|
TITLE
Role of Urban Forests in Conserving and Restoring
Biological Diversity in the Lake Tahoe Basin
Study Plan
Research Project Summary
THE RESEARCH
 The conversion of wildlands to buildings, roads, and other developments
results in habitat loss and the fragmentation of associated landscapes.
Landscape fragmentation has three primary components: loss of original
habitat, reduction in habitat patch sizes, and increasing isolation
of habitat patches -- all of which contribute to a decline in biological
diversity within the original habitat. Landscape fragmentation has
a progressive and erosive effect on biological diversity and integrity,
however our understanding of how disturbance and fragmentation influence
the distribution and abundance of organisms is inadequate to effectively
manage to sustain populations in the face of fragmentation.
OBJECTIVES
To determine the effects of fragmentation and disturbance on the
occurrence, abundance, composition, and productivity of vertebrates,
vascular plants and select invertebrate species in an urbanizing
landscape.
To
evaluate the potential for landscape-level thresholds of species
persistence for select focal species based on the amount, distribution
and quality of habitat.
To
investigate the validity of species expected to be strong indicators
based on intrinsic characteristics based on empirical data.
To
develop a predictive model that evaluates the relative effects of
various acquisition, restoration, and development scenarios on individual
species, species groups, and biological diversity.
METHODS AND DESIGN
This project investigates the effects of patch-scale relationships
between patch size, isolation, and disturbance and the associated
species composition, abundance, and productivity of birds, mammals,
vascular plant, and select invertebrates. We are sampling 100 sites
along a development gradient within the lower montane zone around
Lake Tahoe. Many data collection techniques are used to characterize
the composition and abundance of vertebrate, ant, and plant species.
Specifically, we are sampling landbirds (point counts and nest monitoring),
small mammals (live trapping), large mammals (trackplate and camera
stations), ants (pitfall traps and nest counts), and plants (many
field techniques). Data are being collected in 2003-2005, with final
analysis and results available by the end of 2006.
APPLICATION OF RESEARCH RESULTS
The following management objectives will be addressed:
1. What are reliable criteria for identifying potential indicator
species?
2. Do particular species, species groups, or environmental parameters
emerge as strong indicators of biological integrity at the stand
or landscape scales?
3. How does anthropogenic disturbance within and around urban lots
affect the ability of urban lots to support their native diversity
of species? What management options exist for reducing the negative
effects of disturbance?
4. What role do urban lots play in supporting biological integrity
at the landscape scale? How might that role shift in light of various
development (i.e., build-out) scenarios within the basin?
5. What management options exist for improving the biological integrity
of existing urban lots?
6. What are the predicted effects of various stand and landscape-scale
management scenarios regarding urban lot management (i.e., development,
acquisition, restoration)?
LOCATION
The study area is the Lake Tahoe basin, located on the California-Nevada
border in the central Sierra Nevada. The Lake Tahoe basin is an
ideal setting to study of the contribution of forested parcels to
maintaining biological diversity and integrity of a larger urbanizing
landscape. The majority of development is restricted to the lower
elevation areas around Lake Tahoe, and many species of vertebrates
and vascular plants are most closely associated with these habitats.
For these low elevation associates, the high elevation crests surrounding
the basin are likely be an impediment to their dispersal, creating
closed populations that are particularly vulnerable to fragmentation
and disturbance.
LEAD SCIENTISTS/COLLABORATORS
1) Manley, Patricia N., 2)Murphy, Dennis D., 1) Campbell, Lori,
1,3) Schlesinger, Matthew D., 3) Holyoak, Marcel, 2) Merideth, Susan,
2) Arsenault, David, and 2) Sanford, Monte
1 USDA Forest Service
Sierra Nevada Research Center
2121 Second St., Suite A-101
Davis, CA 95616
ph: (703)-605-5294
2 University of Nevada
Department of Biology
Reno, Nevada 89557
3 University of California
Department of Ecology
Davis, CA 95616
PUBLICATIONS AND PRODUCTS
Parks, S.A., L.A. Campbell, P.N. Manley, and M.D. Schlesinger. In review. Modeling development as a continuum to address fine-grained heterogeneity in urbanizing landscapes. Ecological Applications.
Manley, P. N., D. D. Murphy, L. A. Campbell, K. E. Heckmann, S. Merideth, M. Sanford, and M. D. Schlesinger. 2005. Biotic diversity interfaces with urbanization in the Lake Tahoe basin. California Agriculture 60(2):59-64.
Manley, P. N. and D. D. Murphy. 2004. Roles of urban forests in conserving and restoring biological diversity in the Lake Tahoe basin: Interim Report 2003. Unpublished report. USDA Forest Service, Lake Tahoe Basin Management Unit, South Lake Tahoe, CA.
Manley, P. N. and D. D. Murphy. 2004. Roles of urban forests in conserving and restoring biological diversity in the Lake Tahoe basin: Interim Report 2004. Unpublished report. USDA Forest Service, Lake Tahoe Basin Management Unit, South Lake Tahoe, CA. |
