influence of algal production on ecosystem metabolism, microbial activity and nutrient dynamics in

164 Pages·2014·1.84 MB·English

INFLUENCE OF ALGAL PRODUCTION ON ECOSYSTEM METABOLISM, MICROBIAL
ACTIVITY AND NUTRIENT DYNAMICS IN A CENTRAL INDIANA STREAM

A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE
MASTER OF SCIENCE

BY
ANDREA S. FITZGIBBON
ADVISORS: DR. MELODY J. BERNOT & DR. KEVIN H. WYATT

BALL STATE UNIVERSITY
MUNCIE, INDIANA
JULY 2014
INFLUENCE OF ALGAL PRODUCTION ON ECOSYSTEM METABOLISM, MICROBIAL
ACTIVITY AND NUTRIENT DYNAMICS IN A CENTRAL INDIANA STREAM
A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE
MASTER OF SCIENCE
BY
ANDREA S. FITZGIBBON
ADVISORS: DR. MELODY J. BERNOT & DR. KEVIN H. WYATT

Committee Approval:

___________________________________________________________ ____________
Committee Chairperson Date

___________________________________________________________ ____________
Committee Member Date

___________________________________________________________ ____________
Committee Member Date

Departmental Approval:

___________________________________________________________ ____________
Departmental Chairperson Date

___________________________________________________________ ____________
Dean of Graduate School Date

BALL STATE UNIVERSITY
MUNCIE, INDIANA
JULY 2014
TABLE OF CONTENTS

TABLE OF CONTENTS…………………………………………………………………..…….iii
LIST OF FIGURES CHAPTER 1………………………………………………………...….…..iv
LIST OF TABLES CHAPTER 1………………………………………………………...….…...vi
LIST OF FIGURES CHAPTER 2……………………………………………………………….vii
LIST OF TABLES CHAPTER 2………………………………………………………………...ix
ABSTRACT……………………………………………………………………………………….1
ACKNOWLEGEMENTS…………………………………………………………………………3

CHAPTER 1: Comparison of algal and ecosystem metabolism and nutrient dynamics in a
central Indiana stream

ABSTRACT………………………………………………………………………………….……4
INTRODUCTION………………………………………………………………………….……..6
METHODS……………………………………………………………………………….……….8
RESULTS…………………………………………………………………………….………….14
DISCUSSION…………………………………………………………………….……………...21
CONCLUSIONS………………………………………………………………….…………......26
REFERENCES…………………………………………………………………….………….....27
FIGURES AND TABLES…………………………………………………………….………....32

CHAPTER 2: Influence of algal exudates on microbial activity and ecosystem dynamics
ABSTRACT………………………………………………………………………………….…..44
INTRODUCTION………………………………………………………………………….……46
METHODS……………………………………………………………………………….……...48
RESULTS…………………………………………………………………………….………….53
DISCUSSION…………………………………………………………………….……….……..56
CONCLUSIONS………………………………………………………………….…………......59
REFERENCES…………………………………………………………………….………….....61
FIGURES AND TABLES…………………………………………………………….………....66
APPENDIXES…………………………………………………………………………………...75

iii
LIST OF FIGURES

Figure Page

CHAPTER 1: Comparison of algal and ecosystem metabolism and nutrient dynamics in
a central Indiana stream

1. Conceptual model of hypothesized algal mediated diurnal patterns of nutrients, (top
panels) dissolved organic carbon (DOC), dissolve inorganic nitrogen (DIN);
physiochemistry, (middle panels) dissolved oxygen (O ) and pH; and metabolism,
2
(bottom panels) primary production, respiration and decomposition. ……………….….32

2. Conceptual model of hypothesized seasonal water column and algae patterns of dissolved
oxygen (top panel); nutrients (middle panel); and metabolism, (bottom panels) primary
production and respiration. ……………………………………………………………..33

3. Water column and algae diurnal variation in dissolved oxygen (DO, mg O /L)
2
concentration and pH over time in July and December 2013. ………………………….34

4. Mean seasonal water column and algae dissolved oxygen concentrations. (n= 9 days per
season; Winter = Dec - Feb, Spring = Mar - May, Summer = Jun - Aug, Fall = Sep -
Nov). Error bars indicate SD. Dashed line indicates a 1:1 relationship. ………………..37

