXXXXXX

184.0169.3745.7728 .896.5591.1377.t758.68

Table 11 (Cont.)

106

JULY 10-1 1

(nl...{t .-ll..rl El olt/ll Êl ¡{l Él.F{l ol ol ol .F{t (rl

Ulr Øl al '+{l Ul .-rl El alJl Él ol .il ol Øl 5l olal ol r.{l ltl ol Él ol ÉlOf ol rúl OI .al ..rl t{l ..{l.'-{l rdl .Cl Ðl -rl .ol ol Él-il Él Ul (nl rúl .al El 16lOl rõl .-tl Ol Xl Ol q¡l trl'{"11 Ul ¡rl Nl Ol t{l õl En

0., oil or 0., Ëf o.r ,jr or

! . fo1 iosusE_. canadens i s

P.richardsoniiP. zosteriformis

M. exalbescensP.robbinsii

Q. demersum

!. gramineus

X

X

XXXXXX X

AUGUST 8

r47.2126. B

104.8104.882 .8977.9538.8037.20

(t) |

'Ft lEl alþl Él uìlO¡ Ol -dr .;l Ølull t+{l (l)l Ul .-tl El ol Jl5l .-rl --rl ml Øl 5l sl olol t{l r-rl AJI Él rnl Ol Élol ol -dl .al ..rl ql El .;l.Frl Ðl Xl .rl "al ol ol El-rl rrl aJl rõl .al El Él olol ol .{l Xl ol ol ol rrl',ll Nl q{l ojl ¡{l gi Ul Ct

o' o, åt jr o, ..i, r'ir o.r i

P.Lori-as-u€!. zosteriformis

N. flexilisM . exa lbescens

l.robbinsiiQ. demersum

l. canadens i s

P . qramineus

X

X

X

Ã

Ã

X

I42.2727.4r20.9103.095 .41

38.49?) An

Taþ1e 11 (Cont.)

rol

ÀUGUST 29

ol'F{ |El at{l Éol GJq-.rl O.F{l Atrl 0Jol .aÐl -rol rõol xNt o

*r t

!'.zosteriformisM. exalbescens

P.roþÞ1nsr1

8..-".*""t"C. demersum

a

'F{

t{

Øl'Fllml ElÉl 5lol ttlgl t{lol olél Élrdl Olut .õl

oir .ilI o.l

X

X

X

X

161.484.7I82.7557.1752.89

C- Total nonstructural carbohydrate

The starch:soluble carbohydrate ratio showed differ-

ences among t,he 10 macrophytes during the course of the

growing season (Table 12), with mean values ranging f.rom

0.67 in P. sramineus to 2.69 in N. flexi1is. Only P. qrami-

neus had a ratio of less than I, while 6 species had rat,ios

approaching or exceeding 2.

Variation in the composition of total nonstructural

carbohydrates r4¡as observed during the season (Figs. 32 to

4I). Seven of the species examined gave no significant com-

parisons in SNK and Tukey's tests (tante 13). The small

number of samples rrras sometimes responsible for the lack of

significance and in some cases only 2 or 3 sampling dates

'were represented. The proportion of carbohydrate in the

form of starch had an overall range of 30 to 85 %, with

Ievels generally exceeding 40 %.

The proportion of starch in C. demersum was significant-

ly higher on May 2 (7O %) than on July 10-11 and August B.

There was a tendency for the proportion of starch in P.

foliosus to increase as the season progressed. Levels on

June 27, July 10-i1, and August B were significantly higher

than t,he level on May 16. This seasonal trend was also

observed in P. zosteriformis, lqhere the proportion of starch

increased consistently between June 27 and August 29.

Levels in late AugusL (83 %) \{ere significantly higher than

on June 27 and July 10-11. The proportion of starch l¡as

also significantly greater on August B than on June 27.

108

109

Starch in E. canadensis remained relatively abundant ( 66 %)

throughout the season, with the exception of t,he August B

sampling date. The proportion of starch gave a seasonal

minimum j-n M. exalbescens and p. robbinsii, orr May 16

June 13 and JuIy 10-11, respecüive1y.

Few significant, interspecific differences in starch:

soluble carbohydrate ratios r^rere observed during the 1gB5

season (tabte 14). This was at least in some cases related

to the sma1l number of samples in which starch could be

analyzed. On May 2, S:C ratios for E. canadensis signifi-

cantly exceeded ratios for q. demersum, M. exalbescens, and

P. f oliosus; and on May 30 ratios r,irere signif icant,ly larger

than in P. foliosus. E. Sanê_dCnElS also had a larg:er S:C

ratio than all other species represented on June 13 and June

27, although comparisons were not consistently significant

in SNK and Tukey's tests.

Table 12. Overall seasonal starch:solubleratios (mg mg-1 ) for macrophytes during the

Species


Elodea canadensis

lry_rj_Sphyf_1gm exa 1 be s cen s

Naj as f l-exilis

Potamogeton foliosus

P. gramineus

P. praelongus

P. richardsonii

P. robbinsi i

P. zosteriformig

Starch: Carbo .

Kat10

carbohydrate1985 season.

o .42

o .42

0 .82

3. 89

5 .49

Mean

o .46

0 .49

1 1-

0.48

o .52

1.31

2 .6r

1 .96

2 .69

2 .05

o .67

1 ?Â

1.58

I.82

2 .19

N

4. B5

7.02

r .97

3 .06

30

10

20

1

29

J

2

z

5

T2

H

111

Table 13. Significant seasonal dlfferences inproportion of starch in carbohydrate contentof macrophytes during the 1985 season. 1=Apr 272=l4ay 2 3=lulay 16 4=May 30 5=Jn 13 6=Jn 277=Jy 10-11 B=Àug B g=Auq 29 Alpha=O.05

DATE

¿

357a

9

464B

54

ç_ÐBÀTAIHYLLUL4 pEME R s uM

MEAN GROUPING GROUP]NGSNK TUKEY'S

.7001

.5BOB

.4879

.4069

.437 B

.5T2I

DATE

aL

3,/l-561

R

Y

5'789n.s.¿

¿.)

¿

ELODEA CANADENSIS

1

1

1

1

1

¿

1

1

MEAN GROUPINGSNK

846467947 6407 24682456628297 37 02r

7Bn. s.n.s.¿

2n.s.

DÀTE

nnnnnnnn

I¿

356

B

9

ùÞ

Þ

S

Ð

ùÞ

ò

MYR] OPHYLLUM EXALBESCENS

GROUPINGTUKEY' S

1

2I1

3334

MEAN GROUPING GROUPINGSNK TUKEY I S

nnnnnnnn

566 36385487 B

47 307 r296297603 1

603 1

òb

S

S

Þ

S

5

nnnnnnnn

S

òòòÞ

Ð

Ð

ù

nn

nnnnnn

Þ

ò

S

S

5

Table t: (Cont. )

DATE

712

MEAN

.7295

.7748

NAJAS FLEXILIS

DATE

234561

B

GROUPINGSNK

n. s.n.s.


4335492

MEAN GROUPINGSNK

.6033

.4165

.439r

.5079

.687 6

.7 764

.6994

GROUPINGTUKEY'S

n.s.n.s.

DATE

n. s.678678It.ò.aÂ3434

56B

POTAMOGETON GRAMINEUS

1

1

1

GROUPINGTUKEY ' S

MEAN GROUPINGSNK

DATE

.3315

.5061

.3368

n.s,67671

5+1AJT

3


MEAN GROUPINGSNK

.6085 n. s.

.5380 n. s.

lr . Þ .

n.s.lr . ò .

DATE

GROUPTNGTUKEY'S

n.s.n.s.n.s.

POTAMOGETON

MEAN

.6636

RICHARDSONI I

GROUPINGTUKEY'S

n.s.n.s.

GROUPINGq ÀTI¿

lt . ù .

GROUPINGTUKEY'S

n.s.

Table t3 (Cont. )

DATE

36

B

i13

POTAMOGETON ROBB]NS]I

1

1

Ii

MEAN GROUPING GROUP]NGSNK TUKEY I S

.7 r40

.5547

.327 L

.7542

.6504

DATE

67o

9


n.s.n.s.n.s.na

n.s.

223?

2

MEAN

.5562

.4470

. s502

.t5rl

. B2B5

GROUPING GROUPINGSNK TUKEY'S

n.s.n.s.n.s.n.s.n.s.

9B996567

n.s.B99667

1.T¿.

Table 14. Significant interspecific differencesin starch:so1ub1e carbohydrate ratios of macro-phytes during the 1985 season. 1=Q.demersum2=8. canadensis 3=I[. exalbescens 4=N. {]ex:liS5=-P. foliosus 6=P.gramineus 7=P.praelongusB=! . r i chardsoni i 9=Probb.!_n_gjj 10=P . zoster i f ormi s

SPEC I ES

MAY 2

ALPHA=O.05 DF=7 MSE=O.453

¿

1

J5

1

424

MEAN

5 .492.40T.7Br.74

SPEC I ES

GROUPINGSNK

MAY 16ALPHA=O.05 DF=10 MSE=O.670

921

J5

135z

az

1

1

43

MEAN

2 .462.tr1 .900 .97

GROUPINGTUKEY'S

135?

22

SPEC I ES

GROUPINGSNK

MAY 30ALPHA=0.05 DF=2 MSE=0. 1 1 1

n.sn.sn.sll . Ð

n.s

GROUPINGTUKEY' S

ll . ù .

ll . Þ .

tr . Þ .n.s.

MEAN

3.28ñ a?

GROUPINGSNK

5a

GROUPINGTUKEY' S

5L

Table 14 (Cont. )

SPECIES

JUNE 13ALPHA=O.05 DF=B MSE=O .I16

115

2

101

536

1

Iz45I

1

MEAN

2 .62

r .261 .061.050.90o .49

GROUPINGSNK

6n.s.n.s.n.s.n.s.n.s.z

SPEC I ES

JUNE 27ALPHA=0.05 DF=6 MSE=1 . 21

2345ö91

610

GROUPINGTUKEY'S

n.s.n.s.n.s.n. s.rl .b.

n.s.n.s.

1

31

41

1

I1

2

MEAN

4

aL

2

1

1

1

I0

6BB169399724I702BB

GROUP]NGSNK

SPEC ] ES

n.sn.sn.sn.sn.sll . Ð

n.sn.snq

JULY 1O_1 1

ALPHA=0.05 DF=21 MSE=0 .879

532

10B

1

9

GROUPINGTUKEY' S

I3331

81

l'ì

nnnntt

nnn

MEAN

? 1n

T.7T

1.180.700.48

Ð

Þ

Þ

ùS

Ð

S

ò

GROUPINGSNK

n.s.n.s.

n.s.rl . ù .

nq

n.s.

GROUPINGTUKEY'S

1

n. s.n. s.n.s.n. s.5n.s.

Table 14 (Cont. )

SPEC IES

AUGUST B

ALPHA=0.05 DF=9 MSE=1 .00

495

103a

6z

116

i1a

J3

11

MEAN

3JJ21

000

250605'78

87B65142

GROUPINGSNK

SPECIES

n.sn.slt. ò

lI . ò

tt . ò

tr.5

lI . ùnq

AUGUST 29ALPHA=O.05 DF=7 MSE=2.61

102J91

GROUPINGTUKEY'S

1-L

4i4

tl

nnnnnnn

MEAN

4.982 .352 .32

1 1A

ù

5

òÞ

S

Þ

GROUPINGSNK

n.s.lI . ù .

n. s.II . ò .

GROUP]NGTUKEY'S

n.s.n.s.n.s.n. s.n.s.

IT7

Fig. 32. Proportion of starch (upper) and sotubte car-

bohydrate (lor.¡er) in stems and leaves of Ceratophyllum

demersum on various sampling dates during the 1985

grolring season. Depth (in meters) for each collection

time is indicat,ed on the horizontal axis.


80

F.

É, zo

=ts60

U50

JFoF ¡lo

Fz(¡.¡

Hsof¡¡

12 34 5

M2

23456M16

2 3 4 5 6 7

A8

234567

429

119

Fig. 33. Proportion of starch (upper) and soluble car-

bohydrate ( tower ) in stems and leaves of Elodea cana-

densis on various sampling dates during t,he 1985 growing

season. Depth (in meters) for each collection t,ime Ís

indicated on the horizontal axis.

3¡ ^)(,

t

3- õï s

)

3 c- zr (t

PE

RC

EN

T T

OT

AL

lå8

(- Z¿

À)

CA

R B

OH

YD

RA

TE

tði

oi¡r

m r- o m Þ o Þ z Þ o m z o Ø

Þ* 8d

0zt

T2I


bohydrate (1or+er) in stems and leaves of Myriophyllum

exalbescens on various sampling dates during the 1985

growing season. Depth (in meters) for each collection

time is indicated on the horizontal axis.


Fzo

r60

asoJIl-P¿o

Fz!{ 30

20

1

AP2723M2

2 3413M16

1

JN1312JN 27

23JY 10-11 A8

N)tJ

1.5 2A29

t23


bohydrate (1ower) in stems and leaves of Naias ftexilis

on 2 sampling dat,es during t.he 1985 growing season.

Depth (in meters) for each collection time is indicated

on the horizonLal axis.

C. zr t\) Þi

@('|

PE

RC

EN

T T

OT

AL

CA

RB

OH

YD

RA

TE

t88d

8z Þ C

- Þ v, .tl m x ø

H t\) ,b

725

Fig. 36. Proportion of starch (upper) and solubte car-

bohydrate ( lower ) in stems and leaves of Potamogeton

foliosus on various sampling dates during the 1985

growing season. Dept,h ( in meters ) f or each collect,ion

time is indicated on the horizontal axis.

5, o)

PE

RC

EN

T T

OT

AL

8È8

à3 cè O

çt

t o

CA

RB

OH

YD

RA

TE

8ð8

ù

(- zoì

(¡)

(D 6t a¡

c-¡

z N

(,|

E o { Þ o fñ -{ o z Tl o f- õ U)

f.' (' ¡

9ZI

t27

Fig. 37. Proport,ions of starch (upper) and soluble car-

bohydrate (lower) in stems and leaves of Potamogeton

qramineus on various sampling dates during the 1985

girowing season. Depth (in met,ers ) f or each collection

time is indicat.ed on the horizontal axis.

<- z Jq)

(¡)

c- 3'.)

\¡

PE

RC

EN

T T

OT

AL

CA

RB

OH

YD

RA

TE

EÈ

88d

B É

')

! o ; 3 o o m o z G'

Ð Þ Ë z m c Ø

tJ

t29

Fiq. 38. Proportion of starch (upper) and soluble car-

bohydrate ( lower ) in stems and leaves of Potamogeton

praelonsus during June of the 1985 growing season.

Depth (in meters) is indicated on the horizontal axis.

C- =rs

€.)

C. ZN

19

PE

RC

I|NT

TO

TA

L C

AR

BO

HY

DR

AT

E

8888

ð! o il = o o m o z ! v Þ m o z o c Ø

H LÀJ

131

Fiq. 39. Proportion of starch (upper) and soluble car-

bohydrate (lower) in stems and leaves of Potamogeton

richardsonii on 2 sampling dates during the 1985 grow-

ing season. Depth (in meters) is indicated on the

horizont,al axis.

<- zlu

N) ! C o('|

I

PIÌR

CIIN

T T

OT

AL

CA

RB

OIIY

DR

AT

E

8È88

d! o .-l o o m { o z Ð õ Þ ¡ o U) o z

Fr

(¡J l\)

i33

Fig. 40. Proport,ion of starch (upper) and soluble car-

bohydrat,e in stems and leaves of Potamogeton robbinsii

on various sampling dat,es during the 1985 growing

season. Depth (in meters) for each collection time is

indicated on the horizontal axis.

