Response of black bears to gypsy moth infestation in Shenandoah National Park, Virginia
| Autor: | Kasbohm, John W. |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: | |
| Druh dokumentu: | Dissertation |
| Popis: | The effects of gypsy moth infestation on the Shenandoah National Park (SNP) black bear population and habitat were studied during 1985 - 1991 by comparing radio telemetry, population, and behavioral data from preinfestation years (1982 - 1986) and years with extensive defoliation (1987 - 1991). Gypsy moth defoliation (> 60% canopy loss) increased from 546 ha in 1986 (1 % of the study area), to 2,304 ha in 1987 (4%), 6,227 ha in 1988 (12%), and 17,736 ha in 1989 (34%). Chestnut oak and red oak habitat types received the greatest defoliation; 60% and 45% of these habitat types suffered greater than 60 % canopy loss in the North and Central Districts, respectively. Infestation resulted in a 99% reduction in acorn production in defoliated stands. Maximum daily temperatures 0.5 m above the ground in defoliated stands averaged 4.7 ± 0.3 C, 4.3 ± 0.4 C, and 2.5 ± 0.3 C warmer (P < 0.01) than in nondefoliated stands during peak defoliation, refoliation, and post-refoliation periods, respectively. Bear Ph. D. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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