5. Mean seasonal water column and algae pH. (n= 9 days per season; Winter = Dec - Feb,
Spring = Mar - May, Summer = Jun - Aug, Fall = Sep - Nov). Error bars indicate SD.
Dashed line indicates a 1:1 relationship. …………………………………………...…...38

6. Mean seasonal water column and algae total organic carbon concentrations. (n = 9 days
per season; Winter = Dec - Feb, Spring = Mar - May, Summer = Jun - Aug, Fall = Sep -
Nov). Error bars indicate SD. Dashed line indicates a 1:1 relationship. …………….…39

7. Mean seasonal water column and algae nitrate concentrations. (n= 9 days per season;
Winter = Dec - Feb, Spring = Mar - May, Summer = Jun - Aug, Fall = Sep - Nov). Error
bars indicate SD. Dashed line indicates a 1:1 relationship. ……………………………40

8. Mean seasonal water column and algae phosphate concentrations. (n= 9 days per season;
Winter = Dec - Feb, Spring = Mar - May, Summer = Jun - Aug, Fall = Sep - Nov). Error
bars indicate SD. Dashed line indicates a 1:1 relationship. ……………………………41

iv
9. Mean daily rates of (A) GPP, (B) ER and (C) NEP measured in White River, Yorktown,
Indiana from January through December 2013 (n = 2-3 days per month). Error bars
indicate SD. Shaded area (A) indicated mean dry algal biomass (n = 12). ……………42

v
LIST OF TABLES

Table Page

CHAPTER 1: Comparison of algal and ecosystem metabolism and nutrient dynamics in
a central Indiana stream

1. Physiochemical characteristics of the water column (Water) and algae in the White River,
Yorktown, Indiana from January through December 2013. Dissolved oxygen (DO), pH,
temperature and conductivity were measured continuously at 10 minute intervals over
approximately 72 hours (n = 125-432). Width (n = 1), flow and depth (n = 5) were
measured during the sampling event. Discharge (n = 1) was calculated from width, flow
and depth. Parentheses indicate standard error. …………………………………………35

2. Cumulative mean water column (Water) and algae, total organic carbon (TOC), nitrate
(NO ), phosphate (PO ) and ammonium (NH ) concentrations. Phosphate concentrations
3 4 4
were the below detection limit (0.01 mg/L) September through December. Standard error
in parentheses, N= 48-144. ……………………………………………………………...36

3. Multiple regression model covariates for water and algal gross primary production (GPP)
and ecosystem respiration (ER). ……………………………………………....….……..43
vi
.
LIST OF FIGURES

Figure Page

CHAPTER 2: Influence of algal exudates and benthic substrata on microbial activity

1. Mean dissolved oxygen across mesocosm treatments (algae, exudate and control) over
three sampling events (n = 126 for algae treatment, n = 63 for exudate and control
treatments). Error bars indicate SE. Note y-axis begins at 7.00 mg O / L. Dissolved
2
oxygen differs by treatment (p = 0.027) but not by substrate (p= 0.241) with no
interaction between main effects (p = 0.723). Pairwise differences indicated by letters
above bars. ………………………………………………………………………………66

2. Mean pH of mesocosm (A) treatment (algae, exudate and control) and (B) substrate
(sediment, leaves, sponge and glass) over three sampling events (n = 126 for algae
treatment, n = 63 for exudate and control treatments, n = 60 for each substrate). Error
bars indicate SE. Note y-axis begins at 8.00. pH differs by treatment and substrate (p <
0.001) with no interaction between main effects (p = 0.397). Pairwise differences
indicated by letters above bars. ………………………………………………………….68

3. Mean total organic carbon (TOC) of mesocosm (A) treatment (algae, exudate and
control) and (B) substrate (sediment, leaves, sponge and glass) over two sampling events
(n = 32 for algae treatment, n = 16 for exudate and control treatments, n = 16 for each
substrate). Error bars indicate SE. TOC differs by treatment (p < 0.0001) and substrate (p
< 0.0001) with an interaction between main effects (p = 0.0073). Pairwise differences
indicated by letters above bars. ……………………………………………………….…69