=J (t

lo) C

. N \.¡ c- ötrr

I

PIÌR

CIIN

T T

OT

AL

CA

RB

OH

YD

IIAT

Ii(,

)S(¡

o){

oooo

o

Þ:¡

co (r

l

Þ+

tsd'

! o ; = o o m { o z 1 o q, q, z IU

J,N

13s

Fig. 4I. Proportion of starch (upper) and soluble car-

bohdyrate ( lower ) in stems and leaves of Potamogeton

zosteriformis on various sampling dates during the 1985

growing season. Depth (in meters) for each collection

time is indicat,ed on the horizontal axis.

! o { Þ = o o m { o z N o U' { m 2 .1

1 o u 5 Ø

CA

RB

OH

YD

RA

TE

8d8

PE

RC

EN

T T

OT

AL

OJè

C'l

ooo

t9

fior ¡

,tì'

öst

t i¡

o,

Þå

@ .(D o

9t T

lÛ

Þ ¡¡r

0l(o

å

737

D. Individuat soluble sugars

The recovery efficiency of the ion-exchange and paper

chromatography isolation procedure varied for the 6 refer-

ence sugars (Tab1e 15). The proportions recovered ¡¿¡r-rarì

from 67.8 to 85.6 % for raffinose and stachyose, respec-

t,ively. Recovery of total soluble sugars in the chromato-

graphic isolatÍon procedure \,üas compared to the amount

quantified in the crude extract (fante 16). The efficiency

of the ion-exchanqe and paper chromatography ranqed from

32.6 % of total soluble carbohydrate in U. exalbescens to

BI .4 % in P. praelongus, rr'ith a mean for all species of

56 .t %.

Chromatographic dat,a for reference compounds and crude

sample extracts are summarized in Table 77. Good separation

of individual sugars was achieved in the 10 species of mac-

rophytes, êod all were found to contain fructose, glucose,

and sucrose (Fiq. 42). The color reactions for sug,ars in

crude sample extracts compared well wit,h those of standards,

with f ructose being orange-brolrn, gilucose blue-grey, and

sucrose brown. Sugars from crude sample extracts tended to

have slightly lower Rf, rulues than the standards.

The 4 additional sugars isolated from C. demersum (Fig.

43) Ìrere not positively identified by paper chromatography.

The first (A) and third (C) spots from the origin resembled

stachyose and raffinose, respectively, in terms of color

reaction. The fourth spot from the origin (D) gave a blue

reaction similar to that of melibiose and lactose. The 3

138

Table 1 5. Recovery efficiency ofreference sugars in chromatographicisolation procedure.

Sugar

Stachyose

Melibiose

Sucrose

Fructose

Glucose

Raf f i nose

Percent I +\H l

Hecovery

Bs.6 (3.2)'7e.o(4.6)

77.8(3.5)

75.6(¡.2)

7O.6(3.0)

67 .B(2.8)

139

Tabte16. Recovery efficiency of solublecarbohydrate in chromatographic isolation method.

Spec i es

praelonguszos ter i formi srichardsoniicrramineuscanadens i srobbinsi_ifol iosusflexi 1 i s

demersum

*".r"

B

3

3

11

5

32

3

B1

69

65

64

63

60

56

39

33

32

4

5

9

4

4

R

n

6

6

6

(o(o(3

7)

B)

6)

6)1lr)

4\tl

2)

0)

2)

2T

25

B

AI

5

3

6

3

2

Table 17. R vaco]or reactionsence compoundssample extracts

r40

Sugar

Ql-¡nhr¡nco

Unknown A

Unknown B

RaffinoseMelibioseUnknown C

Unknor¿n D

LactoseMaltoseUnknor+n E

SucroseUnknown F

GalactoseGlucoseUnknown G

FructoseArabi nose

{YloseMelez i tose*Myo-inositol*Treha lose *

lues relative to fructose, andwith diphenylamine for refer-

and sugars isolat,ed from crude

10

10

10

10

10

10

10

4

4

10

10

i010

i0.L tlj

10

4

AI

R_ X 100T TUC

23

30

35

3B

44

46

53

53

55

6'7

75

B6

BB

B9

100

100

ro4111

Color

Bn

Bn

BIBn

B1

Bn

B1

BIBI-Vt

Bn

Bn

B1 -GyBn-Gy

B1-Gy

Or-BnOr-BnOr

Or-Bn

* no detected reaction wiColors: Bl=blue Bn=brownVt=violet

th diphenylamineGy=grey Or=orange

r47

Fig. 42. Typical chromatogramextract, indicating separationglucose (G), and sucrose (S).

of crude sampleof fructose (F),

143

Fiq.43. Typical chromatogram of soluble sugarsin C. demersum, indicating separation of 7 com-ponents': fructose (F), glucose (C), sucrose (S)

melibiose (M), unknown (hydrolysis product ofstachyose) (u), melibiose/raffinose (¡ln), and

stachyose (St ) .

145

spots also resembled these standards in their separation

sequence, although Rf, values of sugars from crude sample

extracts T{rere consistently higher t.han stachyose, raf f inose,

and melibiose. The second spot from the origin (B) gave a

blue color react,ion and díd not compare well with any of the

reference compounds.

Analysis of NMR spectra (figs. 44 to 56) provided more

detailed information regarding the identity of crude extract

sugars. The major component of spot A was confirmed to be

stachyose in 13c and proton NMR spectra. peaks at 5.31,

4.87, and 4.LO in the proton spectrum matched those of

stachyose. Smal1 peaks at 5.72 and 5.01 indicated the pres-

ence of a minor component. In the 13C spectrum, the 2 c-L

peaks of galactose at gg.2 (t,erminal) and 99.5 (internal)

agreed with values of similar tetrasaccharides. The minor

components did not produce strong siginals in 13c.

Metibiose was detected as the major component in spot

D, using proton spectra. Peaks at 4.55, 4.87, and 5.I2

matched well with the melibiose standard.

NMR analysis provided evidence that spot B rsas a mix-

ture of raffinose and melibiose. In the proton spectrum,

peaks at 4.55, 4.87, and 5.I2 agreed well with t,he standard

melibiose spectrum, representing protons on C-1 of glucose,

C-1 of galactose, and C-1 of glucose. Peaks at 4.08, 4.87,

and 5.30 compared well with raffinose, representing protons

on C-3 of fructose, C-1 of galactose, and C-l of glucose.

All carbons for both melibiose and raffinose could be

r46

assigned in the 13c spectrum. Exact identification of altpeaks was difficult in the 69 to 72 ppm range, as there'r,rere I2-I4 carbons with resonance in this range.

The presence of melibiose in 2 spots (e and D) wiùh

dist,inct R-_ values suggiested that the presence of thisrrsugar in spot B was due to t.ho nerfiat hydrolysis of raf-

f inose .

Spot C, hypothesized to be raffinose in paper chroma-

tography, Çâvê 13c and proton spectra resembling spectra of

stachyose. Doublets at 5.31 and 4.87 and single peaks at

4.IL and 4.09 l/ere in good agreement with the standard spec-

trum of stachyose. Hovever additionat doublets at 5.02 and

4.30 suggest,ed the presence of another component. The 13c

spectrum clearly showed the appropriate shifts for the glu-

cose and fructose components. The terminal galactose and

internal galactose of stachyose were both accounted for in

the spectrum. The R.- of the third spot, however, did notrrcompare l¡ell with that of t,he st,achyose reference. Spot A,

also ident,ified as stachyose in NMR analysis, more closely

agreed with the reference compound in terms of Rfr. The

large R-_ value suggested t,hat ùhe constituent of spot C- rrwas not a tetrasaccharide, although the appropriate con-

stituents of stachyose were present (fructose, glucose, and

2 galactose units). It rÌas hypothesized that the spot con-

sisted of a mixture of hydrolysis product,s of stachyose.

Due to the inconclusive results regarding the identity of

the 4 sugars unique to C. demersum, the sugars vere combined

r47

in subsequent statist,ical analyses.

The content of individual sugars in the macrophytes

during 1985 is shor¡n in Figs. 57 to 74. Regression analysis

revealed the following significant negative relationships of

sugars in leaves and stems with water depth: sucrose in

E. canadensis on July 1O-11 (R2=0.43, p<0.005 , n=2O), fruc-^1/tose (p.L=O.2I , p<0.05, n=24) and glucose (R'=0.19, p(0.05,

n=24) in U. exalbescens on AugusL 29, fructose in P. foliosus

on July 1O-11 (R2=0.19, p<0. OO2, n=50), and sucrose in P.

fo--qsr¿€ on May 3O (R2=0.34, p(0.05, n=72), June 27 (R2=0.53,

p(0.001, n=25), and July 1O-1 I (Rz=O.49, p<0.001, n=50).

Positive relationships with depth were less freguent: fruc-//

tose (R'=0.45, p<0.005, ¡=17) and glucose (R'=0.27, p(0.05,

n=17) in M. exalbescens on May 76, and glucose in P. foliosus

on June 1 3 (Rz=0.38, p<0.005, n=20 ) . Proportions of individ-

ual sugars were also analyzed using linear regression, but

this did not increase the number of significant relationships

with depth.

Seasonal changies of individual sugars in t,he various

macrophytes were examined in terms of proportions of total

soluble carbohydrate. Proportions of sugars (figs 75 to 84)

shor+ed some significant seasonal differences in SNK and

Tukey's tests (labtes 1B to 29). Sucrose was the predominant

sugar for the major part of the growing season in E-. cana-

densis, P. foliosus, P. gramineus, P. praelongus, P. richard-

sonii, P. robbinsii, and P. zosteriformis. The proportion of

sucrose reached levels as high as 72 % in P. foliosus and

t48

E. canadensis on June 13, and 85 % in P. qramineus on

August B.

The most abundant sugar in E. canadensis on all sam-

pling dates in 1985 was sucrose. The proportion did not

change significantly with time, although levels did fluctu-

ate and were highest, on May 30 and June 13. The relative

sucrose content in P. foliosus showed considerable seasonal

variation and exceeded 40 % of total soluble sugars on May

16, June 13, July 10-11, and August B. A significant season-

al maximum in the proportion of sucrose was observed on June

13. Levels of individual sugars in roots and shoots/leaves

were not significantly different in the single P. folÍosus

sample containing roots. The predominant sugar in the roots

was sucrose. The proportions of sucrose also fluctuated with

time in P. robbinsii, with levels being highest on July 10-11

and August B. À significant seasonal increase was observed

in the proportion of sucrose in P. richardsonii, with levels

on July 10-11 and August B exceeding the mean on June 27.

There was also a tendency for a seasonal increase in the

proportion of sucrose in B. zosteriformis, with levels on

July 10-11 being significantly greater than proportional

1eve1s on May 2.

Glucose was the predominant sugar in U. exalbescens

during the init,iat part of the 1985 season. The proportion

of this sugar was found to be significantly higher on May 2

and June 27 than in July and August. The proportion of

sucrose was hiqher than that, of the other sugiars in July and

149

August, and vas significant,ly greater than the proportion

of sucrose on May 2 and June 27. The proportion of glucose

'hras significantly higher in shoots/leaves than in roots on

June 27. No other significant comparisons in sugar content

were observed for M. exalbescens samples containing roots.

Glucose \,¡as the most abundant sugar in N. f lexilis on 2 of

the 3 sampling dates on which this species was represented.

The combined proportion of melibiose, taffinose, and

stachyose in C. demersum accounted for the major proportion

of soluble sugars for all sampling times in the 1985 growing

season. The proportion of these sugars did not show any

significant seasonal differences. Retative amounts of fruc-

tose and glucose in C. demersum frequently exceeded sucrose

levels, and the 2 sugars were often present in similar

quantities.

150

Fig.44. Proton NMR spectrum of Unknown A( stachyose ) .

arrÈÞ r-ÕÕ'rPIPH I08AU PqOG.pgESlt.

û0aTE 4-6-97

sF 300 t3asY tt2 35000000t 5795 r35sI 32768r0 3¿768sr 3906 ¿50HI/pt ¿38pt 80FO 00^0

4 t94R6 100HS I28lE 300

190 05533 ¿36

251 00

LB ¿OO68 600cx 38 00cY 15 00Fl 6 001pF? t 001PHZlcra 39 {90PPA/Cx 13?sc 1 t43 85

:- l--.' t ,

2.1 2 2

(tl

¿l-r--l-¡t.6 t.¡

r52

Fig.45. 13c *"* spectrum for unknown

( stachyose ) .

BEI|GÉL><) ä

PtPC.008AU PROG.

ÞOHSÍOFE AU0ÄTE 23-6-87

sF 75. 469sY 1 12. 35000000t 17000.000sI 32768f0 32768sH I 7857 143HZ/pt 1.0s0

PH 5.0FD O Oa0 .gteBG ¿OONS 10S60TE 3OO

FH 2¿¿0002 5000 000DP 18H BB

La 1 .000GB .700cx 38 00CY BOOFt r10 00lpF2 59 656PH¿lCx 99 985PPT/CM 1 J25sF 38699 49

\¡3-C NHF ^Í

75.47 AHZ

rl úi"¡ "J1lrl

d @{ old--Àl¿fldtffi d dI q rtt snfrn qd

"l "t "Àl -]JJ"J.L¡ J JI I Tt TftTï tl| | ìt \\il/ tl

-!-l-, l-J.1. I J. , L I r I . | . _t- J_ . J_ , _t ', ,t | | , | , | , I .lt , | , If00 eB 96 s4 92 90 88 ra

oo"ro s2 s0 7s 76 11 -1? --lO--Eã----õÈ- 6,. Sa OO

.t "¡"¡I11I lltll

tsLN

r54

Fig. 46. Prot,on NMR spectrum of Unknown

( raf f inose/st,achyose ) .

\r'vP IPH, I07AU PROG.

OFESA f AU0atE d-6-8/sF 300 13{sY 1t2.35000000t 5795 /35s f 32 768f D 32 /68sH J906. ¿50ll|/Pf 238

Pi I 0F0 0 0À0 4 194RG 20N5 128T6 300

FH {90002 5s33 {75OP ¿51 OO

LB ¿OOG8 600cx 38 00cY 15 00Fl 6.004PF2 1 o04PHZ,/CH 39 ¿90PPH/CM I32sR 4 l4J 85

'ii1-H AT 300 r'4HZ

I'P M

H(tlul

156

Fig.47. 13c NMR spectrum of Unknown

( raffinose/stachyose ) .

(><) B[1BEJEÊ :I^1(><) ËsHII

PIPC 507 -2^ú

PAOí-= //OOHSTCNÊ AU '

0afE l7-6-87sF 75 469sY 112 35000000t 47000 000sI 3¿768f0 3?768sr r7857 113ttt/Pf 1.090

PH 50FD OOa0 91eqG 400NS 29¿98rE 300

t

J8l0

10259

000/0000QOI 30Pi96Pû/0t2549

ddddffidN

1 "rÌ -t "l-î"fi.rïfffì't q Isl!ffrlddffidd"t Tt I l]tRifiTll T r| \t | |\\\\//// | I

J__.-__1_:..-_[_-J..__I . r, I . I . I . l, l, I, ¡ . I, l, l, |, I,J l' l-loo 98 96 q¡ 92 90 88 86 8{ Ua

oo, UO 78 76 74 72 70 68 66 6¡ 62 60

(,\]

l5B

Fiq. 48. Proton NMR spectrum of Unknown C.

