Document: LIS-3-9-2

1000 years of climate change and ecological response in Western montane forests.

GRAUMLICH, L.J.*

Montana State University, Bozeman MT 59717 USA ¹

Abstract:
Mountains of western North America provide strong evidence for climatic variability at time scales of decades to millennia from sources such as tree rings, glacial ice, and sediments. On decadal scales, climatic oscillations driven by sea surface temperatures (ENSO, Pacific decadal oscillation) are manifest as regionally scaled droughts. On century to millennia time scales, temperature variations exceed the range of 20th century observational data. In this paper, I evaluate the evidence for climatic impacts on forest ecosystems, focusing on new millennial-length records of climatic change and forest response for the Greater Yellowstone Ecosystem. Specifically, I address the theme of the symposium ("Detecting Change and its Consequences") by focusing on two questions: (1) Are current trends in climate and tree growth unprecedented with respect to long-term patterns of variability? and (2) What do past patterns of climatic change and forest response indicate about prospects for the 21st century?.

Keywords: climate change, Greater Yellowstone Ecosystem, forest dynamics

This abstract is being presented at: 8:30 AM in session:
Symposium # 2: Stressors in Western Mountain Ecosystems: Detecting Change and Its Consequences.