Historic Response of Forests to Disturbance; Hydrologic Implications (Invited)

Mountain hydrology is influenced by the composition, structure, and function of forests, which in turn are affected by patterns and types of disturbance, both ecological (insect, disease) and physical (fire, wind, avalanche/landslide, weather/climate). Paleo-historic data provide inferences about the natural roles of disturbance in governing forest condition at landscape scale (e.g., forest die-offs, widespread changes in composition, forest type, or structure), and offer insights for vegetation and hydrological management under conditions of current and future climate change. Millennial (Holocene), centennial, and decadal temporal scales are presented for analysis of forest responses in mountains of western North America. Examples focus on the long-term effects of short-term disturbance, beneficial effects of disturbance on forest health, importance of legacy (sequencing of events), pace of climate variability, topographic control on forest health, lag effects, and interactions of multiple stressors. Historic forest condition and hydrologic relations inferred through dendrochronological analysis are put into current context.