BflIEF IcK) ä

pfpH t06AU PR06Þn€s^f Au

0AIE 4-6-87

sF 300. t3asY rr¿ 15000000r 5t95 r35sI 3¿768T0 32768sr 3906 ¿50ÊI/PÎ ¿38

Pt 00F0 0oA0 4 t94Âb 20NS t2€fÉ 300

190 05f33 4 75

25L O0

L0 ¿00GB 600LX 3e 00cY 15 00Fl 6 001pF2 I 004pH¿lCX 39. 490pPx/cx t32sq 1ta3 85

\r v

t-rt lt 100 xH¿

tsLN

160

Fig.49. 13c ttiun spectrum of Unknown c.

sF 75 .69sY t t2. 35000000t .7000 000sI 32¡68TD f?768sr 17857 143HZ/Þf I OCo

Pl 50q0 00AO 9t6nG 100NS t0¡3?I€ 3OO

Ft 22.000¿ 5000 000DP t6h 8S

L8 r 000G8 700cx 38 00cY I 00Fl r0¿ l30PF2 59 J96pHZICH 8. €,/0PPX,/CH t 1253q 38699 19

t3-c ?{H8

ddììtlllfr Efrffiffiffi ãsï ffiffïrñTrffiï fir/ | lr \\r/ \\/\t/ | |

Til TT1

TN TN\r v/

HOt

762

Fiq.50. Proton NMR spectrum for Unknown D

(melibiose).

HoìC^)

t-H AI 300 tHZ Ir,t 020

gf,rEq I(><l Ë

P¡PH I05AU PPOG

PnESA f au0AlÉ a-6 67

sF 300 t3.sY tt? t5000000t 5795 r35sI 32)68l0 32768sr 3906 ¿50HLlPt ¿38

Fr a900o? 5533 ¡r5oP 251 00

PIAOAO

NSf€

L8 20068 600cx 38 00cY t5 00Ft 6 00.PÊ? I 00¡pH¿ICX 39 490PPr/Cx 132sB 4la3 €5

164

Fiq. 51. Proton NMR spectrum of melibiose.

'¿x5' ñ

PtPH.002AU PqO6

PFESAÍ Û0¡lÉ ?2-a-87

sF 300 t3.sY tt?.3ã000000t 5795. 735sI 3?768t0 32768s, 3906 ¿50xzlPt ?10

Pr 80F0 00À0 . lgaAG 320NS le8IE 3OO

Ff a900oa ã533 236op 25L 00

Lg IOO68 600cx 30 00cY 15 00F! 5 6t6ÞF2 55?PH¿ICX 39 998PPrlca t33sR at.s 07

XELIBIOSE t-H Î

3OO IHZ

t Oì(¡

166

Fiq.52. Proton NMR spectrum of raffinose.

Bf,IEÞ '(x) Ë

PI9H OO3AU PR06.ÞnÊsAf {rJ

0ATE ¿2-1-87

9F 300 13¡sY tl¿ J5000000r 5r95 r35sf J¿768r0 3¿r68st 3c(r6 ¿50HL/pt ¿t8

Pl eoc0 o0A0 4 lq48G 160{s l¿0IE JOO

Ft 4900o¿ 55.ìJ 2J6DÞ 2.'tt 00

L8 10068 ô00cx J8 00cY 15 00Fl 5 6r6PF¿ 552Þh¿lcx J9 998Ppt/Lx tijsn 4145 0t

'ì "l't"'llttl1'ttltl

?e---¡'?¡--l¡'-1¡---i¡---r;*ì¡.- i"' * -. b

or{

168

Fig. 53. Proton NMR spectrum of stachyose.

s+È

¡l?93

5 gB

l ;ã

Bà3

r rg

ãegs

qt\ \o

!'

:9-

Ès¿

.--

-s$t

si,

à 3

oõB

-B

B 3

ts3'

.. 33

8333

ãÞóJ

OO

oO-

Ñ

:ao

Þru

!O

-iB

Bså

õ"8:

HÊ

Hgg

ET

ÛE

I "È

l;r

*åtr

å' 'ô

F

3 63

06

3 1a

8a

697

L70

Fig.54. 13c NMR spectrum of stachyose.

","".F" uî

rU PR06 /-ÞorsloÊF Ar,o^fE ¿9-{-873F 75 .69sY tt2 J5000000t .7000 000sI 32/66lo 32 768s: l ra.t/ t{JH¿/9f I 090pi 50n0 00A0 9t8nG .00NS t ¡938rE 300

Fr 2¿4000¿ 5000 0000p l6H 00

LB t 00060 ,f00cx t8 o0cY t? 00Ft rl0 00lPF ¿ 5C btbÞH¿ILB qq C85PPIILX I J¿5sc Ja699 .S

sfacHYosE r3-c NtaR ll 75.a7 t{Hz

I q i q q*sËiffiffi:; ;31 'ì 11 flffiffi iìI I | | \t/v// ll:ir:tll\l

{

772

Fig. 55. Proton NMR spectrum of tactose.

adrÈo-(>Õ' Ê

PfPh oorAù PAo6

oqESA f ^rJ0^r€ ¿¿ 1 87

SF JOO IJ4sY tt¿ J500000Ol 5/g5 rJ5sI J¿rô8f0 J¿/b8sH .lco6 ¿50ttl lP | ¿ r0

c0 0 0Â0 { tq4

NS l¿0If JOO

ç I 190002 55rl ¿JbDP ¿5L OO

L8 100GB b00LX J8 00Lf 15 0oFl 5 6lbPF ¿ 55,1pHllLÈ Jq ccoppa/LA lli

'fl 11.rTl]I TTJÏ1V WV

ì' .,___l_3a __tll_t_--r__tJ | .-l .¿ 50 4I 4 b 4 4

___t_, I ¡,l i4 ¿ 4.0 31 3 6 3.¿

\ì

174

Fig.56. Proton NMR spectrum of myo-inositot.

-^:^" ñt/"'\-)P ÍPtt 00q

sF .ro(, t i4S/ | l¿ -r5(r0('f('0l 5/q.r /.,rs I l.t th8r0 J¿ /bü.iH .rq0t, r.¡ì{,tttlÞ |

.t{¡AO

¡t,iII

II

I

LB ,r('(,LB r,('('r, { .iù ct,

É I lr (,(r(,r)r:J I ( (,1r,tr¿/1,4 r'r 4,tt'rtp{/t.\ I i,isrì 4144 t ,

'xYo-lflosftoL' t-H AT 3oO HH¡

lil,l|í

!t¡

t76

Fig. 57 . Fructose content in stems and leaves of

Ceratophyllum demersum on various sampling dates during

the 1985 growing season. Vertical bars represent stan-

dard error and numbers beside circles indicate sampling

sites. Depth ( in met,ers ) f or each collect,ion time is

shown on the horizontal axis.

H{{

{'l"

{"

{,,

23456A29

{.

CERATOPHYLLUM DËMERSUM

267A8

ï

T'T iTå,, 1 t'@zI{&zr flt

å123

456JY 10-11

2

¡ñzz

t.12 5

JN13-

14

:l1Á(tf.¡tâc!roo

Þ3gtÉ

äooÞ():fffo

3166M16

ä-

I

I

À

o

it.'-' i:¡!;:¡', '. 11

i

r7B

Fig. 58. Glucose content in stems and leaves of

Ceratophyllum demersum on various sampling dates dur-

ing t,he 1985 growing season. Vertical bars represent

standard error and numbers beside circles indicate sam-

pling sites. Depth (in meters) for each collection time

is shown on t,he horizontal axis.


12

i(',

åroo()Jfl

5al¡J A(,

E

¡e

{

,þ" j

&*ta" 0zLr $r

1

1

T

I

T

1I1'

I'

34 5 6

M16

{

f.

{'

12 5

JN13

1.,1$'

2

JN 27

458JY 10-11

I

+"t267

ag

{

Þ'

180

Fig. 59. Sucrose content in stems and leaves of

Ceratophyllum demersum on various sampling dates dur-

ing the 1985 growinq season. Vertical bars repre-


cate sampling sites. Depth (in met,ers) for each col-

lection time is shorr¡n on the horizontal axis.

Þ'

{"

{,'

23456A29

j.

l_{-1{.


267A8

lî'_

+.I

{'

456JY 10-11

J_t23

J,.

2

JN 27

Tqer&rl-'r Sa

,

TEoL¡ttc3sJ

8¿Þf

U'"oÉ,avr2

x25JN13

{

3466M16

t,I&2

2345M2

1

o

T82

Fig. 60. Fructose content in stems and leaves of

Elodea canadensis on various sampling dates during

the 1985 growing season. Vertical bars represent

standard error and numbers beside circles indicate

sampling sit,es. Depth (in meters) for each col1ec-

tion time is shown on the horizontal axis.

l""?t

ITItll*

I'(,

$'

@'

ELODEA CANADENSIS

JV 10-11

{'

{' Þ,

T14(ttd(t,

U312(J

fr¡ lot(JE

l¡¡ I@o!-o3ê¡!lr

I

JN 27

{,

14

JN13

{-

1

M30

3 413M16

123M2

t84

Fig. 61. Glucose content in stems and leaves on

Elodea canadensis on various sampling dates during



sampling sites. Depth (in meters) for each collec-

t,ion time is shown on the horizontal axis.

i B5

ï''

1

ï"

l'ï

ELODEA CANADENS¡S

I

II

$'14 1

JN13 JN27

tt^

.¡6tt'

L)'Ð

I

U5

:)ãq

E3

1

M30

3 413M16

23M2

186

Fiq. 62. Sucrose content, in stems and leaves of

Elodea



canaoens I s

sampling sites. Depth (in meters) for each collec-

t,ion time is shown on the horizontal axis. A statis-

tically significant relationship betr¿een depth and

sucrose content is shown for July 10-11.

on various sampling dates during

ELODEA CANADENSIS

2AT

f¡lIA

?ztÐJ

ìBeok¡

¿

16lrJU'oú,o12f,Ø

TI'o 1'

{.

?2

T-"?{"*l

I'

3 413M16

o3

114 1

M3O JN13 JN27

$z

2 3 413JY 10-11

-J

] BB

Fig. 63. Fructose content in stems and leaves (closed

circles) and roots (open circles) of Myriophyllum

exalbescens on various sampling dates during t,he 1985

growing season. Vertical bars represent, standarC. error

and numbers beside circles indicate sampling sites.

Depth (in meters) for each collection time is shown on

the horizontal axis. Statistically significant re-

lationships between depth and fructose content are

shown for May 16 and August 29.

\oIl'1¡

Y

6

11"

i'T.TI'

f.(Di

l,'

1234A29

MYRIOPHYLLUM EXALEESCENS

L.

r'r' {.

ï

?

23

[email protected]

t'

1234JY 10-11

16

T

å'Tl9'; -!.

I(J

f¡Jtt

L)ÐJ

ol¡J

E

t¡fØot-()fæ,t¡.

ðs

12JN27

Þ.' p<.005

12

1

JN132345

M16

I

c

23M2

1

AP27

190

Fig. 64. Glucose content in stems and leaves (closed


exalbescens on various sampling dates during the 1985

growing season. Vertical bars represent standard error


Depth (in meters) for each collection t,ime is shown on

the horizontal axis. St,atistically significant re-

lationships between depth and glucose content are

shol¡n for May 16 and August 29.

(o

ï'I'

ï'fT,,

{za s,.05

1234A29


{'.

2346A8

3ï

| )zza-Iz1

I"

o23J-

l'þ'o. II

11'

l-

234JY 10-11

{'

1,.

i,'

12JN 27

I22

I

Tou¡U,oo3Joo=

1

JN 13

p .05

2345M16

I

6

4

2

M21

AP 27

L92

Fig. 65. Sucrose content in stems and leaves (closed


exalbescens

growing season. Vertical bars represent standard error


Depth (in meters) for each collection time is shown on


on various sampling dates during the 1985

ç(,

ï'

I

T.

7',

1"

ï'

l.

{:ri"

23429

þ,ï"tÎ'1"


A8

1,, I'

ï= {'

T23oT23

þ[Os

234JY 10-11

16

14

12

10

l.

I

v)

(JÐI

a-ì

12JN 27

I,

1

JN 13

11,

I

6

4

2

o34M16

t,

l¡JU)o(EC)fØ

123AP 27 |12

\94

Fig. 66. Fructose, glucose, and sucrose content instems and leaves on Naias flexilis at sampling site3 during the 1985 growing season. vert,ical bars re-present standard error. Depth ( in meters ) for each

collection time is shown on t,he horizontal axis.

195

NAJAS FLEX.ILIS

10

Ie8V)

Ue6Jrl

)x4flF¿.

1.75

42915

A81

JN 27

196

Fig. 67. Fructose content in stems and leaves (closed

circles) and roots (open circles) of Potamogeton

f oliosus on various sampling times during the 1985 groÌ,¡-

ing season. Vertical bars represent st,andard error and

numbers beside circles indicate sampling sites. Dept,h

(in meters) for each collection time is shor,¡n on the

horizontal axis. A statistically significant relatÍon-

ship between depth and fruct,ose content is shown for

July 10-11.

'.o{

ï¡¡nI

tI

å.

{e

t,'u Îu

ö;M

ð

.0


A8

ltIlTI'r

3456JY 10-11

&'ç,rð.

lttt'^.

LT

3n

æ

uAtt)

(J_J

dzoì:Jr-' 16

¿

r, 12U'ot-orBCEl¡.

4

345JNZI

{'

458JN13

I,?,

456M30

eþ

355M2 M16

198

Fig. 68. Glucose content in stems and leaves (closed

circles) and roots (open circles) of Potamoqeton


growÍng season. Vertical bars represent standard error


Dept,h (in meters) for each collection time is shown on

the horizontal axis. A statist,ically significant re-

lationship between depth and glucose content is shown

for June 1 3.

(o

Tt

?*¿T?6

T

,, t,

'?s T6

67A8


{'

J1'

3456JY 10-11

þt 'Qe

345JN 27

€)r

åIlu't

T'

.{

pz

ð'ung,

x

xtI

f¡ì14lC()Ð-lfì(JE

I

I

o

{'

15¿xrg

56M30M16

3sM2

200

Fig 69. Sucrose content in stems and leaves (closed

circles) and roots (open circles) of Potamogeton


growing season. Verticat bars represent sùandard error

and numbers beside circles indicate sampling sites'

Depth (in meters) for each coltection time is shown on

the horizontal axis. St,atistically significant rela-

tionships beLrrreen depth and sucrose content are shown

for May 30, June 27, and JulY 10-11.

Þ.J

H

{.,

rï'

ï

fII.''åTôret T

"w

ï'

PorAmocETÖr rot¡ogus

{q.

IT'601

{,.

p<.001

*.*1,

T'

{'

h,

T

{.ITtt

+1

p(.001

I

'd &lv)

fdB

Éx

tr,

{'

p<.05

t¡¡at

86ofan

12

{,

456M30

5

M16

35M2

202

Fig. 7O. Fructose, glucose, and sucrose content in

stems and leaves of Potamoget,on qramineus at station

22 on various sampling dates during the 1985 gror+ing

season. Vertical bars represent standard error.Dept,h (in meters) for each collection time is indicated

on the horizontal axis.

203

POTAM OGETONGRA MI NEUS

I

r-ì 20U)

UÐJ16L,

912r-¿.

3

AB

32JN 13 JN 27

204

Fiq. 7I. Fructose, glucose, and sucrose content in

stems and leaves of Potamoqeton praelongus af a depth

of 2 m during June of the 1985 growing season. Ver-

Lical bars represent standard error and numbers beside

circles indicate sampling site.

205

POTAM OG ETO N

PRAELONGUS

Tr.

1'

I

U)

UJ

rl

25

20

I

f

å

Þzg

*

*FJ- 22

TIIG

oFJ-

^t-L

22JN 13 JN 27

206

Fig. 72. Fructose, glucose, and sucrose content in

stems and leaves of PoLamogeton richardsonii on various

sampling dates during t,he 1985 growing season. Verti-

ca1 bars represent standard error. Collection sites,as indicated, were 3, 22, and 23. Depth (in met,ers)

for each sampling time is shown on the horizontal axis.

