Impacts of climate change, human land use, and mercury contamination on Southern Appalachian ...

355 Pages·2016·2.68 MB·English

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Doctoral Dissertations Graduate School
8-2014
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Michael Kevin Hamed
University of Tennessee - Knoxville, [email protected]
Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss
Part of the Terrestrial and Aquatic Ecology Commons
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Hamed, Michael Kevin, "Impacts of climate change, human land use, and mercury contamination on
Southern Appalachian Plethodontid salamanders. " PhD diss., University of Tennessee, 2014.
https://trace.tennessee.edu/utk_graddiss/2825
This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee
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[email protected].
To the Graduate Council:
I am submitting herewith a dissertation written by Michael Kevin Hamed entitled "Impacts of
climate change, human land use, and mercury contamination on Southern Appalachian
Plethodontid salamanders." I have examined the final electronic copy of this dissertation for
form and content and recommend that it be accepted in partial fulfillment of the requirements
for the degree of Doctor of Philosophy, with a major in Natural Resources.
Matthew J. Gray, Major Professor
We have read this dissertation and recommend its acceptance:
Dave Buehler, Benjamin M. Fitzpatrick, John Drake
Accepted for the Council:
Carolyn R. Hodges
Vice Provost and Dean of the Graduate School
(Original signatures are on file with official student records.)
Impacts of climate change, human land use, and mercury contamination on
Southern Appalachian Plethodontid salamanders

A Dissertation Presented for the
Doctor of Philosophy
Degree
The University of Tennessee, Knoxville

Michael Kevin Hamed
August 2014
ACKNOWLEDGEMENTS

I would like to thank many people and institutions for their invaluable assistance,
support, guidance, and encouragement. First, I would like to thank the chair of my dissertation
committee, Dr. Matthew Gray, for his patience, guidance, and support during my doctoral
journey. I greatly appreciate your willingness to attempt this undertaking from a non-traditional
approach, which made the process even more difficult. Your inbox will feel lonely without my
3:00 AM emails. I would also like to thank the other members of my dissertation committee, Dr.
David Buehler, Dr. Benjamin Fitzpatrick, and Dr. John Drake for the guidance and direction you
provided. I must thank my two “unofficial” committee members, Dr. James and Della Organ,
who provided an immensely value contribution to this project. I am more than honored that you
entrusted your life’s work to me and I only hope you are proud of the results. Your friendship
not only to me, but my family was amazing. I had hoped we all could sit on the cabin’s porch
and watch red squirrels at your feeders while talking about the completed project. Della, you are
missed.
As an educator I would be remised to not thank the many amazing teachers and
professors that helped guide me to pursuing a career in biological sciences. Malcolm Sprinkle,
Harriet Locke, Randy Lacy, Dr. Frank Bulow, and Dr. Michael “Mick” Harvey, sharing your
passion for nature and learning was more important to me than any knowledge I gained; thank
you! As a student and teacher, I incorporate much of what you taught me into my classroom and
my life.
Completion of this degree and many other accomplishments in the past 20 years would
not have been possible without the help of many true friends who provided support, assistance,
and guidance including: Phil Gentry, Joel Keebler, Wallace Coffey, Jane Perry, Jason Hoverman,
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Bill Sutton, Jason Matson, and Dexton Eller. My many colleagues also provided tremendous
support including: Joel Rudy, Mary Snead, Sandy Davis, and Reva Russell. I owe a debt of
gratitude to Josh Rudd for covering my classes during my one-year absence from Virginia
Highlands Community College (VHCC). I am also very appreciative for the support and
motivation of the administrators from VHCC for providing many resources to help me obtain
this degree including: David Wilkin, Robert May, and Susan Fleming. Without The Virginia
Community College System’s (VCCS) Chancellor’s Faculty Fellowship, I would not have been
able to attend the University of Tennessee and I am very grateful for the support.
I wanted to thank the institutions and organizations that provided financial support for
this project: the Virginia Department of Game and Inlands Fisheries, U.S. Fish and Wildlife
Service, Tennessee Wildlife Resource Agency, VA Tech Prep Fund, VHCC professional growth
and development funds, VCCS Paul Lee professional development grant, and the University of
Tennessee College of Agricultural Sciences and Natural Resources Hazelwood scholarship.
Lastly, I must thank my family for without their encouragement and support I could not
have completed such an enduring task. My parents, Mickey and Doris Hamed, tolerated a house
full of every creature known throughout my childhood and I greatly appreciate their patience.
They also instilled in me the only trait that allowed me to survive this process, being a hard
worker. My sister, Alia, has always been my greatest supporter and I thank her for always being
there for me. I know much of my passion for nature was created during my childhood as I would
spend afternoons with my grandmother, Vesta Wilson, in her gardens as well as weekly walks
down to the “lower 40” with my uncle, Ray Wilson; both were great influences and I appreciate
the time they spent with me. Misty and I could not have survived this journey without much
help and I am especially indebted to the time Sue King spent helping us. I have to thank my wife
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of 18-years, Misty, for her support, tolerance, and patience through this process. I would not
have been able to complete this degree without your loving encouragement. Lastly, my greatest
accomplishment, not only during the six years of my dissertation but my life, was the arrival of
my daughter, Maddie Grace. She changed my world and I cannot wait for the adventures we
will now have time to undertake.

