persistence of gopher tortoises on private lands · 2011 wildlife expo, july 30, 2011 at uf-ifas...
TRANSCRIPT
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Persistence of gopher tortoises on private lands Author: Holly Ober, Department of Wildlife Ecology and Conservation (WEC), University of Florida and Vicki Underwood (former M.S. student in WEC)
L ands in private ownership will play an
increasingly important role in determining
whether or not rare species persist in regions where
privately owned land is extensive. The range of the
gopher tortoise (Gopherus polyphemus) is confined to
the Southeastern U.S., a region predominantly under
private ownership, and thus the status of this species is
largely dependent upon land management decisions
made by private landowners.
We sent an
anonymous
mail survey to
>2,500
individuals
owning
properties
≥25 acres to
evaluate
which factors were associated with gopher tortoise
occurrence on private lands in Mississippi. We had an
adjusted response rate of 23%. A greater number of
respondents reported having had gopher tortoise in the
past but not now (30%) than the number who reported
currently having tortoises on their property (19%).
Tortoises were persisting primarily on larger properties
with longleaf pine that were not managed chiefly for
timber production (i.e., they were more likely to be on
properties managed with the goal of providing
opportunities for recreation or with the goal of
providing a natural setting).
Nearly three-quarters of respondents who indicated
they had tortoises reported the presence of just 1-10
burrows on their property; only about one quarter
reported they had more than 10 burrows. This suggests
that many existing populations may be declining.
Survey results showed
that most respondents
were unaware of habitat
requirements of
tortoises and knew little
about the effects of
various land
management practices
on these animals. Few
respondents reported
they were using
management techniques
that have been shown to
benefit tortoises, such as
prescribed burning.
Most respondents (57%) were aware of wildlife
incentive programs, but were hesitant to enroll because
they did not want to commit to managing their property
in a particular manner (34%). We currently have a
publication in review that provides suggestions on
actions that may improve the likelihood of tortoise
persistence in this region, as well as changes that could
be made to incentive programs to increase landowner
participation. In particular, we recommend the
development of an education program that provides
basic information about the unique importance of
tortoises, land management practices that benefit
tortoises, the dietary needs of tortoises, and training on
the identification of tortoises and their burrows. We
also recommend that advertisement of wildlife
incentive programs emphasize the opportunity to gain
technical assistance, as our survey indicated a high
degree of interest among landowners in receiving
wildlife management advice tailored to their property.
www.sfrc.ufl.edu/CFEOR
07.08.11
Gopher Tortoise. Photo by Larry Korhnak.
Gopher Tortoise “gopher hole”. Photo by Larry Korhnak.
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2011 Wildlife Expo, July 30, 2011 at UF-IFAS West
Florida Research and Education Center, Milton, FL.
For more information please contact Ms. Robin
Vickers at ( 850) 983-5216 x 113 or [email protected]
2011 National Bobwhite Technical Committee
Meeting, August 9-12, 2011 in Tallahassee, Fl. The
meeting will be held at the Doubletree Hotel in
Tallahassee with a field trip into plantation
community of the Red Hills. For more information
please contact Charles McKelvy at
CFEOR Workshop: Landscape-scale mechanical
fuels reduction treatments effects on fire behavior,
fuel loads, and forest ecology, September, 2011 at
the Osceola National Forest in Olustee, FL. Stay
tuned for final date. To learn more go to http://
www.sfrc.ufl.edu/CFEOR/UpcomingEvents.html
Southeast Herbicide Applicator Conference,
October 3-5, 2011 at the Edgewater Beach Resort,
Panama City Beach, FL. See website for details:
http://www.conference.ifas.ufl.edu/sehac/, or
contact Johanna Gilbert, Conference Coordinator,
UF-IFAS, Office of Conferences & Institutes, (352)
392-5930, [email protected]
Longleaf pine (Pinus palustris) and hardwood dynamics in a fire-maintained ecosystem: A
simulation approach
E.L. Loudermilk, W.P. Cropper Jr., R.J. Mitchell, H. Lee (2011) Ecological Modelling 222 2733-2750.
