Multi-century, Multi-scale Analysis of Fire Regimes and Climatic Variability in the Mediterranean-Climate Areas of California and Southwestern Oregon.
Fire is a key process that shapes forest ecosystem structure and function on the Mediterranean-Climate areas of California and southwestern Oregon. The mild-wet winter/warm-dry summer climate predisposes forests to conditions that can burn annually. However, climate variability and climatic change are known to influence fire frequency and extent over a range of temporal and spatial scales. The goal of this project is to identify the effects of intra-annual and intra-decadal climate variation and multi-decadal and multi-century climatic change influence montane forest fire regimes over a range of spatial scales along a north-south transect that extends over 5° of latitude in western California and southwestern Oregon. Specific objectives are to: 1) determine how 20th century fire-climate interactions vary along the transect; 2) determine how the dominant modes of climatic variability (ENSO, PNA, PDO) are related to spatial and temporal variation in 20th century fires; 3) determine how atmospheric circulation patterns for high and low extremes of the modes of climatic variability are related to recent (post 1950) fires; 4) determine long-term spatial and temporal patterns of temperature and precipitation patterns using tree rings and relate these to long-term reconstructions of the dominant modes (ENSO, PDA, PDO)of circulation; and 5) determine how multi-century records of fire occurrence, climate variability, climatic change, and dominant circulation (ENSO, PDA, PDO) modes vary across spatial scales along the transect.