201

POTAMOGETONRICHARDSON II

I

u-)

UÐJ

Þof-r

30

25

20

21.52JN 27 JY 10'11 A B

208

Fiq. 73. Fructose, Çlucose, and

stems and leaves of Potamogeton

sampling dates during t,he 1985 growing season. Ver-

tical bars represent standard error and collection

sitesr âs indicated, were 3, 5, and 9. Depth (in

meters) for each sampling date is shown on t,he hori-

zontal axis.

sucrose content in

robbinsii on various

209

BINSIIROB

^ô.

I

I

I

POTAMOGETON

Tc

i.I

ï+1t-Ti?

I

I

III

ïI

II1

îI

o.ô.

I

oI

I

^^

II

v12Ø

U

=10ìÐg8

¿.

I,10

,Tor.I

1.75

A29

1.5

AB

1.5 5JY 10-11

51M16 JN27

210

Fiq. 74. Fructose, glucose, and sucrose content in

stems and leaves of Potamogeton zosteriformis on vari-

ous sampling dates during the 1985 growing season.

Vertical bars represent standard error and numbers be-

side circles indicate sampling site. Depth (in meters)

for each collection time is shown on the horizontal

axis.

ZOSTERIFC'RMISPOTAMOGETON

I IÏ.

I"tr+"1

îIIT

* ft'III

T

Ø

IJ

zl4

lrl.no

-r-O_l tt.^ I u,taa IreÇ{e

-l- |

tlOTI¡ltörI

I


t'

34õJY 10-1r

234JN 27

f"

3M2


{'

T, zs

3zo

5o-ls

I'ðr-22

3M2

-30

32sJ

?,9202

P15oF()fG10L

345JY 10-11

3234M2 JN27

2r2

Fig. 75. Proportions of soluble sugars in stems and

leaves of Ceratophyllum demersum on various sampling

dates during the 1985 gror.ring season. Vertical bars

represent standard error. Dept,h ( in meters ) for each


I Fructose

E Glucose

ffi sucrose

E uer ibi ose,/Raf f inose/Stachyose

cî'{N

rnE|at ¡ttu¡rþEE

2I4

Fig. 76. Proportions of sotuble sugars in stems and

leaves of Elodea canadensis on various sampling

dates during the 1985 growing season. Vertical bars

represent standard error. Depth ( in meters ) for each


L Fructose

E Glucose

&ü sucrose

PE

RC

EN

T S

OLU

NLE

C^R

BO

HY

DR

ÀT

E

t- õ z¡ t- ì

ln o fi o z o ñ z I g,

¡ Ê t¡

çÍz

2r6


leaves of Myriophyrlum exalbescens on various sam-

pling dat,es during the 1985 growing season. Verti-

ca1 bars represent standard error. Dept,h ( in meters )

for each collection time is shown on the horizontal

axis.

i- Fructose

E Glucose

W sucrose

PE

RC

EN

T

TO

TA

L S

OLU

BLE

CÀ

RB

OH

YD

RÀ

TE

Ã r - 3 m - Ð m ø m 2

2I8


leaves of Na'ias f lexilis on various sampling dates


present standard error. Depth ( in meters ) for each


I-.- Fructose

ß Glucose

ffi sucrose

c- z¿ N

PI.]

RC

I.]N

T S

OLU

BLE

CÂ

RB

OH

YD

RA

TE

88È

sR

>..

€o (,

r

Þi 8d

z Þ c- Þ (t, 'n m x r U)

N)

(o

220


leaves of Potamoqeton foliosus on various sampling

dates during' Lhe 1985 growing season. Vertical bars



I Fructose

ffi Glucose

&l sucrose

o { Þ 3 o m o z o r õ ø g,

PE

RC

EN

T

TO

IAL

SO

LUB

LE C

AR

BO

HY

DR

ÀT

E

¡q z N t)

c o h à

g <¡

6q É

q o

oo ¿

r

222

Fiq. 80. Proportions of sotuble sugars in stems and

leaves of Potamoqeton gramineus on various sampling




I Fructose

Ð Glucose

K sucrose

i\) f.J UJ

! o I =. o o m { o z 6) , =z m c q,

PE

RC

EN

T S

OLU

BLE

CA

RB

OH

YD

RA

TE

C. 3s

t(Ð C

. (' Icr

221

Fig. 81. Proport,ions of soluble sugars in stems and

leaves of Potamogeton praelonqus on June sampling dates

during t,he 1985 season. Vertical bars represent stan-

dard error. Depth (in meters) is shor¿n on the hori-

zonLal axis.

I Fructose

ñ Glucose

K sucrose

225


60

ttç*L

U

.ì

J(n

Fzr)

50

40

30

20

2

JN 13

2

JN 27

226


leaves of Potamogeton richardsonii on various sampling

dates during t,he 1985 growing season. vertical bars

represent standard error. Dept,h ( in meters ) for each

collection t,ime is shown on the horizontal axis.

! Fructose

fi Glucose

ffi sucrose

N) t! {

! o t 3 o o frl { o z ¡ o - Þ :o (] U' o =

PE

RC

EN

T S

OLU

BLE

CA

RB

OH

YD

RA

TE

c Z¡¡

Ì\) I ir,

Þ o1\,

228


leaves of Potamogeton robbinsii on various sampling

dates during the 1985 growing season. Verticat bars


collection time is shown on the horizonLal axis.

I Fructose

fr Glucose

ffi sucrose

229

POTAMOGETON ROBBINSII

U

=

-z

5

M16 JY 10-11

1.5

A8

¿5U


leaves of Potamogeton zosteriformis on various sampling




I Fructose

fl Glucose

ffi Sucrose

Ë

c¡)

PE

RC

EN

T S

OLU

BLE

CA

RB

OT

IYD

RA

TE

ÌÙG

)è(¡

o)oo

ooo

T o { Þ 3 o o m { o z N o Ø { m TJ

.Tl o 7 =U)

N)

Table 18. Signifícant differences in proportionsof ethanol-so1uble sugars in Q.demersum duringthe 1985 season . 2=I4y 2 3=l4y 16 5=Jn 13 6=Jn 277=Jy 10-11 B=Aug B 9=Aug 29

ZJ¿

FRUCTOSE

DATE N

z556

B

9

112510

295

T1

MEAN

.267 1

.2287

.2132

.2990

.3454

.27 34

.2304

GLUCOSE

GROUPINGòt\ r\

1l . ù .

n.s.ll . ù .

n.s.n. s.n.s.tl . ò .

DATE N

z3567B

9

112510

z95

L7

MEAN

.1937

.r799

.1898

.2002

.2156

. IB97

.1678

GROUPINGTUKEY'S

n.s.n.s.nc

rt . ò .

n.s.n. s.tr . Þ .

SUCROSE

GROUPINGSNK

n. s.n. s.n. s.rl . ò .

n.s.n.s.n. s.

DATE

23567a

9

N

112510

295

T7

GROUPINGTUKEY'S

MEAN

0650I4400960049 1

oB24II62r407

n.s.n.s.n.s.It . ù .

n.s.ll . ù .

n. s.

GROUPINGSNK

nh

nnnnn

S.S.S.ù.S.Ð.Ð.

GROUPINGTUKEY'S

39L

n.s.n.s.n.s.n.s.1

Tab1e18.(Cont.)

MEL I B ] OS E/RAFF I NOSE,/STACHYO S E

DATE N MEAN GROUPINGSNK

aL

356

09

233

112510

295

I'7

.4'7 42

.4473

. 5009

.4517

.4207

.46rO

lI . Þ .

n. s.lr. Þ .

n.s.n.s.n.s.n.s.

GROUPINGTUKEY'S

n.s.n. s.na

n.s.n.s.n.s.n.s.

Table 19. Significant differences in proportionsof ethanol-so1uble sugars in Ð.Ce¡e_d_eISiE duringthe 1985 season. 2=l4y 2 3=NIy 16 4=þIy 305=Jn 13 6=Jn 27 j=Jv 10-11

FRUCTOSE

114

DATE N

2937445363720

MEAN

.3737

.2800

. IT2B

.1143

.37 37

.3284

GLUCOSE

DATE

GROUP]NGSNK

2937445363720

I

n. s.26744I

MEAN

.2926??qn

.1814

. i015

.2390

.2026

GROUP]NGTUKEY'S

A

ne

267n.s.44

SUCROSE

DATE

GROUPINGSNK

n. s.n. s.n. s.n. s.Il . ù .

ne

2931445363720

MEAN

.3937

.4999

.7058

.7 242

.3873

.4690

GROUPINGTUKEY'S

n.s.n.s.rl . ò .

n.s.n.s.n.s.

GROUPINGSNK

II . ù .

n. s.n.s.II . ò .

n. s.

GROUP]NGTUKEY'S

n.s.n.s.n.s.tt . Þ .nq

n.s.

Table 20. Significant differences in proport,ionsof ethanol-so1uble sugars in M.exalbescens duringthe 1985 season. 1=Apr 27 2=NIy 2 3=l4y 165=Jn 13 6=Jn 27 7=Jy 10-11 B=Aug B 9=Aug 29

FRUCTOSE

235

DATE N

1

2356a

Õ

I

516T7

J15201521

MEAN

2548305327 43TB494163297635193516

GLUCOSE

GROUPINGSNK

6n.s.n.s.68915n.s.55

DATE N

'lf

¿

35

R

o

J

1611LT

31520152T

GROUPINGTUKEY'S

tr . Þ .

n.s.663576rl . ù .

tr . Þ .

MEAN

38965r62355846514959290026002690

SUCROSE

GROUPINGSNK

DATE

789n.s.789789256256256

1

2356a

Õ

9

N

51677

31520152I

GROUPINGTUKEY'S

MEAN

tt . Þ .

37¿

n. s.7B262626

3556178536993 500o87 941243BB13920

GROUPINGSNK

26

B9

1352626135zo2626

7-9

7-9

GROUPINGTUKEY'S

6

¿on.s13262626

-9

7-9

Table 21. Proportions of sugars in rootsand shoots/leaves of U.exalbescens during the1985 season. Means with the same letter werenot significantly different, as determined inSNK and Tukey's tests at alpha=O.05.

236

FRUCTOSE

DATE

June 27

August B

August 29

9

69

¿

6

GLUCOSE

DATE

June 27

August B

August 29

T I SSUE

RootsShoots/leavesRootsShoots/leavesRootsShoots/leaves

MEAN

.4381

.3838

.367 2

.3108

.3486

.3520

59

6I

6

SUCROSE

TISSUE

RootsShoots,/leavesRootsShoots/leavesRootsShoots/leaves

DATE

June 27

August B

August

f\

¿t

7\

A

ön

MEAN

.3718

.5259

.2895

.2634

.3013

.3870

59

69

¿

TISSUE

RootsShoots,/leavesRootsShoot,s/leavesRootsShoots/Ieaves

ðR

A¡\

ää

MEAN

. 1901

.0903

.3434

.4258

.2T87

.26rO

.É\

nö

åå

ðft

Tabl-e 22. Significant differences in proportionsof ethanol-soluble sugars in N.flexilis duringthe 1985 season. 6=Jn 27 B=Aus B 9=Aus 29

237

FRUCTOSE

DATE N

6

9

233

MEAN

. 3169

.3608

.28BO

GLUCOSE

DATE

6B

9

GROUPINGq ÀTI¿

NQ

n. s.NQ

L

33

MEAN

.5738

.3298

.5450

SUCROSE

DATE

GROUPINGTTTI¿E'V I Q

NQ

n.s.

6B

9

GROUPINGSNK

MEAN

.1093

.3094

. r670

233

B

69B

GROUPINGTUKEY'S

GROUP]NGSNK

B

69B

B

66

GROUPTNGTUKEY'S

NQ

n.sn.s

Table 23. Significant differences in proportionsof ethanol-so1uble sugars in !.foliosus duringt,he 1985 season. 2=l4y 2 3=l4y 16 4=I{y 305=Jn 13 6=Jn 27 1=Jv 10-11 B=Aus B

FRUCTOSE

¿3ö

DATE N

23/1-56-B

IX

10T221195011

MEAN

.3609

.2288

.42r3

. r409

.3339.2070.27 6r

GLUCOSE

DATE

GROUPINGSNK

23456.-|

B

N

1B10T22I195011

3572 4-63 5-B2-4 6

246245

8

MEAN

.3368

.2019

.3354

.1385.2959. 194T.299r

GROUPINGTUKEY'S

B

3572435782468

24645

SUCROSE

DATE


2

456-7

B

N

1B10I22T19qn

1i

357246357¿4b3s7246357

MEAN

.3023

.5694

.¿453

.7 206?7n?

.5989

.4248

H

3572435724657¿4057

GROUPINGSNK

35724-682Â.4J J_A

2-4 6-83-5 724-683-5 7

B

B

GROUPINGTUKEY'S

357246357246-835724-6857

239

Tab1e24. Proportions of sugars in roots andshoots,/leaves of P. f oliosus during the 1985season. l4eans with the same letterh¡ere notsignificantly different, as determined inSNK and Tukey'S tests at alpha=O.05.

FRUCTOSE

DATE

June 27

GLUCOSE

DATE

June 27

TISSUE

RootsShoots,/leaves

SUCROSE

DATE

June 27

TISSUE

RootsShoots/leaves

MEAN

.3268

.37 r9

TISSUE

RootsShoots/leaves

óó

MEAN

.246r

.3158?\

n

MEAN

.427 r

.5I¿5äA

Table 25. Significant differences in proportionsof ethanol-soluble sugars in P.gramineus duringthe 1985 season. 5=Jn 13 6=Jn 27 B=Auq B

21,O

FRUCTOSE

DATE N

56B

356

MEAN

.2450

.352r

.0659

GLUCOSE

DATE

GROUP]NGSNK

56I

6B5B56

356

MEAN

23223I4IoB23

SUCROSE

GROUPINGTUKEY'S

DATE

GROUPINGSNK

B(t

56

5

ö

B

56

5

^

MEAN

.5229

.3338

.8518

GROUPINGTUKEY'S

GROUPINGSNK

B

ö56

6B5856

GROUPINGTUKEY'S

6B5B56

24I

Table 26. Significant differences in proportionsof ethanol-so1ub1e sugars in !.praelongus duringthe 1985 season. 5=Jn 13 6=Jn 27

FRUCTOSE

DATE N

15

MEAN

.247 2

.3689

GLUCOSE

DATE N

15

GROUPINGSNK

MEAN

.2624

.3136

65

SUCROSE

DATE

GROUPINGTUKEY'S

566 15

GROUPINGSNK

65

6

MEAN

.4904

.3175

GROUPINGTUKEY'S

GROUPINGSNK

65

65

GROUPTNGTUKEY'S

65

242

Table27. Significant, differences in proportionsof ethanol-soluble sugars in !.richardsonii duringthe 1985 season. 6=Jn 27 1=Jy 10-11 B=Aug B

FRUCTOSE

DATE

67B

2

5

MEAN

.6308

.2576

.1393

GLUCOSE

DATE

GROUPINGSNK

67B

ló6B67

265

MEAN

.3186

.2087

.1803

SUCROSE

GROUPINGTUKEY'S

DATE

GROUPINGSNK

n.s.n.s.n.s.

7B6B67

67B

)¿65

t'l,D Étlv

0507'53976804

GROUPINGTUKEY'S

n.s.n.s.n.s.

