
|
James Dyer
Professor of Geography
Graduate
Student
Theses
Abstracts
|
Gary
Conley, 2013. Examining the Cover and Composition of the
Successional Vegetation Mosiac of Pre-SMCRA Mined Landscapes in
Southeast Ohio.
This
research examined 10 similar surface coal mines in southeast
Ohio to assess the factors broadly influencing the cover and
composition of the successional vegetation mosaic. Transects
were surveyed on opposing north- and south-facing aspects within
each mine to comprehensively characterize the vegetative
community. Statistical analysis strongly indicated that measures
of vegetation cover were almost exclusively associated with
edaphic properties such as soil pH and electrical conductivity.
In clear contrast, species richness and the composition of the
vegetative community were influenced primarily by physical
landform features and the size and shape of mine extents. While
some features of surface mines may act as barriers to the
dispersal of native species, the element of distance is the
primary limitation to natural succession. Areas furthest from
the functional edge seem to be more readily occupied by
non-native species once conditions improve, representing a
missed opportunity for native establishment and may act as a
barrier to future establishment of natives. These results may
begin to simplify issues for understanding the long-term
recovery of mine lands, in terms of the goals of reclamation and
restoration. Furthermore, it highlights the need for
incorporating more ecologically-based objectives and practices
into landscape planning and management.
Nathan
Daniel, 2012. American Chestnut Restoration in Eastern
Hemlock-Dominated Forests of Southeast Ohio. [Brian
McCarthy,
co-advisor]
Restoration
of
American chestnut (Castanea
dentata
(Marsh.) Borkh.) is currently underway in eastern North American
forests. American chestnut and eastern hemlock (Tsuga canadensis (L.)
Carr.) trees
historically co-occurred in these forests. Today,
hemlock-dominated forests are in decline due to hemlock wooly
adelgid
(Adelges tsugae Annand) infestation, and as such, may serve as
appropriate habitat for chestnut reestablishment. To
investigate
this notion, I evaluated the performance of American chestnut
seedlings
planted under healthy eastern hemlock-dominated canopies.
Two
process-oriented greenhouse experiments were also performed to
study
the response of American chestnut to drought stress and to test
the
competitive performance of chestnut against red maple (Acer rubrum (L.)), the most
abundant hardwood found in the understory of regional
hemlock-dominated
forests. After two growing seasons, mean chestnut seedling
survival in the field experiment was 6.6%. Seedling
survival was
significantly higher among trees that lacked a protective tree
tube,
suggesting low light levels played a major role in seedling
mortality. In the drought stress experiment, American
chestnut
exhibited significantly higher mortality under a severe drought
treatment compared to the control group. The moderate
stress
treatment also responded poorly to drought; however, results did
not
differ significantly with the control group. In the
competition
experiment, American chestnut grew significantly taller than red
maple. The results of this study caution against the
underplanting of bare-root chestnut seedlings in low light
conditions
or where moisture may be limiting to establishing
seedlings. The
results also validate the classification of American chestnut as
an
aggressive understory competitor, when environmental conditions
are
appropriate.
Jason
Brown, 2010. Spatial
Distribution
of Freshwater Mussels (Unionidae) in Ohio Brush Creek
Watershed, Southern Ohio.
Between
July
and
October 2005, 42 sites across Ohio Brush Creek watershed were
surveyed to assess the spatial distribution of native freshwater
mussels (Unionidae). Freshwater mussel shells were
recorded at 28
out of 42 sites representing 14 native species. A total of
thirteen species were recorded at 19 sites as living or fresh
dead. Associations between the presence, diversity, and
abundance
of freshwater mussels and coarse-scale variables (drainage area,
stream
gradient, and percent land cover) and fine-scale variables (200
meter
stream-reach habitat features based on Ohio EPA’s Qualitative
Habitat
Evaluation Index (QHEI)) were explored using correlation and
chi-square
analysis. The presence, diversity, and abundance of mussel
shells
were associated with both coarse and fine scale variables.
