Small mammal responses to clear-cut logging in boreal mixedwoods of northeastern Ontario: Forest age and disturbance type effects

During the summers of 1998 and 1999, small mammal communities in 18 post-harvest (clear-cut) and 17 post-fire boreal mixedwood stands (30--70 years old) in northeastern Ontario were sampled using pitfall and snap traps. Comparisons of habitat features indicated that post-harvest stands had reduced structural complexity compared to post-fire stands and tended to be more deciduous dominated. Disturbance history did not significantly affect species diversity, but most small mammals were found in greater abundances in fire-origin stands. Moreover, analyses showed that logging-induced variation in habitat structure was correlated with variation in the abundances of several small mammal species. Structural complexity appears to develop more slowly in post-harvest stands than in post-fire stands, limiting species abundances within harvest-origin stands as they mature. Silvicultural methods should therefore focus on residual stand structures, which may influence structural complexity and the availability of small mammal habitat during forest development after logging.