GROUPINGSNK

7B66

GROUPINGTUKEY'S

/ó66

Table 28. Significant differences in proportionsof ethanol-soluble sugars in P.robbinsii duringthe 1985 season. 3=My 16 6=Jn 27 7=Jy 10-11B=Aug B 9=Augi 29

243

FRUCTOSE

DATE

3h

7B

9

66oÃ

6

MEAN

.2815

.3572

.2790

.27 r2

.4384

GLUCOSE

DATE

GROUPINGSNK

367tt9

91

6993tB

6696R

MEAN

.2667

.4132

.23r4

.1599

. 3150

GROUPINGTUKEY'S

SUCROSE

DATE

97699

GROUPTNGSNK

3

7Bo

6378669B

6R

Y

6

MEAN

.45L9

.2296

.5496

.5689

.2466

GROUP]NGTUKEY'S

n.s.7B669U

GROUPINGSNK

6937696937

GROUPINGTUKEY'S

69<t

696937

244

Table 29. Significant differences in proportionsof ethanol-soluble sugars in P.zosteriformisduring the 1985 season. 2=NIy 2 6=Jn 27 1=Jy 10-11

FRUCTOSE

DATE N

2106772r

MEAN

.2549

.2519

.2334

GLUCOSE

DATE N

GROUPINGSNK

n. s.n.s.NQ

2r06772r

MEAN

.3164

.2350

.2100

SUCROSE

GROUPINGTUKEY'S

n.s.ne

n.s.

DATE N

GROUPINGSNK

2ro6772r

67aL

2

MEAN

.4287

.5131

.5566

GROUPINGTUKEY ' S

GROUPINGSNK

7n.s.2

1ne

GROUP]NGTUKEY'S

-n.s.2

¿¿l3

E. Effects of environmental variables

a" Correlation analysis

correlation analysis lras performed for soluble carbo-

hydrate, starch, fructose, glucose, and sucrose content inq. demersum, E. canadensis, M. qê_lÞg_q-qg_rìS, p. foj-iosus, and

P. zosteriformis. Time, dept,h, 1ight, and pH were included

in the analysis (tabtes 30 to 34). Environmental parameters

corresponding to collection sites and times for t,he 5 spe-

cies (Table 35) revealed a significant negative correlationbetween depth and light (r=0.65, p(0.001, n=30) (taure 36).

In Ç. demersum, E-. eanadensis, and E. foliosus, soluble

carbohydrate, starch, and individual sugars were negativelycorrelated vith depth. Negative relationships with dept,h

were also observed for staråh, fructose, and glucose inP. zosterifornis and for starch in M. exalbescens.

Soluble carbohydrate, starch, and individual sugars

l¡ere positively correlated with light in e. demersum and

P. foliosus sith a significant (¡=Q.66, p<0.05, n=10) rela-tÍonship betreen f ight and sucrose in C. &me¡Sgm. The 5

parameters ryere negatively correlated with tight in M. exal-

bescens.

In e. demersum, soluble carbohydrate, starch, and índi-vidual sugars were negatively correlated r¡ith pH. E. cana-

densis and M. exalbescens had negative relationships between

st'arch and pH and posit,ive relationships wit,h pH for soluble

carbohydrate and the 3 sugars. soluble carbohydrate and su-

crose were each negatively correlated with pH in p. foliosus

246

and P. zosteriformis, while starch, fructose, and glucose

were positively related to pH. In P. zosteriformis, the

negative carbohydrate - pH relationship (¡=-0.70, p(0.05,

n=10) and the positive correlation between starch and pH

(r=0.80, p(0.05, n=6) were significant.

Starch was negat,ively correlated with time for e.. demer-

sum and E. canadensis. The relationship was significant for

g. demersum (r=-O.'7I, p<0.05, n=I2). Total soluble carbohy-

drater orr the other hand, had a positive relationship with

time for these species. In P. zosteriformis, starch was

marginally significant,ly positively correlated wit,h time

(r=0.81, p=0.05, n=6), and t,his relationship was also posi-

tive for M. exalbescens and P. foliosus. Total soluble car-

bohydrate was negativellr correlated wit.h time in these 3

species.

Fructose and gilucose were each negatively correlated

with time in E. canadensis, M. exalbescens, P. foliosus, and

P. zosteriformis. This seasonal trend was signíficant for

both suçJars in P. foliosus (fructose r=-0.68, glucose

r=-0.66, p(0.02, n=13), and for glucose in P. zost,erifqrmis

(¡=-1 .0, p1O.02, n=3 ) . Fructose was negatively correlated

wit,h time in C. demersum. The relationship between sucrose

and time was positive in Q. demersum, M. exalbescens, and

e.

P.

zost,eriformis and negative in E. canadensis and

fol iosus .

Carbohydrate and starch were negatívely correlated for

atl 5 species. Carbohydrate was positivel-y correlated lrith

247

fructoser glucose, and sucrose in E. canadensis, U. exal-bescens, and P. foliosus, with fructose and glucose in

e. demersum, and with sucrose in p. zosteriformis. of these,

significant relationships vere observed for fructose inÇ. demersum (r=0.86, p<0.005, n=10), glucose in M. gxalþCsqCns

(r=0.65, p 0.05r n=10), and sucrose ih e. foliosus (r=0.60,

p(0.05, n=13 ) . Negative relationships h'ere f ound betl¡een

carbohydrate and fructose and glucose in p. zosteriformis.Fructose was significantty posit,ively correlated with

glucose in 9. demersum (r=0.84, p<0.005, n=10), E. canadensis

(¡=0.92, p<0.005, n=7)r âDd P. foliosus (r=0.98, p<0.001,

n=13). Positive relationships betr¡een fructose and grucose

rrere also found in M. exalbescens and p. zosteriformis.Fructose and glucose were each posit,ively related to sucrose

in c. demersum and u. exalbescens, and each of the 2 sugars

was negatively related to sucrose in p. foliosus and p. zos-

teriformis.

b. Stepwise analysis

Relationships between met,abolic parameters and environ-

mental factors rrere furt,her studied in c. demersum, E. c-anê-

densis, M. exalbescens, P. foliosusr and p. zosteriformis

using stepwise multiple regression (fables 37 and 38).

with respect to soluble carbohydrate contentr tro varíables

met the 0.15 significance level for entry int,o the regres-

sion model for C. demersum and P. foliosus. Time and pH

were included in the equat,ion for E. canadensis (R2=0.88,

p=0.005, n=8). In M.. exalbescens, depth was entered

248

)(f,'=O.54, p=0.02, n=10), and pH was significant for p.

zosteriformis (R2=0.49, p=0.02, n=10).

All species except p. foliosus gave reqression egua-

tions for starch. Time appeared to be an important factor,being the single variable entered int.o equations fore.. demersum (¡2=0.50, p=0.01, n=LZ), M. exalbescens (R2=

O.4l , p=O.12, n=7), and p. zosteriformis 1R2=0.65, p=0.05,

n=6). fn E. canadensisr pH was accepted in the regression

model for starch (p2=0.64, p=0.11, n=5).

only P. foliosus and p. zosùeriformis had significant,regression equations for fructose. Time was entered forP. foliosus (n2=0.47, p=0.01, n=13), while depth and tightwere signifÍcant for p. zosteriformis (R2=1.0, p(0.001,

n=3).

No significant equations were found for e-. demersum

and E. canadensis with respect to glucose. The variablestime and pH rrere entered into equations for M. exalbescens

)(R¿=0.60, p=0.04, n=10) and P. zost,eriformis (R2=1.0, p=O.OZ,

n=3). rn P. fotiosus, time ras accepted into the equat.ion.)

(R'=0.43, p=0.02, n=13).

Time and light were accepted Ínto the regression

equation for sucrose in g. denersum (Rz=O.73, p=0.02, n=10)

and P. zost'erif ormis 1R2=1 .0, p(0.001 , n=3 ) . The variablepH was enùered int,o the model for M. exalbescens (n2=0.50,

p=0.02, n=10) and P. foliosus (R2=0.25, p=O,Og, n=13).

249

c. Principal conponent analysis

Principal component analysis with varimax rotationwas performed on seasonal solubre carbohydrate of q. demer-

sum, E. canadensis, M. 4lbescens, I. foliosus, and

P. zosteriformis. sampling times exctuded from the analysis

vere ApriL 27, May 30, and August, 29. Starch, fructose,glucoser âod sucrose were also analyzed for al1 of the above

species except !. zosteriformis. sampling dates excluded

from st,arch data were April 27, May 30, June 27, and August

29, while Àpri1 27, May 30, August, B, and August 29 were

omitt,ed for analysis of Èhe individual suglars.

Three components vere retained for soluble carbohydrate

content (Fig. 85) and accounted for 4I.6, 38.9, and IZ.Z %

of the variat,ion, respectively. The f irst fact,or had a

large positive loading on P. zosteriformis (.SSZ¡ and a

large negative loading on M. exalbescens (-.9¿0). The

second component had a large positive value for p. foliosus(.g+l) and a large negative value for E. canadensis (-.g10).

The third component rr¡as important wit,h respect, to q. demer-

sum (.951), white loadings on other species rìrere much smaller.

Correlation analysis of t,he 3 components wit,h dept,h,

fight, and pH (tante 39) revealed a significant, positive re-lat,ionship between Component 1 and depth (r=0.89, p 0.05)

and a significant negative relationship between component 1

and 1ight, (¡=-0.89, p 0.05).

The 3 components retained wit,h respect to starch con-

tent accounted for 49.8, 34.5, and 15.1 % of the variance,

respectively (Fig. 86). The first component had high posi-

tive loadings for C. demersun (.620) and M. e_xafbe.scen-g

(.956). The second component had a high positive value for

P. foliosus (.973) and a high negative value for e.. demersum

( -.606 ) . The importance of the third component was greatest

for M. exalbescens (.980). No significant correlations vere

found for the 3 starch components and the environmental

parameters of depth, light,, and pH (ra¡te 40).

Principal component analysis of the variable fructose

yielded 2 significant components that accounted for 51.0 and

43.2 % of the variabilit,y (fig. 87). Component I had large

positive loadings for [. e¡galÞCggCn5 (.934) and P. foliosus(.909). The second component had high positive loadings

on C. demersum (.ggZ) and E. canadensis (.918). Analysis

of the 2 components revealed no sígnificant correlation with

depth, light, and pH (ta¡te 41).

The 2 components retained for qlucose accounted for

74.8 and 2L.O % of the variability (Fig. 88). Component, I

had high positive loadings on M. exalbescens (.798), P.

foliosus (.805), and E. canadensis (.980). Component 2 had

a high positive value for q. demersum (.98i) and negative

readings for M. exalbescens (-.586) and P. foliosus (-.515).

Correlation analysis showed that the 2 components were not

significantly correlated with environmental variables (Table

42) .

The first, 2 components retained for sucrose content

accounted for 62.4 and 26.3 % of the variabilit,y (Fiq. 89).

254

251

The first component had high posiüive loadings for c. dener-

sum (.937) , E. canadensis (.851 ), and M. exalbescens (.934).

The second component appeared to have sinilar importance for

E. foliosus (.993). No significant, correlations rrere found

for the components and environment,al parameters (Tabre 43).

Table 30. Correlation of environment,alcarbohydrate, starchr âDd soluble sugarsdlagonal, p = lolrer diagonal !i[ = g-15

DATE

DEPTH

LIGHT

PH

CARBO

STARCH

FRUC

GLUC

SUC

DÀTE DEPTH LTGHT

x o.47 -0.60* 0.20

0.075 x

0.019 <0.001

o.472 0.062 0.216 x

0. 503 0.378 0.904 0.568

0.010 0 -229 0. 1 sB 0.905

0.957 0.s92 0.577 0.251

0.700 0.796 0.468 0.501

0.965 0.196 0.050 0.218

-0. 85* O.49

x -0.34

* significant, correlation

PH

parameters and toüa1 solubl_efor Ç.demersum. r = upper

CARBO STARCH

0.19

-0.250.03

-0.16X

0. 585

0.003

0.141

0.736

-0.71*

-0. 3B

o .44

-0.04

-0. 1B

x

0.590

o.527

0.858

FRUC

-0.02

-o .2r

o .22

-0.430. B6*

-o .2r

X

0.005

0.636

GLUC

0.15

-0.10

o .28

-o .26

0.53

-o .24

0. 84*

X

o .206

SUC

0.02

-0.480.66*

-o .46

-0.13

0.06

0.18

0.46

X

N)LtlN)

Table 31. Corretat,ion of environmental parameters and total soluble carbohydrate,starch and soluble sugars f or E.canadensis. i{ = 5-B

DATE

DEPTH

LIGHT

PH

CARBO

STARCH

FRUC

GLUC

SUC

DATE DEPTH

X

o.579

o.944

0.r44

o.064

0. 836

0.789

O. B5B

o.728

-o .23

X

o.o44

0.987

0.382

0 .314

0.337

o.272

o.564

LIGHT

-0.03

-o.72*X

o.944

0.758

0.303

o.774

O.B84

0.871

* siqnificant correlation

PH

-0.57

-0.01

-0.03

X

o.725

0.106

0. 571

0.48'5

0. 768

CARBO STARCH

0.68

-0.36

-0.13

0.15

X

0 .222

o .251

0.175

0.638

-0. 13

-o.52

0.58

-0. B0

-0.66

o .617

o.777

0 .492

FRUC

-0.r2

-o .43

ñ 1/1

o .26

0. 50

0.38

X

0. 004

0.974

GLUC

-0.08 -0.16

-o.48 -O.27

0.06 0.08

o.32 0.74

0.58 O.22

o.22 0.51

0.92* O.02

x -o.24

0. s97 x

SUC

f.J(¡UJ

Tabl-e 32. Correlation of environmental parametersstarch and soluble sugars for M.exalbescens. N -

DATE

DEPTH

LIGHT

PH

CARBO

STARCH

FRUC

GLUC

SUC

DATE DEPTH

o .420

0.951

o.757

0.198

o .72I

0.569

o.072

0.318

-o.29

0.041

0.531 -

0.016

0.875

0.238

0.250

0.159

LIGHT

o.02

-0.65*

0.184

o .236

0. 358

o .269

o .242

0.086

* significant correlation

PH

0.11

o .23

-o .46

X

o .407

0.490

0.483

o.2I4

0.023

CARBO STARCH

and total soluble7- 10

-o .44

n ??*

-0.41

0.30

X

o.257

o.077

0.041

0.096

o .64

-0.07

-o .4r

-o.32

-0.50

0. 694

o.294

0.837

FRUC

-o .20

o .4I

-0.39

o .25

0.58

-0. 1B

0.073

0.117

carbohydrate,

GLUC

-0.59

0.40

-0.41

o .43

0.65*

-0 .46

0.59

0.303

SUC

n ?q

o .48

-0.57

0.71*

0.55

-0.10

0. s3

0.36

X

wLN

'N

Table 33. Correlation ofstarch and soluble sucrars

DATE

DEPTH

L]GHT

PH

CARBO

STARCH

FRUC

GLUC

SUC

DATE DEPTH

o .254

0.716

0. 159

0.728

0 .392

0.010

0.015

0. 864

o .34

0.005

0.410

O. BB2

0.463

0.551

0.618

0. 607

environmental parameters and tot,al solubleforP.foliosus.N=13

LÏGHT

-0. 11

-0.73*

X

o .220

0.591

o.793

o .642

0.793

0.655


PH

-o .42

o .25

-0. 36

À

o .292

o.720

o.r23

0.140

0.079

CARBO STARCH

-0. 11

-0.05

0.16

-0.36

X

0.905

0.706

o.724

0.031

o .26

-o .22

0.08

0.11

-0.04

X

o .717

0. 996

o .222

FRUC

-0.68*

-0. 1B

o.14

o .45

o.12

-0. 11

X

..'0 . 001

o .237

carbohydrate,

AT TTAU!UU

-0.66*

-0. 15

0.08

0 .43

n 11

0.002

0.98*

X

O.I2B

SUC

-0. 05

-0. 16

n 1/1

-0.50

0.60*

-0. 36

-0. 36

-o .44

X

t\)(nLN

Table 34. Correlation of environmental parametersstarch and soluble sugars for P.zosteriformis. N

DATE

DEPTH

LIGHT

PH

CARBO

STARCH

FRUC

GLUC

SUC

DATE DEPTH

1.

