The Modern Landscape of the Olympic Peninsula

Abstract

The natural environment of the Olympic Peninsula is reviewed with an emphasis on climatic gradients and associated patterns in forest communities and natural disturbance regimes. The regional climate is described with respect to the broadscale circulation features and locally important topographic effects. Analyses of weather station data reveal important trends in temperature, while snow survey and glacier monitoring reveal decades-long decline in snowpack. The summer streamflow of unregulated rivers is shown to have a strong link to variation in snowpack. The seven major vegetation zones of the peninsula are described and controls of species abundance among vegetation zones are discussed with respect to species traits and climatic gradients. The natural disturbance regimes of the peninsula are summarized. Fire history data from tree-ring records and fire regime statistics from historical records reveal the pronounced gradient of fire across the peninsula and the episodic pattern of large fire events. Wind, insect, geomorphic, and intense herbivory are also briefly reviewed.