Drainage area and stream reaches with excellent channel
development,
high amounts of habitat cover, maximum water depths > 1
meter, and
riffle depths > 5 cm were all associated with the presence,
diversity, and abundance of mussels. Stream gradient was
also
associated with mussel shell presence and diversity, however was
not
associated with shell abundance due to the high abundance of fat
mucket
shells in upper reaches of the watershed. Sites with the
highest
diversity and abundance occurred along the mainstems of Ohio
Brush
Creek and the West Fork. Thirty-seven native mussel
species have
been recorded in the watershed. Unfortunately over 40% of
these
species are listed as either endangered, threatened, or of
special
concern. Sedimentation due to agricultural runoff and
deforestation of riparian corridors has been identified as the
primary
threat to freshwater mussels in Ohio Brush Creek
watershed. It is
imperative to collect data that can be explored to find spatial
and
temporal patterns that exist amongst the mussel community in
Ohio Brush
Creek watershed. This data can also be used to help guide
stream
habitat restoration and native mussel re-establishment projects
in the
watershed.
Loredana
Suciu,
2009. Microclimatic
and
Topographic
Controls
of Fire Radiative Energy in Southeastern Ohio.
This
study
explores
the
environmental
control of two key elements of water
balance on fire behavior at two sites in southeastern Ohio, Arch
Rock
and Tar Hollow. The two elements of water balance are potential
evapotranspiration (PET) and actual evapotranspiration (AET).
Fire
behavior is expressed in this study as fire radiative energy
(FRE),
which is estimated from time-sequence fire radiative power by
remote
sensing of infrared radiation during fires. Previous studies
have shown
that both fuel moisture and fuel load are primary driving forces
of
fire behavior at a coarse scale. Therefore, in this study, PET is used to suggest fuel
moisture in spring and AET is used as a surrogate for
productivity
during the growing season in order to explain FRE at a fine
scale.
Results show that a water balance approach helped to explain FRE
using
categorical AET and PET. At the pixel level, the water balance
approach
was less successful because the variables did not relate
reasonably
with space and because of other fine-scale local effects
(hydrology,
decomposition rates) that were not captured by PET and AET.
Aspect
strongly influences solar radiation and PET. Thus, aspect was
used
additionally to assess its indirect effects on FRE. Overall, FRE
responded well to aspect at both study sites.
Nicole
Stump, 2008. Ecological
Considerations
for
Risk
Management of the Hemlock Woolly Adelgid in the
Hocking Hills, Ohio USA.
The
eastern
hemlock (Tsuga canadensis) forests that inhabit
the cool moist ravines of
the Hocking Hills in southeastern Ohio are in the projected path
of the
hemlock
woolly adelgid (Adelges tsugae).
This
introduced
pest
has
destroyed entire
eastern hemlock stands, including mature old-growth forests, and
drastically
altered ecosystems. A summary of
available knowledge about the ecological significance of eastern
hemlock as
well as considerations for managing pest populations of the
hemlock
woolly
adelgid is presented. Geographic
Information System (GIS) techniques combining high-resolution
aerial
imagery
and ancillary information such as topographic position and soil
were
applied to
map the spatial extent of Eastern Hemlock on the landscape. Baseline information about the
structure and
composition of local Eastern Hemlock forests, as well as the
dynamics
of the
stands and growth trends are established through a
dendroecological
analysis of
core samples and plot inventories.
Recognizing the need to understand the spread of HWA and
the
possible
significant role of migratory birds in dispersal, a survey of
birds
associated
within the hemlock stands via call recordings was conducted. The objective of this research is to
add to
the scientific knowledge of local eastern hemlock forests and to
promote
proactive pest management strategies and improved monitoring for
early
detection.
Lisa
King, 2008. Using
Landscape
Variables
to
Assess Stream Health in Ohio’s Western Allegheny
Plateau.
For
twenty
years
the
Ohio
EPA has
characterized stream health using fish and macroinvertebrate
community
assemblages, as well as by local habitat within the stream.
Since the
adjoining landscape may also influence stream health, this
research
explores a variety of easily attainable GIS land use/cover,
population,
and forest connectivity data to find which best correlate with
stream
health. Four different metrics (percent native fish,
darters/sculpins,
intolerant, and sensitive species) were evaluated against
forty-eight
different independent variables using multiple regression. Three
variables were important for predicting stream health: density
of
abandoned mine openings in the upstream catchment, forest
connectivity
in a 66 ha area surrounding the sample point, and percent
wetlands
(from NLCD) within the HUC-14 subwatershed. Percent forest cover
(GIRAS) in the upstream riparian buffer was also important for
intolerant species. Despite known macro- and micro-controls on
fish
communities, landscape variables were able to explain up to half
the
variance in these fish metrics.
Scott
Snider,
2004.
Predicting
Infestations
of Hemlock
Woolly Adelgid (Adelges tsugae)
in
Great
Smoky
Mountains
National Park Tennessee/North
Carolina, USA.