0. 396

o.734

0.601

o.752

0.051

0.196

0.012

0.073

-0. 30

À

0.016

o .454

o.932

0.606

0.075

0.110

o .794

LIGHT

-o .72

-0.73*

o.945

o.342

o .434

0.863

0.678

0.593


-0. 19

-o.27

-o.02

X

o.o24

0.054

0.075

0.110

0.194

CARBO STARCH

and total soluble= 3-10

-o.12

0.03

o.34

-0.70*

-¿t

o.344

o .447

o .262

o.177

0.81*

-o .27

-0.40

0. B0*

-o .47

Å

FRUC

-0.95

-0.99

o.27

0.99

-o.761 aì^

X

0.185

o .210

carbohydrate,

GLUC

_l nn* n oo

-0.98 0.95

0.48 -0.600.98 -0.95

-0.92 0.96

-1.00 1.00

0.96 -0.91

x -0.99

0.085 x

SUC

l\)L¡

257

Table 35. Liqht (percent of surface PAR) and pHat various depths and sites in Shoal Lake duringthe 1985 growing season.

DATE

May 2May 2May 2

May 16May 16May 16May 16

May 30May 30May 30

June 13June 1 3

'June 13June 13

June 27June 27June 27

July 10-11July 10-1 1

July 10-1 1

July 10-l 1

August B

August IAugust B

August B

August B

Augtust' B

August 29August 29August 29

STATION

I

4

1

64

DEPTH ( m )

J55

J

5B

13

000

5000

LIGHT

¿a

31

7

31

2

31I

45

31

2/1-56

1

z6

i5

B

I451

0.5

¿+o

I29

2316

30.5

206

15

pH

i45

1

46

L4

8IB

1..7

77

055

U

0rì

0

001

5565

I45

1

446

7a

-

7-

000

5050

/1-45

22I1

1

3

5666

356

6

7

-a

-'l

25445

47A-43

3?J

550055

55h

B

1

3

31

33

z49501

öB-

B

7'7

7B

B

177

7J

r.2

Table 36. Correlation analysis ofenvironmental parameters. N = 3O

258

DATE

DEPTH

LIGHT

PH

DATE DEPTH

Ä

0. 548

o.753

0. 843

* :tntrificant, correlation

-0 . 11

X

<0.001

O. BB9

LIGHT

-0.06

-0.65*Y

O.9BB

PH

0 .04

0.03

0 .003

X

Table 3/;r St,epwise multiple regression equations forst.arch content of macrophytes during the 1985 season

carbo C. demersum* 15

E. canadensÍs B

M. exalbescens 10

P. foliosus* 1 3

P. zosteriformis 10

SPEC]ES N

starch C. demersum

E. canadensi s

M. exalbescensP. foliosus*P. zosteriformis

^2t(

O. BB

o .54

o .49

*no variables met the 0.15 signif icance level for entry into tfre lno6er

mg

mg

T2

5

13

6

equiv gluc/gequiv gLuc/g

total soluble carbohydrate and

0. s0

o .64o .4r

0.65

mg equiv gLuc/g

EQUATION

mg starch/g = -I2.46(time) + I40.64mg starch/g = -I43.54(pH) + 1148.06mq st,archlg = 14.05 (time ) + L2.97

10.67(time)2.81(depth)

= -38.08(pH) +

mg starch/g = 23.O7 (time) - 70.47

+ 53.11(pH) - 39s.Bs+ 44.02

330.10 tJ(¡\o

Table 38. Stepwise multiple regression equatíons for soluble sugar content of macro-phytes during the 1985 season.

fruc C. demersum* 10

E. canadensis* 7

M. exalbescens* 10

P. fol iosus 1 3

P. zosteriformis 3

C. demersum* 10

E. canadensis * 7

M. exalbescens 10

P . fol iosus 1 3

P. zosteriformis 3

C. demersum 10

E. canadensis 7

M. exalbescens 10

P . fol iosus 1 3

P. zosteriformis 3

SPEC IES

gluc

suc

o .470.99

* no variables met the 0.15 significance level for entry into the mode]

mg equiv gluc/gmg equiv gLue/g

0. 60

o .431 .00

0.78

0. 50

o .25

1 .00

EQUATION

mg

mg

mg

equiv glwc/gequiv gluc/gequiv gluc/g

-2.61 ( time )

-? I'l ¡/Áôh+h\J.¡f\vç}¡,9¡¡/

mg equiv gLuc/g = 0.39(time) + 14.62(Iiqht) - 7.75

mg egulvmg equivmg equiv

+ 25.42- 8.20(1iqht) + 2I.Bg

3.98 (pH) -0.85 ( time ) - I7 .72

-2.40(time) + 24.I'7-1.18(time) + 0.81(pH) + 9.06

gluc =

gluc =

¡'l rr nYruL

s.BB(pH) - 3B

-15.88(pH) +

-r7.43 (risht)

.12

140.10+ I.22 (time) + 14.80

NJOì

26r

Fiq. 85. Posit,ions of macrophytes with respectt,o t,he f irst 3 principal components in terms oftotal solu]¡1e carbohydrate content.1=C.demersum 2=E.canadensis 3=M.exalbescens5=_P. f ol iosus 10=P. zosteri f ormi s

262

c3 12.2%

c2 38 -9%

cr4r.6%

Table 39. Correlation of environmentalfirst 3 principal components for totalcarbohydrate content.

DEPTH

LIGHT

PH

FACT 1

FACT2

FACT3

DEPTH LIGHT

0 .229

0.191

0.045

0.951

0. 856

-0. 66

0.981

0.041

0.689

0 .455


PH

-0.70

-o.02

Ã

o .620

0.683

0.331

factors withsoluble

.c¿\ur 1

0. B9*

-0. B9*

-0. 30

0. 909

o .62r

FACT2

o.o4

-o.25

o .25

o.07

X

0.489

FACT3

-0. 11

-o .44

0. 56

0.30

-o .4r

X

t\)O'(^J

264

Fig.86. Positions of macrophytes with respectto the first 3 principal components in terms ofstarch content. 1=C.demersum 2=E.canadensis3=M. exalbescens 5=P. foliosus

265

c3 1s.1%

LlF

I

LI

-I

c1 49 .8%

Table 40. Correlation of environmentalfirst, 3 principal components for starch

DEPTH

LIGHT

PH

FACT 1

FACT2

FACT3

DEPTH LIGHT

o .268

0. 564

0.400

0. 345

0.523

-o.'73

X

o.374

0.361

0.996

o.979

PH

o .44

-0.63

X

0.815

0.760

o .499

factors withcontent.

FACT 1

-0. 60

0 .64

0.18

X

0.618

0.613

FACT2

0.66 -0.480.004 -o.02

-o.24 -0.50

-0.38 -0.39x -0.51

0.486 X

FACT3

t\)Oì

267

Fig.87. Positions of macrophytes with respectùo t,he f irst, 2 principal components in terms offruct,ose content. 1=C.demersum 2=E.canadensis3=M. exalbescens 5=P. foliosus

268

c243-2%

J

ö

7

6

5

4

3

¿

III

56789341

2

3

Á=

5

6

7

I

9l

qâ.9876

c1sr .0%

Table 4I. Correlation of environmental factors r+ithfirst 2 pr incipal components for fructose content,.

DEPTH

LIGHT

PH

FACT 1

FACT2

DEPTH LIGHT

X

0.643

o .220

0.830

0. 960

-0. 36

X

o.727

0.510

0.988

PH

-0.78

-o.27

o .682

0.761

FACT 1

0 .I7

o .49

-0.32

X

o .220

FACT2

0. 04

-0.01

-0 .24

-0.78

X

O"r(o

270

Fiq. BB. Positions of macrophytes with respectto the first 2 principal components in t,erms ofglucose content . 1=-C . demersum 2=E . canadens i s3=M. exalbescens 5=P. foliosus

lc

N "-lC)N

bs

r-{ vOl-

r--lf--c\

or@t--(oút\lco(\ -{c\¡o-)<]<u.)(oF-@or

Table 42. Correlation of environmental factors withfirst 2 principal components for glucose content.

DEPTH

LIGHT

PH

FACT 1

FACT2

DEPTH LTGHT

X

0.643

o .220

0.435

0.819

-0.36

X

o.721

0.535

0.486

PH

-o.78

-o .27

X

o .222

0.650

FACT 1

0. 56

o .46

-0.78

X

0.140

FACT2

-0.18

-0.51

0.35

-0. B6

X

N){t!

273

Fig. 89. Positions of macrophytes r¿ith respectto the first 2 principal components in terms ofsucrose content. 1=C.demersum 2=E.canadensis3=M. exalbescens 5=P. foliosus

274

oø

1

Â

?

1

1

L

4

5

6

7

.1 .2 .3 .4.5 .6 .7 .B .e O

c226 -3%

i

I8f

^l cl" I 62.4%

t

Table 43. correlation of environmental factors r¡ithfirst 2 pr incipal components for sucrose content.

DEPTH

LIGHT

PH

FACTl

FACT2

DEPTH LTGHT

1.

0.643

o .220

0.561

0.738

-0. 36

Ã

o.727

0.481

o .287

(fl

-0.78

-o .27

X

0 .946

0.668

FACT 1

-o .44

o .52

-0.05X

0.060

FACT2

o .26

-o.7r0.33

-o.94

N)\](¡

276

DTSCUSSION

The overarl range in totar soruble carbohydrate forthe shoar Lake macrophytes r¡¡as large during the 1gB5 gror,ring

season, with a seasonal mean for each species of less than10 % dry weight. Results agreed with a generalízaLion made

by Janauer and Englmaier (1986) trrat totar sugar concentra_tions rarely exceed this rimi L (ro %) in aquat,ic planrs.values compared well wit,h published data for some submerged

macrophytes including c. demersum and E. canadensis (Best

I977; Janauer I979; I9B2a; 1gB2b; Janauer & Englmaier t9B6).observations of soluble carbohydrate in E. canadensis by

Janauer (1981a) l/ere similar to the lower revel of the rangereported for t,his species in the present study. The overallseasonal mean for Ç. demersum was higher than that, found inthis species by Best and visser (tgaz). soluble carbohy-drate content in p. richardsonii was also higher t,han pre_

viously reported revers for t,his macrophyte (pip & ste¡,¡art7976). The seasonal contgnt, of soluble reserves for 6 ofthe species st,udied Lras greater than values observed forthe same species in shoal Lake during Lhe rg}4 growing sea-son (Pip & Sutherland-Guy 1987). The higher levels in t9B5

were at least partially attributable to the great,er effi_ciency of the hot alcohol extraction procedure used in thepresent study. carbohydrate content for all macrophytes ex_

ceeded levets reported for 3 other submerged species (ritus &

Àdams r979,' Best & Dassen rgBT ) , ruhile quantit,ies were towerthan those found in Ranunculus fluitans Lam. (Janauer 1981b;

271

1982b). variation in reported values may be influenced by

the degree to r+hich seasonal, vertical r âfid horizontal f 1uc_

tuation was taken into account in these st,udies. The dis-parity in content of tot,al soluble carbohydrate in reportson t.he same species may ref lect the dif ferences in met,aboric

response of a particular plant to different environments.

M. exalbescens was the only species with a sufficientnumber of samples to allor+ observations of trends in carbo_

hydrate content of organs other than shoots and leaves.Roots consist,ently contained signifícantly more solublecarbohydrate t,han shoots and reaves in this species over a

range of 3 sampling dates. This pattern \{as contrastea uy

one P. zosteriformis sample that contained significantlymore soluble carbohydrate in shoots and leaves than inroots. Titus and Adams (1979) found that total nonstruc-tural carbohydrates in Myriophyllum spicatum L. tended t,o be

higher in shoots t,han in roots during July and August of z

consecutive seasons.

Although shoot:root ratios in submerged plant,s are

usually higher than those of terrestrial herbaceous pl_ants

(ritus & Adams r97g), roots in M. exalbescens and perhaps

other aguatics may play an important role in carbohydrate

storage. small sample size made it impossible to measure

starch content of M. exalbescens roots.

Sucrose is commonly found as the predominant sugar inmost terrestrial plant,s and this appeared to be true formany of Lhe macrophyt,es in the present st,udy. sucrose

serves a major role in transport,ing glucose from source to

sink regions and is the primary substrate for the biosyn-

thesis of many plant substrates including starch (Ouffus &

Duffus I9B4). Advantages in using this disaccharide for

transport include the non-reducing nature of sucrose, its

high solubi 1i t,y (I19 g,/ 100 ml at 0 C ) , and i ts f ree energy

of hydrolysis (Akazawa & Okamoto 1980).

Sucrose was the primary sugar for most of the 1985

growing season in E_. canadensis, P_. f oliosus, p. qramineus,

B. richardsonii, !. robbinsii, âñd P. zosteriformis, and for

at least one sampling dat,e in E. exalbescens and p. prae-

longus. TotaI soluble carbohydrate ¡rras significantly (r=0.60,

p(0.05, n=13) positively correlated wit,h sucrose in p. folio-

sus. Positive correlations ì¡ere also observed for total

soluble carbohydrat,e and sucrose in E. qënadC_¡lg¿S, M. exll-

bescens, and B. zosteriformis. The sucrose content of _8.

canadensis in mid-June (72 %) was similar to 1evels reported

for t,his species and June sampling time by Janauer (1981a).

Sucrose was also the predominant sugar detect.ed by Janauer

in several submerged macrophytes including Potamogeton

pectinatus L. (I979; 1982a; 1982b). Pip and Stewart (1976)

in contrast found that fructose was the most abundant sugar

in P. pectinatus and P. richardsonii.

Glucose appeared to be an important sugar during parts

of the 1985 season in U. çj.afÞCsçens and N. flexiliÐ. Gtu-

cose was significantly (r=0.65, p<0.05, n=7) posit.ively cor-

related with tot,al soluble carbohydrate in the former sþecies.

278

279

other macrophytes in which grucose has been reported as a

primary sugar include callitriche obtusanqu.r_a Le Ga1r,

Mvriophvllum yc-r!is.i-l-lalg L. , and Etodea nuttallii (pranch. )

St,. John (Janauer I9B2b; Best & Dassen 1987).

sugars detected in e. demersum in addit,ion to fruccose,glucoser âDd sucrose were melibiose t ràffinose, and stachy_ose. A seventh component, in the soluble carbohydrate frac-tion of this species !Ías eluted between melibiose and a meli-biose/raffinose combination in paper chromatography. Thisunknown represented 10 to IB % of total soluble carbohydrateduring t,he 1985 growing season. Best and van der werf (ig86)and Best and visser ( 1gB7) det,ect,ed 2 unidentif ied components

that, also eluted between melibiose and raffinose in GLC anal-ysis of sugars in Ç. demersum. Each of these unknown ac-counted f or approximat,ely I0 % of t,otal soluble carbohydrate.The unknown detected in the present study was hypot,hesized tobe a product of t,he hydrolysis of stachyose, on t,he basis ofinformation obtained in NMR analysis.

rndividual proportions of fructose and glucose oftenexceeded sucrose levels in c. demersqm during the igB5 sea_

son. The combined proportion of raffinose, stachyose, and

melibiose (inctuciing the unknown) accounted for the majorproportion of soluble sugars for all sampling dates, rang-ing from 33 to 50 %. The proportion of these combined sugarsdid not change significantly over the growing season. Bestand van der werf (1986) and Best and visser (rg}7) also foundthat monosaccharides exceeded sucrose l_evels in c. demersum.

2BO

These workers reported that raffinose and melibiose accounted

for 33 to 34 % of toLal soluble sugars. Best and Visser

observed that the stachyose/raffinose concentrat,ion was rela-

tively constant throughout the season.

