Updates Mar. 27, 2015, Brown

113 Pages·2014·2.35 MB·English

FERAL HOG (SUS SCROFA) DISTURBANCE IN SEEPAGE SLOPE WETLANDS

By

MEGAN E. BROWN

A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2014
© 2014 Megan E. Brown
To my Dad
ACKNOWLEDGMENTS
First, I would like to thank my parents, Larry Brown and Patricia Maddox, who early on
fostered my interest in the natural world and have always encouraged me to pursue my
education. I owe much of my accomplishments to their love and support.
I would like to express my sincere gratitude towards those who helped me throughout my
doctoral experience. Mark Brown gave me the opportunity to be a part of the Adaptive
Management of Water, Wetlands, and Watershed IGERT group. My advisor, Debbie Miller, has
been great mentor and friend over the past six years. My growth as a scientist has benefited from
her experience and guidance. The other members of my committee, Carrie Reinhardt Adams,
Doria Gordon, Kevin Heirs, and Wiley Kitchens have been instrumental in providing wisdom,
inspiration, and encouragement along the way. A big thank you to Tyler Barry, Sean Claypool,
Gina Duke, Hanna Hunsberger, and Allix North for spending many long, hot, humid days in the
field, trudging through snake-infested woods and wetlands, lugging a meter square that never
stayed together, and collecting hundreds of plant specimens....all in the name of data collection. I
also give much thanks to Brett Williams with Jackson Guard at Eglin AFB and John Allen with
the USDA APHIS Wildlife Services for their support of this project. I started this doctoral
journey with seven other amazing women and I am thankful for having had the opportunity to
create such wonderful friendships.
Finally, I am grateful for the tireless support of my husband, Joshua Hornbarger, who
uprooted his life to move with me to Gator Country. I also am eternally grateful for my daughter,
Odelia (3), who provides me with more joy than I ever knew possible. I hope to instill in her an
admiration of the natural world so that she too can know and experience its beauty.
This project was funded in part by a NSF IGERT fellowship, a USDA NIFA pre-doctoral
fellowship, a McKnight Dissertation Fellowship, a Society of Wetland Scientists Student Grant,
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the Doris Lowe and Earl and Verna Lowe Scholarship (UF), and the William C. and Bertha M.
Cornett Fellowship (UF).

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TABLE OF CONTENTS

page
ACKNOWLEDGMENTS ...............................................................................................................4
LIST OF TABLES ...........................................................................................................................8
LIST OF FIGURES .........................................................................................................................9
ABSTRACT ...................................................................................................................................12
CHAPTER
1 INTRODUCTION ..................................................................................................................14
Background .............................................................................................................................14
Research Goals .......................................................................................................................15
2 INDIRECT EFFECTS OF FERAL HOG DISTURBANCE ON FIRE SPREAD .................16
Background .............................................................................................................................16
Methods ..................................................................................................................................18
Study Area .......................................................................................................................18
Data Collection ................................................................................................................20
Data Analyses ..................................................................................................................20
Results.....................................................................................................................................21
Discussion ...............................................................................................................................22
Summary .................................................................................................................................23
3 LONG-TERM MONITORING OF FERAL HOG DISTURBANCE IN SEEPAGE
SLOPES ..................................................................................................................................26
Background .............................................................................................................................26
Methods ..................................................................................................................................27
Study Area .......................................................................................................................27
Data Collection ................................................................................................................29
Data Analyses ..................................................................................................................31
Results.....................................................................................................................................32
Discussion ...............................................................................................................................35
Summary .................................................................................................................................41
4 EFFECTS OF INTENSITY OF FERAL HOG DISUTRBANCE ON VEGETATION
DYNAMICS ...........................................................................................................................49
Background .............................................................................................................................49
Methods ..................................................................................................................................51
Study Area .......................................................................................................................51
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Data Collection ................................................................................................................52
Data Analyses ..................................................................................................................54
Results.....................................................................................................................................55
Foliar Cover .....................................................................................................................55
Richness ...........................................................................................................................57
Camera Detection of Hog Activity ..................................................................................57
Vegetation Composition ..................................................................................................57
Discussion ...............................................................................................................................58
Summary .................................................................................................................................63
5 EFFECTS OF EXPERIMENTAL SOIL DISTURBANCE ON VEGETATION
DYNAMICS ...........................................................................................................................72
Background .............................................................................................................................72
Methods ..................................................................................................................................74
Study Area .......................................................................................................................74
Data Collection ................................................................................................................75
Data Analyses ..................................................................................................................76
Results.....................................................................................................................................77
Foliar Cover .....................................................................................................................77
Camera Detected Hog Frequency ....................................................................................80
Richness ...........................................................................................................................80
Vegetation Composition ..................................................................................................81
Discussion ...............................................................................................................................82
Summary .................................................................................................................................85
6 CONCLUSIONS ....................................................................................................................98
LIST OF REFERENCES ...............................................................................................................99
BIOGRAPHICAL SKETCH .......................................................................................................113

