Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Wood Science and Technology
Petra Bohall Wood.
I conducted 50-m fixed radius point counts and monitored nests at the Wildlife and Ecosystem Research Forest (WERF) and Panther Run Tract in Randolph County, WV, from 2007--2009 and incorporated previous research using the same techniques from 1996--1998 and 2001--2003.;In chapter two, my objectives were to identify temporal abundance and nest success trends and identify landscape-scale disturbance thresholds for species and habitat guilds using a variety of harvests. Early successional species increased in relative abundance, while interior-edge and forest-interior guilds peaked in relative abundance mid-study, after which the forest-interior guild declined. Of 44 analyzed species, 9% declined, 36% increased, and 32% peaked in abundance mid-study. Forest-interior and interior-edge guilds exhibited thresholds, a disproportionate response in bird abundance relative to a small change in habitat results, at 28% of the landscape, 10% harvesting by clear-cuts, and 18% harvesting by light partial harvests, after which abundances declined. Thresholds for the early successional guild were greater for total harvests (42%), similar for harvesting by clear-cuts (11%), and smaller for light partial harvests(10%), for which relative abundances increased after surpassing thresholds except for a reduction in the rate of increase for clear-cuts. Even though abundance of most species (82%) did not decline as the area affected by timber management increased, implementing management at or below our approximate harvest thresholds for forest-interior and interior-edge guilds would reduce the number of declining species by half.;In chapter three, my objective was to use the broader spectrum of habitat conditions resulting from long-term management to categorize bird species into habitat groups, identify habitat commonalities between group members, and determine habitat conditions associated with successful nests. Using non-metric multidimensional scaling (NMDS), I identified four habitat groups: mature forest, disturbed-canopy low elevation, disturbed-canopy high elevation, and early succession. Early successional species increased in abundance with greater amount of clear-cuts, heavy partial harvests, and edge density. The two disturbed-canopy groups (divided based on elevation) had no consistent metrics among species, but included variables representing different aspects of disturbed mature forests. Mature (undisturbed) forest species declined in abundance with increased clear-cuts, core early succession habitat, and habitat intermixing and reduced shape complexity. Nest success models had high error due to small sample sizes; still, they suggested different conditions are required for successful breeding than for high abundance. My results highlight the need to reconsider the classification of bird species with respect to habitat created by timber management. Group members shared many habitat commonalities and model error was improved over traditional habitat guilds, but variation remains among most species within these groups.;In chapter four, my objectives were to evaluate the response of Canada Warbler (CAWA) abundance and nest success to habitat characteristics as they changed due to forest management practices. According to the Breeding Bird Survey (BBS), the abundance of this declining species has been stable in the Appalachian Bird Conservation Region (BCR), suggesting this region may make important contributions to the species' conservation; however, off-road point count results indicate that CAWA relative abundance decreased on the WERF and the Appalachian BCR, but at lower yearly rates on the WERF. Early in the study, relative abundance was greater closer to roads, but as timber harvest became more common, it was positively related to area of light partial harvests at the local scale. Overall, relative abundance responded positively to all three types of timber harvests. Nest success did not differ between 1996--1998 and 2007--2009. Nests in 2007--2009 had less intermediate canopy cover and residual trees but more green cover, woody debris, and pole trees than nests in 1996--1998. Successful nests had more low cover, less vertical diversity, more woody debris, more saplings, and greater edge density than unsuccessful nests. My research finds preliminary support for use of timber harvests management tool for Canada Warblers in the southern portion of their range with the need for long-term monitoring of abundance and nest success to confirm successful management. (Abstract shortened by UMI.).
Becker, Douglas, "Long-term effects of timber management on forest breeding songbirds in the central Appalachians" (2010). Graduate Theses, Dissertations, and Problem Reports. 3188.