Browsing by Author "Dr. Thomas R. Wentworth, Committee Chair"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Mapping and Monitoring Plant Communities in the Coastal Plain of North Carolina: A Basis for Conservation Planning
    (2007-12-05) McKerrow, Alexa Jacqueline; Dr. Heather M. Cheshire, Committee Member; Dr. Jaime A. Collazo, Committee Co-Chair; Dr. Thomas R. Wentworth, Committee Chair; Dr. George R. Hess, Committee Member; Dr. Martha J. Groom, Committee Member
    The most effective tool for conservation of biodiversity is high quality information on the extent and status of species and their habitats. To guide that conservation, the National Gap Analysis Program (GAP) has been working to develop thematically rich land cover that can be used to assess the conservation status of native plant communities and as a basis for modeling the predicted distributions of species. In this research our goal was to integrate methods for developing a high quality land cover map using change detection, as the basis for monitoring plant communities and species habitats over time. We mapped the Ecological Systems of the Onslow Bight, NC using Landsat TM satellite imagery and ancillary datasets (e.g., soils). We tested the application of decision tree modeling for mapping 6 forested systems and used image objects map managed evergreen stands. A total of 42 land cover classes were mapped with an overall accuracy of 77% and a kappa statistic of .75. We then mapped the amount and type of land cover change between 1992 and 2001 using Change Vector Analysis. Change was mapped on 13% of the landscape, with an overall accuracy of 95% and a kappa statistic of .75. Using the 1992 and 2001 land cover maps we modeled the predicted distribution of 141 vertebrate species for both dates. The species had been identified by either the North Carolina Wildlife Resources Commission in their State Wildlife Action Plan (SWAP, 125 species) or by Partners in Flight (PIF, 40 species) as priority species in need of conservation action. We quantified change between the two dates and provide summaries by species and agency list. Finally we quantified the overlap in the hotspots for the predicted distributions and the existing conservation network. Sixty-eight percent of the existing managed lands in the Onslow Bight co-occur with hotspot areas for SWAP and PIF, while only 44% of the landscape met those criteria.
  • No Thumbnail Available
    Vegetation of Geographically Isolated Montane Non-alluvial Wetlands of the Southern Blue Ridge of North Carolina.
    (2009-12-04) Wichmann, Brenda Lynn; Dr. Ted H. Shear, Committee Member; Dr. Robert K. Peet, Committee Member; Dr. Thomas R. Wentworth, Committee Chair
    The ecological significance of montane non-alluvial wetlands in the southern Blue Ridge region of North Carolina is well known. However, there is relatively little quantitative documentation of these community types. In particular, our understanding of montane, peat-forming wetlands is based primarily on qualitative data, and there has been no previous comprehensive classification and description of these community types. In this study, species composition and vegetation-environment relationships are described for the geographically-isolated, non-alluvial wetlands of the southern Blue Ridge region of North Carolina. A hierarchical classification is presented for 12 community types within 2 broad vegetation classes based on 136 vegetation plots spanning the range of the southern Blue Ridge region of North Carolina. Hierarchical cluster analysis was used to delimit community types, and non-metric multidimensional scaling was subsequently used to help differentiate the community types identified by the cluster analysis. Although some of these community types fit well within currently recognized community concepts, others fit poorly within existing concepts, pointing to a need for definition of new types and/or significant refinement of types currently recognized. The 2 broad vegetation classes and 12 community types are discussed, each with a description of composition, related community concepts, and environmental context. Compositional variation among the types is most strongly associated with elevation, soil pH, soil nutrient availability, and soil cation exchange capacity.