The
hemlock
wooly
adelgid
(Adelges tsugae) is a
non-native, invasive pest killing eastern hemlock (Tsuga
canadensis) trees in the
eastern United
States.
The purpose of this research is to evaluate wind and people as
dispersal
mechanisms and the factors limiting spread of the adelgid in Great
Smoky Mountains National Park. The results from binary
discriminant analysis
indicate that people have the biggest influence on spreading
HWA, wind
was not
a significant factor of dispersal, and cold temperatures can
limit the
range to
which it will spread. This information
can be applied in the fight against the adelgid because it can
help to
define a
search area with a higher probability of infestation and to
define
monitoring
and treatment standards for these areas.
Kaabe
Shaw,
2002.
Exotic
Plant
Colonization
of
the
Forest
Adjacent to Transmission Line Corridors in Athens
County, Ohio.
The
colonization
of
exotic species in forested areas is a growing concern to the
biological
diversity of our forests. It is known that exotic species are
more
common in
highly fragmented, disturbed landscapes (e.g. forested landscape
with
transmission line corridors present) with higher levels of
light,
temperature
and photosynthetically active radiation. This study concentrates
on the
colonization of exotic species along the transmission line
corridor/forest
edge, and their ability to spread into the forest interior. In Athens
County, Ohio, a
landscape has been created in which exotic species can
potentially
use transmission line corridors as a conduit to move along the
corridor
as well
as from the corridor to the forest. Edge
or
interior position, aspect (cool or warm) and topographic
position
(ridge or
valley) are environmental factors that may affect the ability of
exotic
species
to move along the corridor/forest edge, then spread into the
forest
interior by
providing environmental conditions favorable to the exotic
species.
Overall,
90
pairs
(one
ridge
or
one valley) of sites were sampled. At each of these 180
sites,
plots were established on warm/cool aspects, and at forest
edge/interior,
resulting in 720 sample sites. At 2 and 30 meters inside the
forest on
each
side of the corridor, nested circle quadrats of 1-m2
for
herbs and
5-m2 for shrubs and trees were constructed and
percent cover
per
species was estimated using the Modified Daubenmire Scale. A
Principal
Coordinates
Analysis (PCO) was performed, and PCO scores then served as
input to a
MANOVA
to determine if there is a significant difference in exotic
species
abundance
from edge or interior position, warm or cool aspect and ridge or
valley
topographic position (interactive effects of the three
environmental
variables
were also analyzed). MANOVA results
indicate that edge or interior position and an interactive
effect of
edge or
interior position and aspect significantly influence the
abundance of
exotic
species. Although not statistically significant, topographic
position
may also
play a role in the abundance of exotic species. Potential
exotic
species
colonization
and
displacement
of native interior species may increase in a forested
landscape
that is dissected by transmission line corridors. Eradication
and
prevention of
further exotic species colonization may be the best solution to
control
exotic
species from dominating local forests.
Galo
Zapato-Rios,
2001.
Linking
Spatial
Data
with
Population
Viability Analysis: Reserve Network Design in the
Northeastern
Ecuadorian Amazon.
This
research
evaluates
the
effectiveness
of two
protected
areas of the northeastern Ecuadorian Amazon (Cuyabeno Fauna
Production
Reserve
and Yasuní
National Park) in protecting wildlife
populations in the long-term. Because, currently, there are no
methods
to
determine the efficiency of protected areas with reference only
to
ecosystem
characteristics, five large mammal species were chosen as
indicator
species (Myrmecophaga
tridactyla, Ateles
belzebuth, Alouatta
seniculus, Panthera
onca, and Tapirus
terrestris).
The methodology combined remote sensing, geographic information
systems, and
population viability analysis in order to estimate the current
carrying
capacity of the protected areas and the extinction probability
of the
indicator
species during the next one hundred years. The results suggest
that
individually Cuyabeno and Yasuní cannot be considered
efficient
because, under
current management conditions, they do not protect minimum
viable
populations.
Persistence probability is higher if migration and gene flow are
allowed
between the protected areas. Finally, a reserve network joining
Cuyabeno and
Yasuní with a biological corridor was designed to
increase the
conservation potential
of both areas.
Michael
Wehling,
2001.
Land
Use Land
Cover Change From 1915 to 1999 in The Gwynns
Falls
Watershed, Baltimore
County, Maryland:
Creation
of
a
Suburban Social Ecology.
(Click
here
to view a summary with figures.)
