Effects of Timber Harvesting on Marten in Maine

Abstract

The influence of timber harvesting on marten (M. a. americana) was studied in spruce-fir-hardwood forests in the Moosehead Lake Region, Maine, during 1974-1977. Partial harvesting and commercial clear-cutting were examined. In the partially harvested forest, basal area was reduced by about 40%. In the commercial clear-cut forest, 50% of the forest was clear-cut and 25% was cut selectively. Density of adult, resident marten averaged 1.2/km2 in the undisturbed and partially harvested forests, but was 0.4/km2 in the commercial clear-cut forest. Home range lengths were longest in the commercial clear-cut forest. In undisturbed forests, marten preferred softwood-dominated mixed stands. In the partially harvested forest, tracks were found in all cover types in proportion to the occurrence of the cover types. Marten rarely used the 0-15 yr old clear-cut areas, but the associated lightly cut hardwood stands and islands of uncut softwoods were heavily used. Of the more common foods eaten by marten, meadow voles (Microtus pennsylvanicus), ground nesting birds and raspberries (Rubus idaeus) were more abundant in the harvested forests, while red-backed vole (Clethrionomys gapperi) numbers were not affected by logging. Harvesting methods that maintain a residual stand of 20-25 m2/ha basal area in pole and larger trees provide adequate habitat for marten. Clear-cuts up to 15 yr old are poor marten habitat.