The Role of Dendrochronology in Understanding the Modern Decline of Whitebark Pine in Grand Teton National Park, Wyoming

Abstract

Whitebark pine (Pinus albicaulis) is the only pine keystone species found in North America. Although it is considered a keystone species in high elevation ecosystems in the northern Rockies, it occupies a relatively restricted range and its future is uncertain. In modern times, it has experienced a significant decline in population due to pine beetle infestations, blister rust infections, fire suppression, and climate change. Despite the knowledge that the species is severely threatened, little is known about its paleoecology. More specifically, much remains unknown about how the distribution and stability of whitebark pine were affected by past climate change. The purpose of this study is to determine in great temporal and spatial detail the demographics of the current stand of whitebark pine trees in the watershed surrounding an unnamed, high-altitude pond (known informally as Whitebark Pine Moraine Pond) located approximately 3.06 miles NW of Jenny Lake in Grand Teton National Park (GTNP). The main objectives of this study are: 1.) To obtain the precise GPS locations of the current stand of whitebark pine trees in the watershed to generate a GIS map detailing their locations. 2.) To obtain increment cores of a subset of the trees in the watershed to estimate age and date of establishment for the current stand of whitebark pines, with particular attention to fire history. 3.) To analyze ring widths from core samples to identify climatic indicators that may influence the regeneration and survival of whitebark pine.