A Comparison of Fire Regimes and Stand Dynamics in Whitebark Pine (Pinus albicaulis) Communities in the Greater Yellowstone Ecosystem

Abstract

Whitebark pine (Pinus albicaulis) is a keystone species of upper subalpine ecosystems (Tomback et al. 2001), and is especially important in the high-elevation ecosystems of the northern Rocky Mountains (Arno and Hoff 1989). Its seeds are an essential food source for the endangered grizzly bear (Ursus arctos horribilis), particularly in the autumn, prior to winter denning (Mattson and Jonkel 1990, Mattson and Reinhart 1990, Mattson et al. 1992). In the Greater Yellowstone Ecosystem (GYE), biologists have concluded that the fate of grizzlies is intrinsically linked to the health of the whitebark pine communities found in and around Yellowstone National Park (YNP) (Mattson and Merrill 2002). Over the past century, however, whitebark pine has severely declined throughout much of its range as a result of an introduced fungus, white pine blister rust ( Cronartium ribicola) (Hoff and Hagle 1 990, Smith and Hoffman 2000, McDonald and Hoff 2001 ), native pine beetle (Dendroctonus ponderosae) infestations (Bartos and Gibson 1990, Kendall and Keane 2001 ), and, perhaps in some locations, successional replacement related to fire exclusion and fire suppression (Arno 2001).