The raffinose family of oligosaccharides (including

stachyose) is widely distributed in plants (ney 1980; Lewis

1984). The primary role of this group of sugars in leaves,

vegetative organs, and seeds is to serve as storage carbohy-

drate. Stachyose is particularly imp.ortant for energy stor-

age in Hippuris vulqaris L., a macrophyte that lacks starch

entirely (Janauer & Englmaier 1986). Members of the raffi-

nose series are non-reducing like sucrose and are usually

present in species where sucrose is not the major form of

transport sugar (Giaquinta 1980). Stachyose has been iden-

tified as an important transport carbohydrate in many plants

(Dey 1980) including C. demersum (Best & Visser 1987).

Melibiose is a component of the trisaccharide raffinose

and is considered to be a rare sugar in ptants (Lewis 1984).

This sugar accounted for more than IO% of total soluble

carbohydrate in c. demersum and compared well to previously

reported tevels of B% (eest & van der Werf 1986) and 7%

/-(Best & Visser I9B7 ) in this species.

Myo-inositol has been detected in minor quantities (gen-

erally l-ess than 3% ot total sugars) in a number of aquatic

species (Janauer 1981a; 1981b; I9B2a; IgBZb; Best & van der

Werf 1986,' Janauer & Englmaier 1986; Best & Vísser 1987).

This al-cohol sugar did not react with aniline diphenylamj-ne

287

and hence was not measurable in the present study. The

aldehyde or keto group of a sugar is reduced to a hydroxylgroup in sugar alcohols, and consequent,ly many techniques

for sugar analysis do not reveal the presence of these com-

pounds (Loescher 1987).

The overall range in starch content of shoots and leaves

for t,he macrophyt,es was greater than t,he variation in solu-

ble carbohydrate during 1985. Seasonal means for each spe-

cies ranged from 37 to li8 ng/g and were higher than levels

reported for several submerged species (Best rg77; Janauer

19Bla; 1981b¡ I9B2a; l9BZb¡ Best & Dassen 1987; Best & Visser

7987 ) in similar quantification methods. Findings \{ere not

consistent with a generaLizaLion by Janauer and Engtmaier

(1986) that starch in leaves and stems of many macrophytes

is less than 7 % dry weight. Best (1977 ) found that t,he

starch content of q. demersum and E. canadensis lras just de-

tectable ( 1 %) in June-July and reached seasonal maximum

levels of only 3 to 3.5 % dry weight. fn the present study,

t,he mean starch content, accounted for approximately 6 % dry

weight in q. demef sum and 10 % dry weight in E_. canadensis.

Starch levels in C. demersum were more than twice as hiqh as

summer levels observed in this species by Best and Visser(1e87).

some seasonal differences in soluble carbohydrate con-

tent of macrophytes were observed durinq the 1985 season.

species represented by 3 or more consecutive samplingi times

showed a tendency for a seasonal maximum. These peaks

occurred at, different times of the grolring season: May 30 _

'June 13 in P. foliosus, June 13 in p. sramineus, June 27

July 10-i1 in p. zosteriformis, July 1o-11 in e.. demersum

and P. robbinsii, and August B in E. canadensis. solublereserves in M. exalbescens gave a peak early in the season

(April 27 - May 16) and a smaller peak on August, B. Totalsoluble carbohydrate had a posit,ive correration wit,h time forc. demersum and E. canadensis, while neqative relationshipsr/ere observed for M. exalbescens, p. foliosus, and p. zoster_iformis. Relationships were strongiest for M. exalbescens

and E. canadensisr compâring well wit,h respective early and

late seasonal peaks in t,hese species. Among the 5 species

analyzed in st,epwise regression, Ð. canadensis was the onlymacrophyte in r+hich time was entered into the equation forsoluble carbohydrate when considered with the factors pH,

dept,h , and 1i ght .

A number of workers have also observed a tendency forsoluble carbohydrate accumulation at certain times of the

season. Best and visser (1987) found that soluble reservesin C. demersum reached a seasonal maximum on July B (between

April 29 and July 22), comparabte to findings for this spe_

cies in t,he present study. Best (1977 ) in contrast reportedthat total carbohydrate content of e. demersum qave a season-

a1 minimum level in June of 2 conse.cutive years. Soluble

sugars accounted for Lhe major proportion of total reserves

in t,he latter study, where a minimum for E. canadensis and an

overall accumulat,ion of tot,al carbohydrate was also reported

282

283

between June and August, simitar to the late seasonal peak

observed in t,he same species in the present study. Tot,al

sugar concentration in several submerged species st,udied by

Janauer (1982a) showed a maximum in August or september.

soluble carbohydrate contenL of Elodea nut,tallii rras higherin september t,han in June (Best, & Dassen 1gB7) and shoots ofMvriophvllum spicatum tended to accumulate Lotal nonscruc-

tural carbohydrates (including starch) between June and

August (Titus & Adams 1979). pip and ster+art (r976) ob-

served that soluble carbohydrate content of potamoqeton

pectinatus and P. richardso_nj_i r^ras highest early in the grow-

ing season.

The positive correration of soluble carbohydrate r¿ith

time in E-. canadensis and q. demersum and the negat,ive cor-relation in P. foliosus presented interesting paralle1s witha study by Pip (1987). This worker found that total chtoro-phyll content increased siqnif icantry r,¡ith time in t,he f ormer

2 species and decreased in p. foliosus during the 1gB5 grow-

ing season. rncreases in pigment concentrations appeared torelate to comparatively long periods of active metabolism in

1n

canadensis and ç. demersum, while decreases in chlorophyll

P. foliosus accompanied a general seasonal loss of vital-

ity. Changes in soluble reserves in these macrophyt,es may

have resulted from increases or decreases in photosynthetic

ef f iciency as af f ect.ed by 1ight,-harvesting capacity. M.

exalbescens and P. zosteriformis also showed a general sea-

sonal decrease in soluble carbohydrate content, but these

284

species did not sholr defined chlorophyll differences during

the season (Pip 1987). Photosynthetic efficiency may have

been relat,ed to other factors in these species, such as

light quality and quantity, temperat,ure, and age of tissue.

It is also important to note that t,he carbohydrate content

of tissue is not a direct indicator of efficiency in energy

conversion, due to varying respirat.ion rates and losses of

carbon through secretion.

Starch concentrations often exceeded 1eve1s of soluble

sugars, with the overall mean starch:so1ub1e carbohydrate

ratio approaching or exceeding 2 in 6 of the 10 species

studied. The proport,ion of starch in q. demersum ranged

from 47 to 77% of total carbohydrate over the 1985 season

and compared well with the summer mean of 62% reported for

this species by BesL and Visser (1987). The only other com-

parable proportion for a submerged species was observed in

Elodea nuttallii, which had starch levels twice as high as

soluble carbohydrate during parts of the year (Best & Dassen

1987). The high proportions of starch observed in the

present study contrasted with the remaining reports of sub-

merged macrophytes that suggest soluble carbohydrate is the

predominant reserve substance (Best 1977; Janauer 1981a;

1981b; 1982a; I9B2b¡ Janauer & Englmaier 1986).

There lrere fewer siqnificant seasonal trends in starch

than Liere observed for soluble carbohydrate content during

1985. This may have been due to the generally smaller sample

size available for starch analysis. Starch was significantly

285

(¡=-Q.7I, p=0.01, n=9) negatively correlated raith time in

S. demersum and marginally significantly (r=0. B1 ¡ p=0.05,

n=3) positively correlated with time in P. zosteriformis.

Starch content was negatively correlated with time in E.

qg!è_d_ensl5, r,¿hi1e positive relationships occurred in M. exal-

bescens and P. foliosus. Time i+as entered into stepwise re-

gression equations for starch in Ç. demersum, M. g:!æEçC4-8,

and P. zosteriformis r¿hen considered with depth, pH, and

r ight .

The 5 species examined in correlation analysis showed

an overall negative relationship between the 2 forms of re-

serve carbohydrate. This relationship, along with seasonal

changes in proport,ions of tot,al nonstructural carbohydrates

suggested some degree of conversion between soluble sugars

and starch in C. demersum, P. f oliosus, P. zostl:rif ormis,

and !. robbinsii. Inverse relationships were less apparent

in U. exalbe_s*ggng and E. ganadensis.

The relative abundance of individual sugars in plant

tissue at a particular time has been used by some workers to

explain the dynamics of carbohydrate metabolism. Best and

Visser ( i 987 ) viern¡ed the relative quant,ity of non-reducing

sugars in S. demersum during summer as an indication that

assimilate transport was the predominant process in this

plant. Janauer (198lb) found low amounts of sucrose and high

1evels of monosaccharide in dormant apices of E. canadensis,

where little transport of sugar would be expected. Best and

Dassen (1987) observed that the proport.ion of sucrose in

286

leaves of Polyqonum amphibium L. Irras higher at times of high

photosynthetic activity, indÍcating export of assimilates.

High levels of reducing sug.ars, on the other hand have been

regarded as an indication of starch synthesis (Janauer 1981a).

Correlation analysis of some species produced no consis-

tent relationship between individual sugars and starch con-

tent during 1985, and none of t,hese relationships were signi-

ficant. The relative abundance of sucrose and other non-

reducing sugars in the species examined during the qrowing

season did suggest t,hat mobilization of assimilates from

source regions tras an important process, and that, photosyn-

thetíc activity was high. The complex biochemistry of carbo-

hydrates in plants and the possible influence of other fac-

tors upon sugar concentrations suggest that interpretations

of sugar leve1s may oversimplify actual processes.

Negat,ive relationships of all carbohydrate variables

r¡ith water depth were more frequent than positive relation-

ships. Correlation analysis showed that soluble carbohy-

drate, fructose, glucose, sucrose, and starch were all nega-

tively correlated with depth in Ç. demersum, E. canadensis,

and P. foliosus. Inconsistent vertical relationships with

respect to soluble carbohydrate content for these species

Ì,rere also observed in I9B4 ( Pip & Sutherland-Guy 1987 ) .

These workers however found that positive relationships be-

tween carbohydrate and depth were predominant.

The lack of substantial vertical temperature fluctua-

t,ion in Shoal Lake (Pip & Simmons 1986 ) suggested t,hat

287

temperature would not be an important factor ín determining

photosynthetic rate in the plants studied. Liqht (percent

surface PAR) was significantly (¡=-0.65, p<0.001, n=30)

negatively correlated r¡ith depth during the 1985 season.

The tendency for macrophytes to contain lower levels of car-

bohydrate at greater water depth may thus have resulted from

reduced photosynthetic rates at lower light, intensities.

PhotosynLhetic rates in some species have been shown to de-

crease with increasing dept,h (Wetzel I964). Liqht reduction

with depth was suggested to be a primary cause for t,he de-

crease in photosynthet,ic activity observed in lower plant

portions of q. demersum (Best & Visser 1987). Light was en-

tered into regression equations for fructose and sucrose in

P. zosteriformis and sucrose in 9. demersum. In principal

com,oonent analysis of 5 species, the f irst, component for

total soluble carbohydrate had a significant negative rela-

tionship wiùh 1ight, (¡=-0.89, p<0.05) and a significant posi-

tive relationship with dept.h (r=0.89, p<0.05). This com-

ponent '[,ras important wit,h ¡acnonr l-^ p ?.esteËrE!Ë_rnj_q- and

M. exalbescens.

Carbohydrate and starch content in species occurring

at the I2-L4 m site sometimes showed no marked differences

with levels in samples collected at shallower dept,hs. The

ability of these macrophytes to maintain such efficiency at

0.5 to 7 % of surface PAR was remarkable. Extensive communi-

ties of

formi s ,

tr qAqaqggq_Ls, N. flexilié, !. foljpsl€, B. zosteri-

exalbescens, and q. demersum were found at the

2BB

I2-I4 m site t,hroughout the 1984 and 1985 growing seasons by

Pip and Simmons (1986). These rrorkers concluded that a com-

bination of favorable 1ight,, temperature, and oxygen factors

allowed the macrophytes to survive aù such extraordinary

depths.

Light attenuation in Indian Bay during the 1985 season

(Appendix C ) showed that sampling stations hiere similar with

respect to water ctarity. One exception was station 3, which

had relatively poor fight penetration. In spite of general

similarities in water clarity, differences in carbohydrate

content of a species between stations at the same dept,h were

sometimes large. Such variation has also been reported by

Muztar et al. (1979), Titus and Adams (1979), and Pip and

Sutherland-Guy (1987). Horizontal differences show that

data based on restricted sampling sites may not be repre-

sentative of macrophytes in a particular 1ake.

Other factors in addition to light availabiliLy must

influence the metabolic status of aguatic macrophytes.

These f actors might include temperature/ rtrater chemistry,

competition, shading by periphyton, and stress imposed by

grazers, disease, or edaphic conditions.

Janauer found that carbohydrate content of macrophytes

may be an important indicator of the Lrophic status of the

water body in which the plants are growing. This worker

found a positive relationship between sucrose content in

plant tissue and inorganic phosphorous and nitrate concen-

traLions in lake r,rater f or Potamogeton pectinatus ( 1979)

289

and leaves of Ranunculus fluitans

of t,he latter species also t,ended

eutrophic site.

In t,he present study, pH appeared to have a relation-

ship to metabolic status of some species. significant posi-

tive correlations were found between pH and sucrose content

in M. exalbescens, and between pH and starch content in

P. zosteriformís. The latter species also g:ave a signifi-

cant negative relationship between total soluble carbohy-

drate and pH. When considered wit,h time, dept,h, âild 1ight,pH was entered int,o the regression equation for soluble

carbohydrate and starch in E. canadensis, for glucose and

sucrose in M. exalbescens, sucrose j-n P. foliosus, and solu-

ble carbohydrate and gilucose in E. zosteriformis. Thus pH

'^ras the second most signif icant factor (af ter time) in re-

lat,ionship to metabolic status. Both negative and positive

relationships I'¡ere observed, and trenC.s for the same met,abolicparameter îiere inconsistent, in different species.

The positive relationships compared r.+el1 wíth observa-

tions by Fair and Meeke (1983 ) tfrat photosynthetic act,ivity

in C. demers_um increased with increasing pH over a pH range

similar to that in Shoal Lake in 1985. The positive rela-

tionship between total soluble carbohydrate and pH in E_. cana-

dC¡SfE was interesting in view of findings by Pip (1987)

that pH was positively correlated l¡ith seasonal and loca1

chlorophyll content in this species in 1985. The tendency

for nutrient content to increase r,¡ith pH may have related to

( 1981b) . Starch levets

to be higher at a more

290

changes in availability of COZ and bicarbonate in the lake

water. The lack of consistency horsever suqgested that other

f actors were operating in add j-t,ion to pH.

In view of these findings, it is proposed that addition-

al analysis of nonstructural carbohydrates in Shoal Lake

raacrophytes tvi11 incluCe an exanination of ¡rate:: chernistry

parameters, to further investigate the possible role of

these plants as trophic indicators.

Appendix A. Reagents

i. Soluble carbohydrate determination

Anthrone: Dissolve 300 mg anthrone and 3 g

in 100 ml 75% H2SO4. Store in t,he dark andfresh every 5 days.

Calibration: O.2 mg glucose per ml water

291

¿. Starch determination

Anthrone: Dissolve 200 mg

H2SO4. Store near 0 C and

Calibration: 1 mg glucose

Perchloric acid, 52% : Add

to 100 mf r¿ater.

r. Paper chromatography

Developing solution: Dissolve 2 g diphenylamine and2 mL aniline in 200 ml acetone and add 20 mL 85%

H,PO,. Use immediately and prepare fresh as needed.54

Solvent: Combine butanol, acetic acid, and water in a

52213: 35 volume proportion.

thi-oureaprepare

anthrone in 100 ml cold 95%

prepare fresh every 2 days.

per ml water

27O mI 72% perchloric acid

Appendix B. Ilean solar energy (as PAR) incident in air and at the bottom at statj-onsof measurement on each sampling day. Values are pEs-lm-2. Each value is a3 separate measurements, each in turn integrated over a lO sec interval.have been rounded. (pip 1985.)