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ABSTRACT

The Southern Appalachian Mountains are home to the greatest diversity of Plethodontid
Salamanders in the world. The future for these salamanders is uncertain as globally amphibians
have been experiencing significant population declines. We investigated the impact of habitat
loss, chemical contaminants, and climate change on Plethodontid salamanders in northeastern
Tennessee and southwestern Virginia. Four-toed salamanders (Hemidactylium scutatum) were
negatively impacted by powerline right-of-way (ROW) mowing. Embryonic and larval survival
significantly decreased in ROW after mowing and required up to 3 years of vegetation regrowth
to reach post mowing survival. We also investigated mercury contamination in black-bellied
salamanders (Desmognathus quadramaculatus) from Whitetop Mountain, Virginia. We found
these salamanders to be contaminated with mercury levels equivalent to salamanders from point
source pollution streams. Additionally, salamander from streams facing the prevailing wind
direction had significantly greater levels of mercury contamination. To help land managers in
planning long range habitat goals for the Mount Rogers National Recreation Area, we also
developed salamander occupancy models based on parameters describing forest structure and
composition. Elevation or other abiotic factors had a greater association to occupancy than many
forest parameters. Lastly, to determine the influence of climate change on Mount Rogers Nation
Recreation Area (MRNA) salamander distributions, we compared current distributions with
those from the 1950s and 1990s and examined regional temperature changes since 1948.
Plethodon welleri, a high elevation endemic, moved down slope since both the 1950s and 1990s.
Plethodon yonahlossee expanded its range both up and down slope, but P. cylindraceus
experienced range constrictions since the 1950s. No significant differences were observed for
regional temperatures since 1948. We also modeled future salamander occupancy based on
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current mean temperature preferences. Using the Canadian Centre for Climate Modeling and
Analysis Coupled Global Climate Model (CGCM) and the Hadley Centre for Climate
Predication and Research (HAD) global circulation models with 2 different CO [carbon dioxide]
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emission projections, we projected the extirpation of P. welleri, D. organi, and Eurycea wilderae
from Whitetop Mountain by 2070. Our results provide land managers with data necessary to
better prepare for the challenges to maintain Plethodontid salamander populations.

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Table of Contents
INTRODUCTION .......................................................................................................................... 1
LITERATURE CITED ............................................................................................................... 6
CHAPTER 1 : IMPACT OF POWERLINE RIGHT-OF WAY MOVING ON FOUR-TOED
SALAMANDER NESTING AND LARVAL SURVIVAL ........................................................ 12
ABSTRACT .............................................................................................................................. 13
INTRODUCTION ..................................................................................................................... 14
METHODS................................................................................................................................ 19
RESULTS.................................................................................................................................. 27
DISCUSSION ........................................................................................................................... 35
CONCLUSIONS ....................................................................................................................... 45
LITERATURE CITED ............................................................................................................. 48
APPENDIX ............................................................................................................................... 57
CHAPTER 2 : TEMPORIAL AND SPATIAL CHANGES OF MERCURY
CONTAMINATION OF BLACK-BELLIED SALAMANDERS FROM WHITETOP
MOUNTAIN, VIRGINIA............................................................................................................. 77
ABSTRACT .............................................................................................................................. 78
INTRODUCTION ..................................................................................................................... 79
METHODS................................................................................................................................ 83
RESULTS.................................................................................................................................. 87
DISCUSSION ........................................................................................................................... 89
CONCLUSIONS ....................................................................................................................... 96
LITERATURE CITED ............................................................................................................. 98
APPENDIX ............................................................................................................................. 107
CHAPTER 3 : CHANGES IN SALAMANDER DISTRIBUTIONS ALONG AN
ELEVATIONAL GRADIENT IN THE MOUNT ROGERS NATIONAL RECREATION AREA
..................................................................................................................................................... 113
ABSTRACT ............................................................................................................................ 114
INTRODUCTION ................................................................................................................... 115
METHODS.............................................................................................................................. 121
RESULTS................................................................................................................................ 127
DISCUSSION ......................................................................................................................... 131
CONCLUSIONS ..................................................................................................................... 139
LITERATURE CITED ........................................................................................................... 141
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APPENDIX ............................................................................................................................. 151
CHAPTER 4 : VEGATATION AND BIOTIC HABITAT CHARACTERISTICS INFLUENCE
PLETHODONTID SALAMANDER OCCUPANCY WITHIIN THE MOUNT ROGERS
NATIONAL RECREATION AREA .......................................................................................... 186
ABSTRACT ............................................................................................................................ 187
INTRODUCTION ................................................................................................................... 188
METHODS.............................................................................................................................. 192
RESULTS................................................................................................................................ 199
DISCUSSION ......................................................................................................................... 204
CONCLUSIONS ..................................................................................................................... 213
LITERATURE CITED ........................................................................................................... 215
APPENDIX ............................................................................................................................. 227
CHAPTER 5 : FUTURE CHANGES IN SALAMANDER DISTRIBUTIONS ALONG AN
ELEVATION GRADIENT ON WHITETOP MOUNTAIN, VIRGINIA ................................. 254
ABSTRACT ............................................................................................................................ 255
INTRODUCTION ................................................................................................................... 256
METHODS.............................................................................................................................. 261
RESULTS................................................................................................................................ 267
DISCUSSION ......................................................................................................................... 273
CONCLUSIONS ..................................................................................................................... 282
LITERATURE CITED ........................................................................................................... 284
APPENDIX ............................................................................................................................. 294
CONCLUSIONS......................................................................................................................... 332
VITA ........................................................................................................................................... 335

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