Productivity and Carrying Capacity of a Subarctic Sheep Winter Range

Abstract

altitude and aspect, as well as among years, according to rainfall during the growing season. Extremes were 29.1 g.m-2 and 120.1 g.m- . Over the IO-year assessment period, the vegetative composition did not tion is functioning. ABSTRACT. Estimates of range composition and net primary productivity for a IO-year period are presented for the semi-arid grasslands of Sheep Mountain, Kluane National Park, Yukon, the winter range of a Dall’s sheep (Ovis dalfi dalli) population. Estimates varied among plots, depding on about 200 sheep was within the carrying capacity of the range. A 40% utilization rate of the winter range forage can evidently be sustained and pro- vides a stocking rate of about 1.9 sheep-monthS.ha-I. A significant correlation is demonstrated between forage production of the winter survival the following winter, and lamb production the following change nor was there a grazing-related reduction in productivity. Winter range use by range, lamb spring. This correlation indicates that a form of self-regulation of the sheep popula-