Longleaf pine (Pinus palustris) savannas of the southeastern U.S. represent an archetype of a fire dependent ecosystem. They are known to have very short fire return intervals (∼1–3 years) that perpetuate understory plant diversity (up to 50 species m−2), support pine recruitment, and suppress fire sensitive hardwoods. Understanding the relationships that regulate longleaf and southern hardwoods is especially critical. With decreased fire frequency, insufficient intensity, or lack of underground competition, a woody mid-story rapidly develops, dominated by fire sensitive trees and shrubs that in-turn suppress more fire dependent species (including pine seedlings). This may occur in forest gaps, where pine-needle abundance is diminished, reducing fire spread potential. The interactions between longleaf pine, hardwoods, forest fuels, and fire frequency are complex and difficult to understand spatially. The objective of this study was to develop a spatially explicit longleaf pine–hardwood stochastic simulation model (LLM), incorporating tree demography, plant competition, and fuel and fire characteristics. Data from two longleaf pine study sites were used to develop and evaluate the model with the goal to incorporate simple site-specific calibration parameters for model versatility. Specific model components included pine seed masting, hardwood clonal sprouting, response to fire (re-sprouting, mortality), and tree density driven competition effects. LLM spatial outputs were consistent with observed forest gap dynamics associated with pine seedling establishment and hardwood encroachment. Changes in fire frequency (i.e., fire probability = 0.35–0.05) illustrated a shift in community structure from longleaf pine dominated to a hardwood dominated community. This approach to assessing model response may be useful in characterizing longleaf ecosystem resilience, especially at intermediate fire frequencies (e.g., 0.15) where the community may be sensitive to small changes in the fire regime. Height distributions and population densities were similar to in situ findings (field and LIDAR data) for both study sites. Height distributions output by the LLM illustrated fluctuations in population structure. The LLM was especially useful in determining knowledge gaps associated with fuel and fire heterogeneity, plant–plant interactions, population structure and its temporal fluctuations, and hardwood demography. This is the first known modeling work to simulate interactions between longleaf pine and hardwoods and provides a foundation for further studies on fire and forest management, especially in relation to ecological forestry practices, restoration, and site-specific applications.
To read the full article members click here.
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CFEOR Mission:
To develop and disseminate knowledge needed to conserve and
manage Florida’s forest as a healthy, working ecosystem that
provides social, ecological and economic benefits on a
CFEOR Administration
Bill Cleckley, Northwest Florida Water Management District, Steering Committee Chair
Tim Breault, Florida Fish and Wildlife Conservation Commission, Steering Committee Vice-Chair
Newsletter Contacts
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[email protected] Nancy Peterson, School of Forest Resources and
Conservation, CFEOR Executive Director, [email protected]
Phone 352.846.0848 ∙Fax 352.846.1277∙ PO Box 110410∙ Gainesville, FL
Ninth Symposium on Fire and Forest Meteorology,
October 18-20, 2011 in Palm Springs, CA. To learn
more go to http://www.ametsoc.org/meet/
fainst/20119fireforest.html
Mark your calendars!– Natural Areas Conference
on November 1-4, 2011. An exceptional conference
experience! Located in the Florida Panhandle, the
unique landscapes will provide an exciting
conference setting and diverse field trip
opportunities. The Florida State University
Conference Center offers a state-of the-art venue to
share research through numerous technical
symposia as well as thought-provoking invited and
contributed plenary and paper sessions on
stewardship, management and research. The
extensive program also features special sessions
including an all-day Cogengrass workshop and State
and Federal Natural Area Roundtables; our co-host
NAEPPC will feature dedicated tracks for sharpening
-the-saw in invasive species management. View the
call for papers at http://www.naturalarea.org/
NaturalAreasConferenceAnnouncement.asp
Exploring the Mega-fire Reality 2011: A Forest
Ecology and Management Conference, November
14-17, 2011 in Florida, USA. To learn more go to
http://www.megafirereality.com