STATION I

Incid entI

I

Bot'tom

February 20 February 26 Þ1ay 2 I'fay 16 May 30*June 13 June 27*Ju1y1O/11 August B August 29

STATION 2

Inc ident

Bottom

I 650

l9( 3. sm)

STATÏON 3

fnci dent

Bot Lom

1575 i900

240(3m) 273(3m)

STATION 4

I nc i dent

Bo t tom

1900

47 ( 5m)

540 1600

a5(4m) 22(sn)

1-7 aL the timemean of aE least

Incident values

rB90 2075

l9( tm) 71( lm)

730

89(4m)

190 2020

I2(an) 77(4n)

lBB0 2000

146(5m) 19(Bm)

200 2080

28(lm) 487(lm)

190 2130

21(5rn) 71(5m)

1700 2030

62(3m) 131(3m)

1070 2200

)Ã( 6^\ 1 RrÁ-\

r10 1790

21(lm) 450(lm)

960 1890

37(5m) I9(6m)

245 1s00

6(6m) 58( 4rn)

22rO

584( 1m)

21 60

360( tm)

t\)LOt\)

2 130 I 840

49(6m) B(6m)

Appendix B_r continued.

STATION 5

fnc ident

Bottom

February 20 February 26 Þ1ay 2 May 16 May 3O*June 13 June 27*Julyl0/11 Augtrsr 8 August 29

STATION 6

Inc i dent

Bottom

STATION 7

Inc idenÈ

Bottom

r21 5

l9(4m)

r7B0 rB30

109(5m) 83(5m)

52s

41 (6m)

1710 1960 1280 1680

960 1850

86(5m) 7(6m)

560 1840

40(sm) 99(6m)

38(10m) 28(l0m)22(I0n)42(10m) 2(10m)

160 430

2a(5n) 83(am)

2000 20s0

s7(6m) 37(6m)

t75

rB20 1980

57(6m) 24(6n)

2230

t\)ç(,

23( 10m) I 7( 10m)

2370

Appendix B

STATION B

I nc i dent

Bottomi

continued. .

STATION 9

Inci dent

Bot t om

1 200

l7(4m)

* heavy overcasL and/or severe storm conditions

I4 r0

25(am)

N)(oè

Appendix C. Light atEenuation at stations l-7 during rlie Þlav-Aur-,us-,t , l()¡ì5scasrln. Va ltles repl t.'srìnL mean ¡rcrcenLages (rI j.rrcitl c'lrL 1i.gl,r- ( l'Âli )avajlable at the srrrface. lpin tqÂqì

STAT]ON 1

Depth(m) l4ay 2 May 16 May 30 June 13 June 2j Juty lo Augus[ g Âugusr

Âir

295

n

ns.l

a¿

J

q

100

77

66

/.4

2T

I)

100

70

5B

'7 /,

21

T4

100

59

46

2B

19

B

STATION 2

Depth(m) ùIay 2 May 30 June 27 July 10 Augusr B Âugusr 29

100

75

50

29

16

5

100

B1

to

69

32

16

6

Air

rì

nq

1

a

J

IOO

60

38

J4

15

11

4

100

7B

66

34

30

s

IO

I00

58

35

29

100

96

-7^

?ô

t00

83

47

3¿+

.lo

l5

1l

IO0

76

56

JJ

19

-

1 ()

100

q')

44

2B

11

10

32.5

100

74

/,o

29

L7

9

7

4

r00

80

59

4T

13

lt

4

3

1.0

STATION 3

Depth(m) ù1ay 2 May 16 l{ay 30 June 13 June 27 JuIy 10 Augusr B August 29

continued. .

Air

n

296

0.5

100

79

63

1.0

I00

5t

1B

STATION 4

Depth(m) l4ay 2 May 16 May 30 June 13 June 27 JuIy tI Augusr B Augusr 29

I00

79

t1 |

I4

Air

0

0.5

I

2

4

5

o

7

B

t00

BI

34

1J

100

84

72

52

2l

L0

B

100

l4

49

20

100

86

60

4l

i9

t3

7

)

4

r00

-74

qL

1q,

100

100

11TL

4l

B6

79

65

3B

11

I3

B

I

r00

B1

65

46

29

1B

t1

4

0.8

t00

-7ì

36

t1

100

66

46

3B

22

14

1J

6

2

t00

B7

6s

JJ

I4

6

4

ln

r00

7T

56

41

21+

13

3

2

100

57

50

26

t0

6

I

o.4

Appendix C

STATION 5

Depth(m) May 30 June 27

continued. .

Air

0

0.5

I

2

J

4

5

6

291

100

/o

69

.+l

35

21

i6

13

I

100

OJ

JJ

22

15

IO

7

July 10 AugusE 8 August 29

100

11

100

/ô

s9

39

¿)

T2

8

4

3

STATION 6

Depth(m) May 2 May 16 May 30 June 13 June 27 July 11 August B August 2f)

5

Âv

100

]T

</,

2T

I

3

^;-rì

,.\ <

1

a

J

4

6

B

100

87

64

5

100

75

49

47

)1

9

7

2T

10

6

100

B6

s

70

50

14

t5

9

2

'tR

I00

82

6i

47

22

II

9

0.4

r00

B2

6B

s9

47

lo

S

15

r00

59

33

31

25

l9

100

ll

53

3B

22

9

q

.,5

100

63

50

36

15

5

¿

t.2

Appendix C

STATION 7

Depth(m) May 2

continued.

Air

0

0.5

1

1

J

5

6

B

298

100

B2

78

60

23

15

i1

B

5

J

Ilay 16 May 30 June 13 June 27 Augusr. 8 Augusr 29

t00

OJ

46

JJ

T7

7

J

r00

79

68

4l

24

I1

I

6

5

4

3

2

I00

vl

82

55

40

25

16

s

9

5

4

100

57

51

27

-22

20

1B

IO

15

59

10

L2-I4

r00

6B

49

3l

i6

10

5

<5

s

s

s

2)\

100

-7 1

3B

31

20

1t

7

2

AE

$ these values are nor- gìven because they were subjecE to abnormai vari.alce

7.4 IT

2

/1

<1.3

1.0

2

<2

1.4

1'>

0.7--)

I.1

Time

February 20

Ì\fay 2

l'lay 16

I'fay 30

June 13

June 27

Jull' l0/11

August I

August 29

S1'A'TION 1 STATION 2 STATTON 3 STATTON 4 STATION 5 STATION 6 STATION 7 STÄTION B STATION 9SBSBSBã.SBSBSBSBSBSB

7.g.*rr7 .652

7.8 - 7.95 8.O6 e.O

7.s 7 .5 t.65 t.sj.35 7.t3 t.q t.u4 z.+

j.3 l.z4 t.l - 7.2

7.o t.t3 o.g z.¡5 o.ss

7.1 l.t3 t.z l.z6 l.z7.8 l.a2 s.o l.g5 e.z

B.o l.e2 l.g l:84 l.l

Additionar sites' :iiii3il 1?: il:;"rå'--rtr1¿? ur, 7.5; June 27 - s 6.es, sr.- 6.s

x site only I m deep

B.15 B.t5 t.9 B.ts7 e .',2 B.ts6 t.65 7.7510

7.5 l.o9 l.s 7.5 7.55 7.6 t .sr? t .6

'** 0.75 m below ice surface

S storm conclitions, water got insi-tle instruments

7.2 t.16 t.4 7.67 t.z t.s6 t.z 7.3r2

6.9 t.o7 t.t t.o7 t.o l.t6 t.o 7. rll 7.o 7.1

s s s s s s 6.s 6.sr2

7.3 t.z4 l.z l.z7 l.z l.z5 l.z 7.2r2

8.2 t.s7 t.a a.o8 a.t g.t7 g.o 7.3r2

t .or t .s o.g7 t .o t .+B l .g l .tB l .t. 6.912

7 ..,8o'^l .94

Superscript codes (depth below sr.rrface):

I=1m2=3n3 = 3.5 m

4=4m5 = 4.5 m

6=5m

7 = 5.5 m

B=6m9 = 7.5 m

l0 = 11 m'll - l.) -

l? - 1? 5 -

N)\o(o

Appendix E. Ranges of depthlight levels for macrophytes(Pip & Sutherland-Guy I9B7).

300

SpeciesPotamogeton gramineus L.

P. praelonsus WULFEN

P. richardsonii (BENN. )RYDB.

P. robbinsii OAKES

and minimal seasonalin the study area

Potamoseton foliosus RAF. I-74P. zosteriformis FERN.

t j=r ttr"Lj-q ,WILLD. )ROSTK. & SCHMIDT

Elodea canadensis MICHX.

Ceratophyllum demersum L.Mvriophvtlum exalbescens FERN.

ñan{- l.r

range (m)

r-2

Minimum % ofsurface light

r-4

1-6

20

2-ro

0.5

Appendix F. Biomassspecies harvested inof 1985 in Indian Bav

Speci es

301

PoÈamoqeton foliosusP. robbinsi iP. zosteriformisCeratophyl 1um demersum

Myr iophyl lum exalbescensElodea canadensis

P. praelongusNajas flexilis

of individual macrophyte-,.-J--+ Ãiññ1^^ ì - -ì ¡ Trrl r¡L{UAUr A U ùOlttvlEÞ rll rltru-u u!J

(Pip & Sutherland-Guy 1987)

Mean dry wt..)

_Lgm

49A'7

23

zz

16

9

7

3

c]

5

i9

a

01

Appendix G. Siqt ificant, interspecific differences insoluble carbohydrate during the 1985 season.1 =C . demersum 2=E . canadens i s 3=U.l?]<etb.g-gçC_!-g4=N.flexi1is 5=p.foliosus 6=p.qramineus 7=?.praelongusB=P.richardsonii 9=P.robbinsii 10=P.zosteriformis

302

SPEC I ES

ALPHA=0 .05 DF=7 MSE=1 9. 3BAPRIL 27

MEAN

73.4796.70

SPECIES N

GROUPINGSNK

ALPHA=O.05 DF=82 MSE=49.48

1

¿

35

10

53

309

l81872

MEAN

43 .4331.3063.9964 .4640.97

MÀY 2

GROUPINGTUKEY'S

53

GROUPINGSNK

SPEC Ï ES

1351 3 5 10r 210I 2 10235


1

2359

10

N

369

1B15

6T2

GROUPINGTUKEY'S

MÀY 16

MEAN

2351 3 5 10r 2 10r 2 10235

43JO747340s3

783590021840

GROUPINGSNK

3535L2I23572

10109 109 1010359

GROUPINGTUKEY'S

3535L27235T2

10109109 1010359

Appendix G | õ^^L \\ uurr u . ,,

SPEC IES


I

¿

5

303

N

^9

I2

MAY 30

MEÀN

46. 3036.7398.38

SPEC I ES

GROUPINGSNK

ALPHA=O.05 DF=65 MSE=232.O

5572

1

2

3567

10

N

1B63

24

69

JUNE 13

GROUPINGTUKEY'S

MEAN

42. r2¿ö.5ó50.r293.1380. 3692 .8269.91

55t2

GROUPINGSNK

SPECIES

567L0356'72567r 2 3 10r23L 2 3 107235

ALPHA=O.05 DF=98 MSE=1 BB.0

1

2J456

öI

i0

GROUPINGTUKEY'S

N

l056756757123T2I¿J725

I23

243

?^

615

63

6

JUNE 27

MEAN

1010

10

3936493561366593477B

o¿+

o4B7BO793167931011

GROUPINGSNK

578578B 10578r24578I241-7 9B 10r-4 6

]U10

1^

6B106B

Y

GROUPINGTUKEY'S

5 7 B 107 B 107 B 107 B 101685 7 B 10I_4 6 B

r-7 9B

7-4 6

Appendix G (Cont. )

SPEC I ES

ÀLPHÀ=0.O5 DF=L72 MSE=338. /

1

2356B

910

N

33I22451

315

933

a^^

JULY 1O-11

MEÀN

54.4957.4642. LO59.2755.708r.0253.2582.23


ÀLPHA=0.05

IB

IB

B

1

I1

SPEC I ES

1010101010235691023569

I23456B

910

N

8181583Bn.st2B1T2

ÀUGUST 8

333

243

I26666

00

MEAN

DF=90 MSE=52.06


1010

459061354564863151

30

3

I49785161B5B561016

59

59

2-4 61 3-6r241-3 52-4 6r241 3-61-3 52-4 6

SPEC I ES

a

956I59

B

910B- 10B 109B-1010B 10q

ALPHA=O.05 DF=54

1

z349

trì

236813-69724523682368r2451 3-6 I1-3 5 62368

N

AUGUST 29

t26

27

66

MEAN

42 .5724 .2641.9043 .2244 .4833.96

910B-10

Y

B- 1010B 109

MSE=113.8

GROUPINGSNK

2

1

2)22

349

GROUPINGTUKEY'S

21JY2n.s.2ll . Þ .

Àppendix H. Signifieant interspecific differencesin starch content during the 1985 season1=c.demersum 2=E.qênad-ensis 3=M.q¡glbescens4=N.flexilis 5=P.foliosus 6=P.qramineus 7=P.praelonqus8=P.richardsonii 9=P.robbinsii 10=P.zosteriformis

MAY 2

305

SPECIES N

I122336512

MEÀN GROUPING GROUPINGSNK TUKEY'S

105.14 n.s. n.s.148.34 n.s. n.s.122.65 n. s. n. s .

113.95 n. s. n. s .

SPECIES N

ALPHA=O.05 DF=40 MSE=942.517

1 18^^¿J3125993

MÀY 16

MEAN

73.2571. B970.2351.33

100 . 31

SPECIES N MEÀN GROUPING GROUPINGSNK TUKEY'S

GROUPINGSNK

n.s. n.s.n.s. n.s.n.s. n.s.n.s. n.s.n.s. n.s.

2

5

GROUPINGTUKEY'S

MAY 30

3 118.89 5q 7q-95 2

5IL

Appendix H (Cont. )

ALPHA=0.05 DF=38 MSE=344 .284-

SPECIES

1

23567

10

306

I2J

2

J

^

MEAN GROUPING GROUPINGSNK TUKEY'S

42.02 2 5 777.60 1 3 6 744.98 2571O

100.11 3 1 6 739.86 2 5 7 IO

144.29 123 s61070.28 1367

JUNE 27ALPHA=O.05

SPEC I ES

23457B

910

57.7

57lJO/IU

57I 2 3 5 6 i0

57

J9J

T2

336

MEAN

169I2B

96r45

91IB4

5B77

2776557313016BT7

GROUPINGSNK

qtY-t9)p,9 102647912358258

SPEC I ES

aL

6B

910

GROUPINGTUKEY'S

9Y

B

9B

422

¿469

27I

69

10

MEAN

i0

7 9 103585B

3B726

özI47

37ro47l

104

BO

BO

B92320B195B1

GROUPINGSNK

25811651369¿)Õt16516

GROUPINGTUKEY'S

/<lx

161513692 5 101

5156

10

l0

307

Àppendlx H (cont. )

AUGUST 8

SPECIES

I

2

4569

10

N

i559563J9

MEAN

3838

r02t20t42

3295

r27

7749959324BO4I36

GROUPÏNGSNK

4 5 104 5 10n.s.

r261264 5 10n.s.

r26

SPECI ES

ALPHA=0.05 DF=3 1

GROUPINGTUKEY'S

I

239

10

Àf

351

n

1

5n

1

AUGUST 29

510

r23

t236

MEAN

52 .8957.r784.7 7

82.7516I .44

10

.s.26i0¡ù¡26

MSE=1 858.66

GROUPINGSNK

101010107239

GROUPINGTUKEY'S

i01010n.s.723

308

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