EFFECTS OF FOREST SUCCESSION AFTER FIRE IN MOOSE WINTERING HABITATS ON THE KENAI PENINSULA, ALASKA

Abstract

Estimates of moose (Alces alces) density during winter in early seral forests created by human-caused wildfires and in older successional forests on the northern Kenai Peninsula were obtained using data from standardized aerial surveys conducted from 1964-1990. Wintering moose densities in the study area were highest within areas burned by wildfires in 1947 and 1969, reaching peaks of 3.6-4.3 moose/km². Density estimates for the 1947 burn were available 17-43 years post-fire. The relationship between moose density and forest age in the 1947 burn from 1964-1990 was highly significant (P < 0.01, R² = 0.68), and density declined at a rate of approximately 9 percent per year during this period. Highest densities, ranging from 2.0-3.6 moose/km², were recorded 17-26 years post-fire (1964-1973). Winter moose density in the 1947 burn and the area's total moose population then declined abruptly. Favorable habitat created by the 1969 wild fire resulted in a major increase in total population by 1982, although wintering densities in the 1947 burn remained low. Moose density estimates in the 1969 burn following this increase were high and remained relatively constant 13-21 years post-fire (1982-1990), ranging from 3.6-4.4 moose/km². In older successional forests, wintering moose density was low throughout the study., ranging from 0.1-0.8 moose/km². Forest succession in the 1969 burn will ultimately result in habitat capable of supporting wintering moose densities similar to those currently found in mid-successional and older forests. We predict the area's moose population will decline in the absence of early seral forests.