4. Mean nitrate (NO ) concentration by mesocosm (A) treatment (algae, exudate and
3
control) and (B) substrate (sediment, leaves, sponge and glass) over two sampling events
(n = 64 for algae treatment, n = 32 for exudate and control treatments, n = 32 for each
substrate). Error bars indicate SE. NO differs by treatment (p = 0.0002) and substrate (p
3
< 0.0001) with an interaction between main effects (p = 0.0003). Pairwise differences
indicated by letters above bars. …………………………………………………………70

5. Mean phosphate (PO ) concentration by mesocosm (A) treatment (algae, exudate and
4
control) and (B) substrate (sediment, leaves, sponge and glass) over two sampling events
(n = 64 for algae treatment, n = 32 for exudate and control treatments, n = 32 for each
substrate). Error bars indicate SE. PO differs by treatment (p = 0.0003) and substrate (p
4
vii
= 0.0003) with no interaction between main effects (p < 0.0001). Pairwise differences
indicated by letters above bars. …………………………………………………………71
6. Nutrient ratios of total organic carbon (TOC) to nitrate (NO ) and phosphate (PO )
3 4
among treatments (algae, exudate and control). Error bars indicate SE. TOC: NO did not
3
differ by treatment (p = 0.263) nor did TOC: PO (p = 0.126). Dashed lines indicate
4
differences in nutrient availability; arrows indicate high or low amounts of nutrient
available. ………………………………………………………………………………...72

7. Mean respiration by mesocosm substrate type (sediment, leaves, sponge and glass; n =
20). Error bars indicate SE. Respiration differs by substrate (p < 0.001) but not by
treatment (p = 0.997) with no interaction between main effects (p = 0.803). Pairwise
differences indicated by letter above bars. ……………………………………………....73

8. Relationship between total organic carbon (TOC) concentration and microbial respiration
by treatment (algae, exudate and control) (p < 0.01). ………………………………..….74
viii
LIST OF TABLES

Table Page

CHAPTER 2: Influence of algal exudates and benthic substrata on microbial activity

1. Mean mesocosm temperature (°C) across algal and substrate treatments over three
sampling events (n = 126 for algae treatment, n = 63 for exudate and control treatments
and n = 60 for substrate treatments). Numbers in parentheses are SE. Temperature differs
by treatment (p = 0.010) but not by substrate (p = 0.573) with no interaction between
main effects (p = 0.371). Pairwise difference denoted by letters. ………………………67

ix
ABSTRACT

THESIS: Influence of algal production on ecosystem metabolism, microbial activity and nutrient
dynamics in a central Indiana stream

STUDENT: Andrea S. Fitzgibbon
DEGREE: Masters of Science
COLLEGE: Sciences and Humanities
DATE: July 2014
PAGES: 155
One primary function in most ecosystems is photosynthesis which provides energy for
consumers. In mid-order streams, benthic algae are primary producers fulfilling this role and
their influence on stream biogeochemistry changes with the diurnal patterns of production.
During the day, photosynthesis increases stream oxygen concentrations facilitating shifts in pH
and nutrient concentrations. However, little is known about diurnal patterns of nutrient
concentrations. Algal production regulates nutrient cycling through assimilation of inorganic
nutrients and release of nitrogen and carbon exudates. Though nutrient assimilation by algae in
streams is well understood, understanding of algal nutrient release is limited. Nutrient release by
algae is a significant gap in our knowledge of ecosystem dynamics, especially in nutrient
saturated streams. To understand algal dynamics in a nutrient saturated stream, algal production
in a mid-order stream was measured via monthly sampling for one year using microelectrodes to
quantify algal biofilm chemical gradients of dissolved oxygen and pH. Ecosystem energetics as
gross primary production (GPP) and ecosystem respiration (ER) were also calculated. Nutrients
were analyzed from water column and algal pore water samples. Dissolved oxygen
concentrations and pH between the algae and water column followed similar diurnal curves
although the amplitude of these changes varied seasonally. Nutrient and total organic carbon
1