Grantee Research Project Results
Bridging Science With Management: Optimizing Habitat Quality for Black Bears on a Landscape Level by Manipulating Spatio-Temporal Parameters of ClearcutsEPA Grant Number: U916206
Title: Bridging Science With Management: Optimizing Habitat Quality for Black Bears on a Landscape Level by Manipulating Spatio-Temporal Parameters of Clearcuts
Investigators: Reynolds, Melissa J.
Institution: Auburn University Main Campus
EPA Project Officer: Cobbs-Green, Gladys M.
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $90,472
RFA: STAR Graduate Fellowships (2003)
Research Category: Fellowship - Terrestrial Ecology and Ecosystems , Academic Fellowships , Ecological Indicators/Assessment/Restoration
The objectives of this research project are to: (1) improve our understanding of how clearcuts affect habitat quality for black bears (Ursus americanus) in the Southern Appalachians; and (2) use this information to develop optimization models that can be used to design landscapes that maximize habitat quality for black bears by manipulating when and where future clearcuts are implemented.Approach:
This research is part of a continuing 22-year study that is being conducted in the Pisgah Bear Sanctuary in North Carolina. To understand how clearcuts affected habitat quality during 1981-2002, we will test an existing a priori, spatially explicit model of habitat quality for black bears (model Q) against two competing models that we developed. For one alternate model (model Qtime), we expanded model Q to include information on how habitat quality in clearcuts changes through time. We measured availability of resources (foods, den sites, and escape cover) within 50 young clearcuts (0-40 years old) that were randomly selected from an age- and aspect-stratified sample and within 212 older clearcuts (41+ years old) that were systematically selected. For the second competing hypothesis (model Qtime+space), we modeled habitat quality in clearcuts as a function of both temporal changes because of succession and the spatial context within which clearcuts were located. We generated habitat quality maps for Pisgah Bear Sanctuary for each year from 1981 through 2002 with a geographic information system (ArcView 3.2a and Spatial Analyst 2.0) using each of the three models, Q, Qtime, and Qtime+space. Each resource variable contained within the different Q models was calculated for every 30 by 30 meter cell of a grid that was superimposed on the Sanctuary. Subsequently, these values were combined in equations defined by each Q model. We will test each hypothesis with utility distributions calculated from location data collected from 55 female bears over 22 years. The model that best fits the data will be used to develop models that optimize habitat quality on the landscape by manipulating where and when clearcuts are implemented. Finally, we tested an underlying assumption of our habitat selection study (i.e., a clearcut is important to fitness if it is selected) by evaluating demographic response of Pisgah bears to annual availability of clearcuts. We linked annual estimates of availability of clearcuts with annual estimates of survival, fertility, and population growth rate that we calculated in Program MARK using the temporal symmetry parameterization. This research project should provide an improved understanding of how clearcuts affect habitat quality for black bears in the Southern Appalachians and the development of a management tool for optimizing habitat quality for black bears on forested landscapes.Supplemental Keywords:
fellowship, black bears, Ursus americanus, clearcuts, demography, habitat quality, landscape modeling, optimization, timber harvesting, forested landscapes, Southern Appalachians, Pisgah Bear Sanctuary, North Carolina, NC.