Scale Specific Management Legacies in Patterns of Spruce Budworm Host Species in the Border Lakes Region
Event Website
http://www.nafew2009.org/
Start Date
6-23-2009 8:40 AM
End Date
6-23-2009 9:00 AM
Description
The spruce budworm (SBW) is a native defoliator of fir and spruce forests in Canada. Increases in the extent and severity of SBW outbreaks over the last century may be due to changes in forest composition and configuration as a result of forest management. Better understanding of long term interactions between human and natural disturbance processes is essential to sustainable forest management. Using the Border Lakes Landscape (BLL) of northern Minnesota and north-western Ontario as a case study, we investigate whether differences in spatial patterns in SBW host species can indeed be attributed to regional differences in forest management. The BLL contains three zones of historical management: (1) fine scale management in Minnesota, (2) coarse scale management in Ontario, and (3) no management in a wilderness region comprised of the Boundary Waters Canoe Area and Quetico Provincial Park. Multi-temporal LANDSAT data representing species composition and basal area were analyzed using spatial pattern metrics and wavelets to better understand the role of management legacies on host species spatial structure. Results indicate that forest composition and host species basal area are finely structured over the entire BLL and strongly constrained by patterns of lakes and wetlands. Patch metrics indicate larger patches and a larger proportion of mixed wood forest in the unmanaged region between the actively managed regions of Ontario and Minnesota and smaller patches of deciduous forest in the wilderness and Ontario regions. Wavelet analysis revealed fine scale spatial structure in host species across the study region. Some support was also found for the existence of locally significant regions of host species basal area that correspond to political boundaries in the BLL demonstrating the potential influence of forest management on insect disturbance dynamics.
Scale Specific Management Legacies in Patterns of Spruce Budworm Host Species in the Border Lakes Region
The spruce budworm (SBW) is a native defoliator of fir and spruce forests in Canada. Increases in the extent and severity of SBW outbreaks over the last century may be due to changes in forest composition and configuration as a result of forest management. Better understanding of long term interactions between human and natural disturbance processes is essential to sustainable forest management. Using the Border Lakes Landscape (BLL) of northern Minnesota and north-western Ontario as a case study, we investigate whether differences in spatial patterns in SBW host species can indeed be attributed to regional differences in forest management. The BLL contains three zones of historical management: (1) fine scale management in Minnesota, (2) coarse scale management in Ontario, and (3) no management in a wilderness region comprised of the Boundary Waters Canoe Area and Quetico Provincial Park. Multi-temporal LANDSAT data representing species composition and basal area were analyzed using spatial pattern metrics and wavelets to better understand the role of management legacies on host species spatial structure. Results indicate that forest composition and host species basal area are finely structured over the entire BLL and strongly constrained by patterns of lakes and wetlands. Patch metrics indicate larger patches and a larger proportion of mixed wood forest in the unmanaged region between the actively managed regions of Ontario and Minnesota and smaller patches of deciduous forest in the wilderness and Ontario regions. Wavelet analysis revealed fine scale spatial structure in host species across the study region. Some support was also found for the existence of locally significant regions of host species basal area that correspond to political boundaries in the BLL demonstrating the potential influence of forest management on insect disturbance dynamics.
https://digitalcommons.usu.edu/nafecology/sessions/disturbance/5