NORTHERN FORESTRY AND CARABIDS - THE CASE FOR CONCERN ABOUT OLD-GROWTH SPECIES

Two studies in western Canada focus on whether carabid species special ize in use of old-growth forest habitats. In montane lodgepole pine (P inus contorta Douglas var. latifolia Engelm.) forest, Calathus advena Lee., Carabus chamissonis Fish., Leistus ferruginosus Mnh., Nebria int ermedia V. D., Platynus decentis Say, Pterostichus brevicornis Kby., P terostichus riparius Dej., Scaphinotus marginatus Fisch. and Trechus c halybeus Dej. are common in post-rotation age forest with no history o f harvesting, but scarce in or absent from regenerating sites, even 27 years after harvest. Residual populations of old-growth specialists i n uncut fragments are exposed to increased contact with habitat, gener alists and open-habitat specialists from surrounding cut-overs and reg enerating forests. Populations of several species of old-growth specia lists in lodgepole pine live also in younger, fire-origin stands in bo real aspen (Populus tremuloides Michaux.) stands of the ''mixedwood'' zone. We hypothesize that they have recolonized from the large surroun ding tracts of unburned residual forest remaining after fire. Thus, la ndscape-scale effects, resulting in changes in regional population siz e, may alter the probability of species retention in old-growth fragme nts, and of the recolonization of cut-blocks by particular species cha racteristic of old-growth.