The Effects of Water Flow, pH and Nutrition on the Growth of the Native Aquatic

171 Pages·2003·2.57 MB·English

by  Mark Norman Crossley

The Effects of Water Flow, pH and Nutrition on
the Growth of the Native Aquatic Plant,
Aponogeton elongatus
Mark Norman Crossley
B. Hort. Sc.
Massey University
A thesis submitted for the degree of Master of Philosophy at the
University of Queensland, Gatton.
School of Agronomy and Horticulture
Date : 3/11/02
STATEMENT OF ORIGINALITY
“I hereby declare that the work presented in this thesis has not been previously
submitted for a degree at any university. To the best of my knowledge and belief,
this thesis contains material that is original and has not been previously published or
written by another author except where due reference is made.”
………………………………
Mark Norman Crossley
i
ACKNOWLEDGMENTS
The author would like to thank his supervisors, Richard Williams, Bill Dennison and
Alan Wearing for their general assistance, encouragement, guidance, constructive
criticisms and editorial comment. Research grants from the Flora Foundation,
University of Queensland new staff scheme and Gatton College provided for much of
the infrastructure and some of the working expenses. Thanks to the Qld Dept of
Conservation and DPI forestry for the plant collection permits and access to the
collection site. Thanks also to Alan Lisle for his statistical help, David Pilon, who
designed and built the pH controller, provided the computer, wrote the software for
the controller and helped set up and debug the control system and Victor Robertson,
John Bertrum, Kath Raymont, and Robyn Collinge for their technical assistance.
Thanks also to Greg O’Sullivan who isolated the fungus Pythium fromA. elongatus
leaf and stem lesions and to the Marine Botany Group postgraduates for their
feedback and assistance with the fluorescence measurements. Finally, the author
would like to thank his wife for her considerable patience and encouragement, and for
minor editing of thesis.
ii
LIST OF ABBREVIATIONS AND SYMBOLS
CH COOH aceticacid
3
adapt adaptor
ADP adenosinediphosphate
ATP adenosinetriphosphate
AC alternating current
NH + ammoniumion
4
A Amp
ANOVA analysis of variance
et. al. and others (Latin: et alabi)
AE anion exchange mechanism
(cid:167) approximate
aq. aqueous
B boron
BRI bridge rectifier
BSP British Standard Pipe
Ca calcium
CaCO calciumcarbonate
3
CO carbon dioxide
2
H CO carbonic acid
2 3
CA carbonic anhydrase
C capacitor
Cu copper
CAM crassulacean acid metabolism
DH degree of hardness (German)
oC degrees centigrade or Celsius
(cid:303)13C delta 13carbon
D diode
DC or dc direct current
DIC dissolved inorganic carbon
dry wt. dry weight or biomass
iii
EC electricalconductivity
e- electron
ETR electron transport rates
(cid:1179) equilibrium
Figs. figures
eg. for example (Latin: exempi gratia)
FAA formalin/acetic acid/alcohol
C-4 four carbon eg oxaloacetic acid
g gas or gram
GMA glycol methacrylate
> greater than
GND ground
h hours
H+ hydrogenion
ICP inductivelycoupledplasma
I/O input/output board
ID internal diameter
Fe iron
K Potassium or kilo eg 1000 Ohm
LSD least significant difference
LSM least squares means
< less than
LED lightemitting diode
r linear correlation coefficient
r2 linear correlation coefficient squared
L litre
Log logarithm
LS longitudinalsection
Mg magnesium
MDH malate dehydrogenase
Mn manganese
m meter
µF microFarad
iv
µM microMolar
µmol micromoles
µScm-1 microSiemens per centimetre
mL millilitre
mg milligram
mm millimetres
nF nanoFarads
nm nanometres
NAD nicotinamide adenine dinucleotide
NADH nicotinamide adenine dinucleotide reduced
N nitrogen or Normality (chemistry: g equivalents L-1)
n number of samples
O/C opencollector
O oxygen
2
ppm parts per million (mg/Kg)
% percentage
PC personalcomputer
PEP carboxylase phosphoenolpyruvatecarboxylase
P phosphorusorprobability
PAR photosynthetically active radiation
± plus or minus
pwr. power
pH power of hydrogen
PK pyruvatekinase
QLD Queensland
RLC rapid light curves
Eh redox potential
REG regulator
R relay
R or r resistor
RuBP ribulose 1, 5-bisphosphate
s second
Na sodium
v
cm2 square centimetres
SD standarddeviation
SE standarderror
SAM submerged aquatic macrophytes
S sulphur
ie. that is (Latin: id est)
C-3 threecarbons egphosphoglyceric acid
TDS total dissolved salts
TS Transverse section
Tr treatment
USA United States of America
V or v volts
Zn Zinc
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ABSTRACT
The Australian native freshwater macrophyte, Aponogeton elongatus, is a decorative
aquarium plant but little is known about the ecophysiology of its growth and
environment. Formerly, plants were collected from the wild to supply the
pet/aquarium retail industry in Australia and overseas. Conservation measures
