Influences of Past and Future Forest Management on the Spatiotemporal Dynamics of Habitat Supply for Canada Lynx and American Martens in Northern Maine

The American marten (Martes americand) prefers habitats with complex physical structure associated with mature, closed-canopy forest, which provides protection from predators, resting sites, and access to prey. Previous research has concluded that timber harvesting can negatively influence marten de...

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Bibliographic Details
Main Author: Simons, Erin M.
Format: Text
Language:unknown
Published: DigitalCommons@UMaine 2009
Subjects:
Online Access:https://digitalcommons.library.umaine.edu/etd/1544
https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=2573&context=etd
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Summary:The American marten (Martes americand) prefers habitats with complex physical structure associated with mature, closed-canopy forest, which provides protection from predators, resting sites, and access to prey. Previous research has concluded that timber harvesting can negatively influence marten density, and clearcut harvesting has been implicated in local population declines. Studies also suggest that martens may be particularly sensitive to habitat loss, predicting a steep decline in probability of home range occupancy in response to a small decline in percent suitable habitat. Little is known, however, about the cumulative effects of habitat loss and fragmentation on habitat supply for martens or the spatiotemporal dynamics of probability of occurrence for martens in a managed landscape. I developed a spatially-explicit time series of marten habitat, derived from satellite imagery, to evaluate effects of forest management on quantity and distribution of marten habitat, on spatiotemporal patterns of marten occurrence, and on estimated densities of martens in a dynamic forest landscape 1975-2007. Timber harvesting was widespread during this period and habitat that previous research has defined as suitable by martens declined by 434,978 ha (32%) as a result of stand-replacing harvests 1975-2007. Declines in probability of occurrence followed two spatiotemporal trends. The majority of loss occurred in the first 16 years of the time series (1975-1991), resulting from salvage logging that occurred in response to the 1973-1985 spruce budworm (Choristoneura fumiferana) outbreak. Rapid declines in probability of occurrence for both male and female martens occurred where large blocks of mature spruce-fir forest were salvaged. Salvage logging also contributed to fragmentation of marten habitat with a 5.6-fold increase in the number of suitable habitat patches 1975-1991. Declines in habitat supply and probability of occurrence continued 1991-2007, coinciding with the broad-scale changes in timber harvesting patterns, ...