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LIST OF TABLES
Table page

3-1 Repeated measures ANOVA results for the percentage of hog disturbed plots over
time by zone on Eglin AFB from 2002 to 2012.................................................................43
3-2 Repeated measures ANOVA results for the percentage of hog disturbed plots over
time by hunting access on Eglin AFB from 2002 to 2012. ................................................43
3-3 The number of hogs removed from Eglin AFB from October 1 of the previous year
to September 30 of that calendar year. The percentage of hog disturbed plots and
rainfall totals are also indicated. ........................................................................................43
3-4 Repeated measures ANOVA results for the cover of total vegetation, functional
groups, and A. stricta by zone and access on Eglin AFB in 2002, 2010, and 2012. .........44
4-1 ANOVA results for the foliar cover of total vegetation, functional groups, and A.
stricta and species richness by disturbance intensity and exclosure on Eglin AFB. .........64
5-1 Repeated measures ANOVA results for the foliar cover of total vegetation,
functional groups, A. stricta, Dichanthelium spp., Sarracenia spp., and species
richness by disturbance frequency on Eglin AFB..............................................................86
5-2 Repeated measures ANOVA results for the foliar cover of total vegetation,
functional groups, A. stricta, Dichanthelium spp., and Sarracenia spp., and species
richness by disturbance frequency on Eglin AFB with controls........................................87
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LIST OF FIGURES
Figure page

2-1 The location of seepage slope sites on Eglin AFB. ...........................................................25
2-2 Topographic relationship between seepage slope, upland pine, and baygall
communities including position of zones on seepage slopes. ............................................25
3-1 Topographic relationship between seepage slope, upland pine, and baygall
communities including position of zones on seepage slopes. ............................................45
3-2 The location of seepage slope sites on Eglin AFB. ...........................................................45
3-3 Percent hog-disturbed plots from 2002 to 2012. Analysis included both UF and Eglin
AFB data. ...........................................................................................................................46
3-4 Total foliar cover by year. ..................................................................................................46
3-5 Foliar cover of functional groups and A. stricta by zone (i.e., position on slope). ............47
3-6 Foliar cover of woody species through time. .....................................................................47
3-7 Foliar cover of Aristida stricta through time. ....................................................................48
4-1 Topographic relationship between seepage slope, upland pine, and baygall
communities including position of zones on seepage slopes. ............................................65
4-2 The location of seepage slope sites on Eglin AFB. ...........................................................65
4-3 Exclosure and open plot pairs. ...........................................................................................66
4-4 The location of seepage slope sites with motion detecting wildlife cameras. ...................66
4-5 Total foliar cover by intensity by year inside and outside exclosures on Eglin AFB. .......67
4-6 Total foliar cover by exclosure by year on Eglin AFB. .....................................................67
4-7 Foliar cover of woody species by intensity by year inside and outside exclosures on
Eglin AFB. .........................................................................................................................68
4-8 Foliar cover of graminoid species by intensity by year inside and outside exclosures
on Eglin AFB. ....................................................................................................................68
4-9 Foliar cover of graminoid species by exclosure by year on Eglin AFB. ...........................69
4-10 Average number of hog occurrences per month in seepage slopes with cameras on
Eglin AFB from June 2010 through December 2013. .......................................................69
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4-11 Two-dimensional nonmetric multidimensional scaling ordination showing cover by
species in high disturbance intensity and control plots on Eglin AFB. .............................70
4-12 Three-dimensional nonmetric multidimensional ordination showing cover by species
in high disturbance and control plots on Eglin AFB in A) 2010 and B) 2012. .................71
5-1 Topographic relationship between seepage slope, upland pine, and baygall
communities including position of zones on seepage slopes. ............................................88
5-2 The location of seepage slope sites on Eglin AFB. ...........................................................88
5-3 Total foliar cover by disturbance treatment over time on Eglin AFB. ..............................89
5-4 Foliar cover of forbs by disturbance treatment over time on Eglin AFB. .........................90
5-5 Foliar cover of grasses by disturbance treatment over time on Eglin AFB. ......................91
5-6 Foliar cover of woody species by disturbance treatment over time on Eglin AFB. ..........92
5-7 Foliar cover of A. stricta by disturbance treatment over time on Eglin AFB. ...................93
5-8 Foliar cover of Dichanthelium spp. by disturbance treatment over time on Eglin
AFB. ...................................................................................................................................94
5-9 Foliar cover of Sarracenia spp. by disturbance treatment over time on Eglin AFB. ........95
5-10 Species richness by disturbance treatment over time on Eglin AFB. ................................96
5-11 Three-dimensional nonmetric multidimensional ordination showing cover by species
by disturbance treatment on Eglin AFB in June 2010 and Sept 2013.. .............................97
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