introduced by Australian State Governments now restrict this practice. To achieve an
understanding of how environmental factors can be manipulated for optimum growth
in cultivation, the long-term effects of stirred water, nutrition and water pH on A.
elongatus growth were examined in two studies.
The plants were grown in sand filled pots in aquaria, under fluorescent lights (PAR;
100µmol m-2s-1) in temperatures from 22-24°C. Slow release fertiliser (Osmocote
PlusR) placed in the sand substrate supplied nutrition. A four-fold increase in plant
growth in two months was found in stirred water with a pH level between 6.5 and 7.8
and fertile sediment. This macrophyte was also found to depend on its roots for
nutrient uptake and it was the combined effect of nutrient availability and stirring that
produced the strongest growth. The supply of dissolved inorganic carbon was the
main factor in the plant response to stirred water, presumably due to the reduction in
boundary layer resistance around the leaves. Dissolved free CO was more readily
2
assimilated than bicarbonate based on the strong growth response in water of pH 6.5
to 7.8 and strong correlation between the concentration of dissolved free CO and
2
plant growth.
It is apparent that the manipulation of nutrient level, dissolved free CO and pH
2
greatly influenced the growth of A elongatus in stirred water. These findings would
benefit the commercial cultivation of this plant and give some insight as to the extent
ofA. elongatus adaptation to an aquatic environment.
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PUBLICATIONS
Crossley, M. N. and R. R. Williams. (2001). Cultivation of the freshwater aquatic
plantAponogeton elongatus. (Poster and abstract) 20th International Eucarpia
Symposium, Section Ornamentals, Belgium, July 2001.
Crossley M. N., W C. Dennison, R. R. Williams and A. H. Wearing. (2002). The
interaction of water flow and nutrients on aquatic plant growth. Hydrobiologia
(Accepted).
viii
TABLE OF CONTENTS
Page
STATEMENT OF ORIGINALITY ........................................................................i
ACKNOWLEDGMENTS .......................................................................................ii
LIST OF ABBREVIATIONS AND SYMBOLS ..................................................iii
ABSTRACT ...........................................................................................................vii
PUBLICATIONS ................................................................................................viii
TABLE OF CONTENTS .....................................................................................ix
LIST OF APPENDICES .....................................................................................xiii
LIST OF FIGURES .............................................................................................xiv
LIST OF TABLES ............................................................................................xviii
LIST OF PLATES ...............................................................................................xix
CHAPTER 1 GENERAL INTRODUCTION .............................................1
1.1 Background to Research ...............................................................................1
1.2 Significance of this Thesis ............................................................................7
1.3 General Objectives and Thesis Structure ......................................................8
CHAPTER 2 LITERATURE REVIEW ......................................................9
2.1 Introduction ...................................................................................................9
2.2 Aquatic Sediment ........................................................................................10
2.3 The Water Environment above the Sediment .............................................11
2.3.1 Light ..............................................................................................11
2.3.2 Irradiance (Intensity) ....................................................................11
2.3.3 Light Quality (Spectral Distribution) ...........................................11
2.3.4 Temperature .................................................................................12
2.4 Chemical Properties of Water .....................................................................13
2.4.1 pH .................................................................................................13
2.4.2 Alkalinity ......................................................................................14
2.4.3 Water Hardness ............................................................................14
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