The
study
describes land use land cover (LULC) change in the
Gwynns Falls Watershed of Baltimore County, Maryland during the
20th
century. Procedures include (1) mapping
the extent of LULC change by integrating air photos from 1938,
1957,
1971 and
1999, with a digitized forestry map from 1915 into a GIS, (2)
performing
landscape pattern analysis on forest cover for each year, and
(3)
overlaying
LULC maps in the GIS to determine change over time.
LULC categories mapped were Urban-High Tree
Density, Urban-Low Tree Density/High Permeability, Urban-Low
Permeability,
Agriculture, Old Field & Pasture, Forest,
Water, and
Transitional. Minimum mapping unit is 1
ha.
The Gwynns Falls Watershed
transformed
from an area covered
by relatively equal proportions of Agriculture, Old
Field/Pasture, Forest,
and Urban-Low Permeability surfaces, to an area dominated by
Urban-Low
Permeability surfaces during the 20th century.
From 1938-1957, 46% of the landscape in the
common study area changed, 37% change in LULC occurred
1957-1971, and
35% of
LULC changed 1971-1999. Transitions in
agriculture allowed the expansion of forest cover onto old
fields,
similar to
the pattern seen elsewhere in the eastern deciduous
forest.
Increasing development reduced and dispersed
the Forest patches, potentially affecting
species
persistence and dispersal.
Through simultaneous and
sequential
changes in agriculture,
forest structure, preservation, and urban expansion, both
sociocultural
and
biophysical processes transformed the LULC of the Gwynns Falls
Watershed. Further inquiry into these
reciprocal
relationships will aid in understanding their functioning and
management.
Emily
Whitfield,
1998.
The
Biogeography
of
Gapper's
Red-backed
Vole (Clethrionomys
gapperi):
A
Comparison
of
Genetic and Morphological Variation in Eastern
North
America.
Species
located
in
habitat
islands
tend
to show similar isolation effects to those found
on true
islands. The isolation often causes a reduction in fitness
usually
directly
related to decreased genetic variation. The study species, Clethrionomys
gapperi,
Gapper's red- backed vole, is a boreal species restricted to
mountaintops
in the southern part of its range. Populations of C.
gapperi
from eastern North America were examined for evidence of
this
reduction
in variation through both genetic and morphological means.
Tissue from
live-
trapped voles from New
Hampshire, West
Virginia,
and Tennessee was analyzed for heterozygousity
using
microsatellite primer pairs. Bilateral characters on skulls from
four
museum
collections were measured and then used in a comparison of
fluctuating
asymmetry levels among different groups. The DNA analysis
reveals that
populations found in the south had a lower number of banding
patterns
in the
southern populations, both within an individual population and
overall.
Morphological
analysis of skulls for evidence of fluctuating asymmetry reveals
higher
levels
of fluctuating asymmetry for more southern populations. As high
levels
of
fluctuating asymmetry are often related to low levels of genetic
variability,
these results are in agreement with the genetic analysis that
the
southern
populations had lower levels of genetic variability. The
southern
mountaintops
are therefore acting as habitat islands, isolated from each
other and
the more
northern "mainland", and have the expected reduction in genetic
variation in the isolated populations.
Evan
Moffett,
1997.
Landscape
Suitability:
A
Case
Study
of Wolf Habitat in North
Dakota.
The
wolf
is
identified by the federal government as endangered in the 48
contiguous
states,
excluding Minnesota where it is listed as threatened;
North Dakota's Turtle Mountain pack is listed
endangered. Over the past two
decades, a relationship has been identified in the Great Lakes
Region
between
wolf presence/absence, road density and human population
density. Road
density,
in particular, has been described as a "yardstick" to measure
habitat
suitability, resulting in the use of this variable in recovery
efforts.
Road
density and human population density together serve as
surrogates for
human
access to the species. Access, resulting in poaching, increases
the
difficulty
in preserving this keystone species
The objective of
this thesis is to examine fine-grained habitat suitability
throughout
the state
of North Dakota.
The anthropogenic factors examined include human population
density and
road
density. This thesis reclassifies the state based on parameters
from
North
Rolette Unorganized, the minor civil division (MCD) in the Turtle Mountains
in which wolves are denning. In addition,
this thesis examines the importance of prey biomass on potential
wolf
numbers
and the significance of spatial scale in defining habitat.
