Von Trebra et al. (1998) concluded that shelterwood. harvesting of sub-bore
al spruce forest did not negatively affect small mammal populations. Howeve
r apparent problems with their experimental design leave us without a clear
understanding of small mammal responses to forestry practices. I offer sta
tistical and biological rationales as to why their experimental design was
likely inappropriate to test the hypothesis that "a shelterwood silvicultur
al system would reduce small mammal populations" (Von Trebra et al. 1998:63
1). My objections emphasize issues of ecological scale, which suggests smal
l mammal population results reported in their paper may not have reflected
the habitat condition of individual experimental blocks, much less treatmen
t units. Finally, I discuss implications to forest management, notably the
conservation of sensitive species, of inferring conclusions and offering ma
nagement recommendations from dubious results.