PARENT SESSION
Oral Session 8: Forest Ecology I: Dynamics and Succession.
Presiding: A Fiala and D Kashian
Monday, August 2, 8:00 AM to 11:30 AM, Meeting Room B 117.
Leave islands as refugia for low-mobility species in managed forests of the Pacific Northwest.
Wessell, Stephanie*,1, Schmitz, Richard1, Olson, Deanna2, 1 Oregon State University, Corvallis, OR, USA2 USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, USA
ABSTRACT- In recent years, forest management in the Pacific Northwest (U.S.A.) has shifted from one based largely on resource extraction to one based on ecosystem management principles. Forest management based on these principles involves simultaneously balancing and sustaining multiple forest resource values, including silvicultural, social, economic, and ecological objectives. Leave islands, or green tree retention clusters, have been proposed as an alternative silvicultural strategy designed to sustain the ecological integrity and biological diversity of managed forests. However, pertinent questions regarding the relationship of the physical structure of leave islands to their associated microclimates, flora, and fauna remain largely unanswered. This study evaluates the effectiveness of three sizes of leave islands within a thinned forest matrix relative to thinned and unthinned forest in providing refugia for low-mobility, ecologically-sensitive species one to five years following timber harvest. Specifically, we are examining differences in microhabitat and amphibian, mollusk, arthropod, and vascular plant abundance and diversity with respect to the size of leave islands in managed forests. By determining habitat correlates of species and functional group occurrence, we envision that this study will provide vital information regarding leave islands in managed forest landscapes. Initial results indicate treatment effects relative to microclimate, amphibian and arthropod density, and vascular plant diversity and ground cover. These results suggest that leave islands may provide short-term refugia for some low-mobility, ecologically sensitive species in managed forests of the Pacific Northwest.
Key words: forests, microclimate, reserves, biodiversity