In Light of Energy: Influences of Light Pollution on Linked Stream-Riparian Invertebrate ...

114 Pages·2012·1.24 MB·English

In Light of Energy: Influences of Light Pollution on Linked Stream-Riparian
Invertebrate Communities

THESIS

Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in
the Graduate School of The Ohio State University

By
Lars Alan Meyer
Graduate Program in Environment and Natural Resources
The Ohio State University
2012

Committee:
Professor Mažeika S.P. Sullivan, Advisor
Professor Mary M. Gardiner
Professor Paul G. Rodewald
Copyrighted by
Lars Alan Meyer
2012
Abstract

The world’s human population is expected to expand to nine billion by the year
2050, with 70% projected to be living in cities. As urban populations grow, cities are
producing an ever-increasing intensity of ecological light pollution (ELP). At the
individual and population levels, artificial night lighting has been shown to influence
predator-prey relationships, migration patterns, and reproductive success of many aquatic
and terrestrial species. With few exceptions, the effects of ELP on communities and
ecosystems remain unexplored. My research investigated the potential influences of ELP
on stream-riparian invertebrate communities and trophic dynamics, as well as the
reciprocal aquatic-terrestrial exchanges that are critical to ecosystem function. From June
2010 to June 2011, I conducted bimonthly surveys of aquatic emergent insects, terrestrial
arthropods, and riparian spiders of the family Tetragnathidae at nine Columbus, OH
stream reaches of differing ambient ELP levels (low: 0 - 0.5 lux; moderate: 0.5 - 2 lux;
high 2 - 4 lux). In August 2011, I experimentally increased light levels at the low and
moderate treatment reaches to ~12 lux. I quantified invertebrate biomass, family
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richness, density (individuals m ) of aquatic and terrestrial invertebrates, and measured
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reciprocal stream-terrestrial invertebrate fluxes. Using stable isotopes of carbon (δ C)
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and nitrogen (δ N), I estimated trophic position, variability in trophic position, food-
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chain length, and contribution of aquatic (i.e., epilithic algae) vs. terrestrial (i.e., leaf litter
detritus) carbon.

I found that light strongly influenced invertebrate family richness, biomass, and
density for discrete time periods over the course of the year. The experimental addition
of light resulted in a ~42% decrease in tetragnathid spider density, a ~54% decrease in
aquatic emergent insect biomass, a ~ 16% decrease in aquatic emergent insect family
richness, and a ~38% decrease in density of terrestrial arthropods entering stream.
Trophic position and variability in trophic position for the stream-riparian invertebrate
community, as well as, the families Tetragnathidae, Formicidae, and Chaoboridae
showed a strong positive relationship with ELP. The experimental addition of light
resulted in a ~2 trophic position increase in food-chain length and a two-fold increase in
variability in trophic position. Artificial light was also related to the contribution of
aquatic vs. terrestrial C at both the invertebrate community and family levels, such that
the contribution of aquatic C was lowest at moderate ELP and greatest at high ELP.
Collectively, these results are among the first to show the ecological consequences of
ELP at both community and ecosystem levels of biological organization.

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Acknowledgements
I would like to thank my faculty advisor, Professor Mazeika Sullivan, for his expert
guidance and invaluable support. Thanks to my committee members Professor Mary
Gardiner and Professor Paul Rodewald for valuable input during the initial and final
stages of this project. I also thank the School of Environment and Natural Resources
faculty and staff for the much needed top quality professional support generously
provided. I convey my appreciation to the research personnel in the Stream and River
Ecology Laboratory, SENR for their dedicated hard work in the field and laboratory
especially Paradzayi Tagwireyi, Brittany Gunther, Jeremy Alberts, Leslie Rieck, Adam
Kautza, and Xiaoxue Yang. I thank my two wonderful children Markus and Caroline for
their support in the field, laboratory, and most importantly at home.