Results suggest the
following: (1) large areas of habitat exist within North Dakota
in
which human
population density and road density are low; (2) models of
habitat
suitability
for wolves are formation specific; differences exist as to
threshold
values
from the GLR (forest type formation) and North Dakota (prairie
formation); (3)
differences between the MCD and county spatial scale exist with
regards
to wolf
habitat suitability in North Dakota; (4) no predictive model can
express wolf
habitat adequately as long as humans continue to view this
endangered
species
as destructive. Based on the variables examined, the state of North
Dakota
can support a wolf population. As indicated
by numerous authors, wolves will not successfully reestablish
their
former
range so long as people destroy them.
Lisa
DeChano,
1997.
Catastrophic
Windthrow:
A
Case
Study of the Allegheny
River Wilderness
Islands.
On May
31, 1985,
a series of tornadoes ripped through
the Allegheny National Forest, in northwestern Pennsylvania. One of the tornadoes, an F4, hit
Baker Island, an Allegheny
River Wilderness Island, and
the surrounding upland. This thesis
investigates the woody species regeneration of this riparian
site as it
compares with the eastern and western upland sites, eleven years
after
the
devastating natural event.
From aerial
photographs, three distinctive areas were chosen for sampling on
Baker Island and
both sides of the Allegheny River: (1) an undisturbed zone, (2) a
disturbed
zone, and (3) a transitional zone (a designated "edge" area in
the
upland sites). Island sampling used belt transects consisting of
contiguous
20x50m (1000 m2 quadrats, while the upland sites were
sampled with a
single 20x50m quadrat in each area, for all trees (h ≥10cm dbh)
and
large
saplings (h ≥ 2m, <10cm dbh). The small saplings and
seedlings were
sampled
inside a nested 5x10m (50m2) quadrat and a 2x5m (10m2)
quadrat,
respectively,
on
the upland sites and within a 1x1 m (1m2)
quadrat on Baker Island. Species identification and
counts were
taken at all sites and dbh measurements were recorded for trees
and
large
saplings. Ordination, TWINSPAN, and cluster analysis helped
determine
if the
regeneration processes were similar between each area.
Results indicate
that
succession is proceeding on the upland sites; early successional
species
dominate the eastern and western uplands, such as sassafras and
quaking
aspen.
Beech has a significant presence in the understory on the
upland. In
contrast, Baker Island has no regeneration occurring,
with the
exception of a few patches of choke cherry and American elm. The
main
reason
suggested for the limited recovery of woody species on the
island is
reed
canary grass. It dominates the understory everywhere on the
island,
suppressing
any seedling growth that might establish.
Basal area and
density decreased in all areas, which is expected after a
tornado of
this
intensity. Within the disturbed areas there was no selectivity
in which
trees
were damaged. Everything in the path of the tornado was either
snapped
or
uprooted. A species-specific response did occur on Baker Island as
the damaged lessened, however. Based on
existing evidence, silver maple suffered more snapping, while
sycamore
was more
likely to uproot.
Riparian
environments
are very unique and have not been studied as deeply as upland
forest
areas have
been. This study is significant in helping to bridge the gap in
the
literature
in how a riparian system responds to a natural disaster of this
intensity. It
also adds to the body of knowledge already established
concerning
upland forest
recovery from a devastating tornado.
Ian
Kitch,
1994.
A
Spatial
Analysis
of
an Urban Fishery: A Case Study of Winnipeg,
Manitoba.
With
increasing
population
and
urbanization,
the need for
understanding
resource users and the environment in which they reside is
necessary
for proper
management of urban fisheries. For urban residents to enjoy
nature
within city
limits, managers must plan for aquatic amenities such as fishing
and
other
aquatic activities.
Understanding the
needs
of the fishery user
ultimately will help
managers to increase the quality of the resource and life in the
city.
The
purpose of this study was to identify the key resource concerns
and
attitudes
of anglers of a fishery located in Winnipeg, Manitoba, Canada.
The spatial variations within the city and
analysis of data in terms of accessibility, use, and perception
was the
focus
of the study.
The user base
was
sampled by conducting
269 personal interviews from
May to August over three distinct areas of the city (Red River south of the
forks, Red
River
north of
the forks, and Assiniboine River). The
results revealed that there were two
primary spatial variations in perceptions of Winnipeg
anglers. Firstly, water quality concerns
were highest in the North area of the city and secondly, safety
concerns were
greatest in the Assiniboine area.
The current
managers of
the resource will use
the results to assess
urban fishing strategies within Winnipeg. Urban
fishing studies are important to
managers and planners because with the knowledge of the user
base and
the resource,
the fishery can be enhanced, promoted, and protected.
Back
to
Main
Page