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EFFECTS OF HURRICANE KATRINA ON
SOUTHERN MISSISSIPPI COASTAL FORESTS AND PROJECTED
POST-HURRICANE RESPONSES: A MULTI-SCALE EVALUATION
Research by Dr. John Kupfer
Department of Geography
To better understand how Hurricane Katrina affected
forested ecosystems in southern Mississippi and how
these ecosystems are likely to respond in the future,
University of South Carolina researchers analyzed data
on the structure and composition of different forest
community strata, conducted seed-bank germination
trials, estimated plant stress via productivity,
chlorophyll and soil redox measures, and analyzed soils
for a range of edaphic characteristics.
Researchers had three goals at the outset of this study:
1) Determine the effects of the storm surge on
coastal-zone soil chemistry 2) Estimate plant stress
related to soil changes and storm damage via measures of
plant productivity, chlorophyll, and soil redox
potential 3) Clarify the effects of forest structure,
composition, history, setting, and landscape context on
wind-caused damage patterns
 Researchers
started out with an understanding that forest recovery
after a natural disturbance is a function of the effects
of the disturbance on the existing community (e.g.,
survivorship and mortality), responses of surviving
individuals to changing and often stressful
environmental conditions based on species-specific
physiological adaptations and life history traits, and
germination and establishment of new individuals from
the soil seed bank or from seeds arriving from off-site
sources.
USC researchers initiated a multi-scale study that
combines field-based research, greenhouse studies,
remote sensing and spatial analysis. Although their
emphasis in the initial phase of this study was on the
direct impacts of the hurricane on forest ecosystems,
the researchers actually conducted two parallel studies.
In coastal forests and salt marshes located around St.
Louis Bay, they performed repeat sampling of soils to
examine the effects of the hurricane storm surge on soil
characteristics. Researchers will combine these analyses
with measures of forest structure, damage, stress, and
productivity to be taken in 2006 to clarify the
mechanical and chemical effects of storm surge on the
affected ecosystems. The second component of the study,
conducted in nearby DeSoto National Forest, used pre-
and post-hurricane forest surveys and aerial photography
to explore patterns and controls of wind-related forest
damage at scales ranging from individual trees to forest
stands to entire forested landscapes.
According to researchers, this study was only a first
step in understanding the resilience of coastal forests
affected by Hurricane Katrina, but several patterns have
already emerged. Soil samples taken one month after the
hurricane showed substantially higher concentrations of
sodium, phosphorous, magnesium, calcium and potassium,
as well as differences in pH, cation-exchange capacity,
and nitrogen in storm-surged areas. Researchers reported
that soils in areas with hydric soils (i.e.,
floodplains) have been responding differently since the
hurricane from non-hydric soils, presumably because of
different rates of leaching and other ecological
processes.
The study of wind damage is ongoing, but USC researchers
have linked patterns of damage severity to both
broad-scale controls, especially proximity to the
hurricane’s eye (a surrogate for wind speed), and
stand-level characteristics, including stand structure
and history (e.g., logging history), topography (e.g.,
floodplain vs. slope or ridgetop locations) and
composition (e.g., pine vs. hardwood components).
Researchers also reconstructed patterns and directions
of severe winds using ground surveys and aerial
photographs taken shortly after the hurricane. These
reconstructions will be used to develop and validate
models of surface wind flow patterns and predict
susceptibility of forests to future hurricanes.
Forest damage from Hurricane Katrina was caused by high
winds, with wind gusts exceeding 100 mph as far as 100
miles inland, and hurricane storm surge, which exceeded
30 feet along much of the Mississippi coastline and
penetrated more than three miles inland in some places.
The effects of the storm surge on coastal ecosystems
included mechanical damage from wave force, effects of
salt spray deposited on forest canopies above the
high-water mark, and chemical alterations of the soil
that can adversely affect coastal forests in a number of
ways. High winds damaged or destroyed billions of
dollars of timber on 5 million acres in Mississippi,
Alabama and Louisiana. Inventories indicate that
one-third of the timber damaged was concentrated in
eight counties in southern Mississippi.
 As
part of a graduate seminar, 10 USC graduate students
accompanied Dr. Kupfer and researchers from the
University of Memphis on a data collection trip to
southern Mississippi in February 2006. The USC students
helped analyze data gathered on this trip and prepare
manuscripts for publication in refereed journals. This
project created collaborations among three universities
with strong research interests in coastal ecology,
including the University of Southern Mississippi, which
was damaged by Hurricane Katrina and lost its Gulf Coast
campus. It has also fostered collaborations between the
USC Geography Department and forest managers at DeSoto
National Forest.
Results from this project are being disseminated to both
peer-reviewed professional journals as well as more
general readership outlets. Researchers are also
collaborating with the research group headed by Drs.
Fletcher and Porter on joint projects related to coastal
zone ecosystem recovery and monitoring. Researchers hope
that the study will provide insights on forest
susceptibility to hurricanes that might help to guide
forest management, both before and after future events,
in hurricane-prone areas.
On a personal note, Dr. Kupfer said that he has worked
in other areas affected by natural catastrophes such as
wildfire, but nothing could have prepared him for what
he saw along the Mississippi coastline. Nonetheless,
during his time working there, he said he was witness to
the resilience of both the people and ecosystems of
southern Mississippi.Biography
Dr. John Kupfer is a biogeographer and landscape
ecologist with an extensive background in forest
disturbance ecology and particular interests in the
interactions between spatial ecosystem pattern and
process. His work has focused on post-disturbance
vegetation dynamics and forest succession in a range of
settings throughout the United States and Central
America, with a particular emphasis on forest
heterogeneity and the impacts of forest fragmentation.
His projects typically integrate the collection of field
data on forest ecosystem attributes with geospatial
techniques, including remote sensing, GIS and spatial
analysis. He held academic positions at the University
of Utah, the University of Memphis, and the University
of Arizona before joining the Department of Geography at
the University of South Carolina as an associate
professor in 2005.
Research Team/Collaborators:
Dr. John Kupfer, Department of Geography, University
of South Carolina. Dr. Kupfer’s research integrates
field work, remote sensing, GIS and spatial analysis to
examine post-disturbance vegetation dynamics and forest
succession. Dr. Scott Franklin, Department of Biology,
University of Memphis. Dr. Franklin’s research focuses
on short and long-term responses of plant communities to
a range of natural disturbances. Dr. S. Reza Pezeshki,
Department of Biology, University of Memphis. Dr.
Pezeshki’s areas are plant stress physiology, plant
responses to environmental change, and wetland plant
ecology. Dr. Clifton Dixon, Department of Geography and
Geology, University of Southern Mississippi. Dr. Dixon’s
research focus is on historic landscape change and
environmental impacts of tourist-related development on
coastal and marine systems. |