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Vita

June 1983 .......................................................Hillsdale High School, Hillsdale, MI
July 1983- July 2003………………………. United States Navy, Active Duty.
July 2003…………………………………….United States Navy, Retired.
2008................................................................B.S. in Environment and Natural Resources
The Ohio State University

2008 to present ..............................................Graduate Research and Teaching Associate,
School of Environment and Natural
Resources, The Ohio State University

Fields of Study

Major Field: Environment and Natural Resources
(Fisheries and Wildlife)

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Table of Contents

Abstract……………………………………………………………………………………ii
Acknowledgements…………………………………………………………………….…iv
Vita…………………………………………………………………………………..…….v
List of Tables……………………………………………………………………………..vi
List of Figures…………………………………………………………………………....vii
Chapter 1: Background and Literature
Review………………………………….……………………………………………..…1.
Chapter 2: Bright lights, big city: influences of ecological light pollution on reciprocal
stream-riparian fluxes………………………………………………………………..….17.
Chapter 3: Consequences of artificial night lighting to stream-riparian invertebrate food
webs…………………………………………………………………………………......42.
References……………………………………………………………………….………85.
Appendix A: Location of study reaches, Columbus Metropolitan Area, OH…………..94.
Appendix B: Physical characteristics of urban stream reaches in the Columbus
Metropolitan Area…………………………………………..………………………..….95.
Appendix C: Insect families captured in emergence traps…………………………......96.
Appendix D: Terrestrial arthropod families captured in pan traps……………………..97.
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Appendix E: Summary statistics of invertebrate descriptors for urban stream study
reaches in the Columbus Metropolitan Area…………………………………………..98.
Appendix F: Synthesis of ELP effects on stream-riparian invertebrates….……..…...99.
Appendix G: Emergent and floating pan trap deployment (image)………………….100.
Appendix H: Experimental light deployment design……………….……………101-102.
Appendix I: Meteorological data for the Columbus Metropolitan Area, 2010 –
2011………………………………………………………………………………….…103.

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List of Tables

Table 1.1. Common stream-riparian invertebrate families found in small urban stream
systems in the Columbus Metropolitan Area………………………….……………….6.
Table 1.2. Terrestrial and aquatic biotic response to artificial night lighting………….13.
Table 2.1. Repeated measures analysis of variance for bimonthly aquatic-terrestrial
invertebrate responses to ecological light pollution for study reaches in Columbus
Metropolitan Area…………………………………………………………………...34-35.
Table 2.2. General linear models of bimonthly aquatic-terrestrial responses to ecological
light pollution for study reaches in the Columbus Metropolitan Area………………….36.
Table 3.1. Physical characteristics for urban stream reaches in the Columbus
Metropolitan Area. ……………………………………………………..…………….....69.
Table 3.2. Summary statistics for trophic descriptors of numerically-dominant
invertebrates at stream reaches in the Columbus Metropolitan Area. ………………….70.
Table 3.3. General linear models of aquatic-terrestrial responses to ecological light
pollution (ELP). ……………………………………………………………………..….71.
Table 3.4. Trophic responses of aquatic-terrestrial invertebrate community to
experimental light addition…………………………………………………...…………72.

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List of Figures

Figure 1.1. Representation of reciprocal food-web linkages in a stream ecosystem….…7.
Figure 2.1. Bimonthly aquatic-terrestrial invertebrate responses to ecological light
pollution..………………………………………………………………………..…...37-40.
Figure 2.2. Responses of aquatic-terrestrial invertebrates to experimental light
addition........................................................................................................................37-41.
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Figure 3.1. Dual isotope plots (δ C and δ N) for aquatic and terrestrial
invertebrates………………………………………………………………………….75-76.

Figure 3.2. Trophic position of aquatic-terrestrial invertebrate communities by ecological
light pollution (ELP) level …………..………………………………………………77-78.
Figure 3.3. Contribution of aquatic carbon to aquatic-terrestrial invertebrate communities
by ecological light pollution (ELP) level....................................................................79-80.
Figure 3.4. Variability in trophic position of aquatic-terrestrial invertebrate communities
by ecological light pollution (ELP) level…………………………………………….….81.
Figure 3.5. Food-chain length of aquatic-terrestrial invertebrate community by ecological
light pollution (ELP) level……………………………………………………...……….82.
Figure 3.6. Trophic response of aquatic-terrestrial community for experimental addition
of lights…………………….………………………………………………..…….…83-84.

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