Logging and boreal ground-beetle assemblages on two continents: implications for conservation.

Abstract

We studied the effects of clear-cutting on ground-beetle (Coleoptera. Carabidae) assemblages in Canadian and Finnish boreal forest by comparing pitfall samples from young. regenerating forests with those from natural. primary forests. More than half (15) of the 26 genera. but only four of the 108 species. were shared between the two continents. On both continents. carabid abundance was highest in the youngest regenerating sites (1-10 years since cutting) and in certain types of primary forest. Species richness and diversity was higher in the regenerating sites than in the primary forest on both continents. Three types of numerical responses of species to logging were distinguished: (I ) species of open habitat appeared and/or increased in abundance; (2) forest generalists were not dramatically affected and occurred in all or most forest types; and (3) primary forest specialists disappeared after forest cutting. Most species in each of the three groups were taxonomically closely related on the two continents. Our results suggest that biotic diversity can be maintained throughout the boreal forest by a general management approach that maximizes habitat diversity on the regional scale. However. knowledge of local conditions and fauna will be essential to conserve specific assemblages of Iiller­ dwelling invertebrates. K.J. Oaslllll. T.R. New and M.l Samways: Pe,speClives Oil 'lisee/ COIISt!TVtI/i,, @ 1'193 Itllcn:cpll.ld.I'O nllx 716. Anduver. Hampshire SI'J() IYO. UK -