Trends in precipitation and stream chemistry in a pristine old-growth forest watershed, Olympic National Park, Washington

Abstract

Time trends in precipitation and stream chemistry in a pristine old-growth forest watershed and seasonal patterns in precipitation and stream chemistry were determined at the Olympic National Park, Washington. Chemistry of precipitation was strongly dominated by oceanic influences with Na and Cl being the dominant ions. The chemistry of the stream was influenced by bedrock weathering and was dominated by Ca, HCO3 and SO4. The pH of precipitation ranged from 4.3 to 7.1, while the stream pH ranged from 5.5 to 9.0. There were no significant seasonal patterns in the precipitation.