PARENT SESSION
Poster Session 37: Forest Ecology.
Thursday, August 5 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Relationships between overstory litterfall and climate in an old-growth temperate rainforest, Olympic Peninsula, Washington.
Edmonds, Robert*,1, McAfee, Stephanie1, Mollett, Lauren1, 1 University of Washington, Seattle, WA, USA
ABSTRACT- There is a great deal of interest in the influence of global climate change on forest ecosystems. Litterfall is an indicator of tree productivity and change in forest ecosystems. We determined annual overstory litterfall in two 0.1 ha plots (with 7 litterfall traps in each) in an old-growth temperate rainforest in the Hoh River Valley in Olympic National Park from 1989 to 1996. Western hemlock and Pacific silver fir are the dominant tree species, but Douglas-fir, western redcedar and Sitka spruce are also present. Litter was sorted into sensescent needles, green needles, reproductive parts, fine woody material, and lichens and mosses. Litter was oven dried. Temperature and precipitation data were obtained from a nearby National Weather Service station in Forks, WA. Total annual litterfall varied from 1517 kg/ha to 4717 kg/ha with senescent needles dominating. Temperature steadily increased during the study period while precipitation was variable. Total litterfall, sensecent litterfall, reproductive litterfall and fine woody litterfall were most strongly positively correlated with precipitation while green litterfall was most strongly positively correlated to temperature. These data have implications with respect to future changes in coastal temperate old-growth relative to global change.
Key words: old-growth forest, litterfall, climate change