MOOSE RANGE UNDER PRESETTLEMENT FIRE CYCLES AND FOREST MANAGEMENT REGIMES IN THE BOREAL FOREST OF WESTERN CANADA

Abstract

To evaluate the impact of large-scale forest management on moose (Alces alces), yield of deciduous woody browse was modelled for fire cycles of 38, 50, 75 and 100 years (the range of historic fire cycles in the closed boreal forest) on a hypothetical 50,000 km2 area of northwestern Canadian boreal forest. Browse yield was also estimated for the Alberta forest of the 1980’s and for managed forest alternatives during 60 and-80-year rotations accompanied by (a) a reserve of 5% for old forest and (b) a separate group of stands on a 250-year rotation sufficiently large to keep 5% > 150 years old. low carrying capacities for moose were estimated for the long (250 year) rotation and for forests in Alberta as they were in the 1980’s. Estimated moose carrying capacities in the managed rotations were in the same range as those in the presettlement forest fire cycles, suggesting that future forest management in the region should be adequate to sustain moose populations at historic levels. Uncontrolled access to manage forests, and/or stand conversion to conifers with intensive control of deciduous vegetation could, however, limit moose numbers.