• Payer, David C.
  University of Maine Graduate School
  

American marten (Martes americana) have large spatial requirements and specific habitat needs. Presumed habitat requirements of marten form the basis for some forest- management regulations, although few studies have evaluated the effects of timber harvesting on demographic performance. Trapping may confound studies of demography and habitat associations by reducing marten density. Therefore, I investigated habitat selection and demographic characteristics of 163 (87 M, 76 F) radio collared, non juvenile (> 1 yr) marten in an untrapped reserve, a trapped industrial forest, and an untrapped industrial forest in Maine. I also compared structural characteristics of mature, insect-defoliated, and clearcut stands receiving different intensities of marten use.

Areas receiving use by marten had greater tree height, basal area, and snag volume than unused areas. Volume of woody debris and understory foliage density was similar in regenerating and mature stands. Insect-defoliated stands with < 50% overstory canopy closure were intensively used, suggesting that vertical structure provided by large snags can substitute for live trees, and that marten do not require a closed overstory canopy. In managed stands, I recommend maintenance of > 18 m2/ha basal area in live trees and snags, protection of advance regeneration, and retention of woody debris.