Overstory litter inputs and nutrient returns in an old-growth temperate forest ecosystem, Olympic National Park, Washington

• Published in: Canadian journal of forest research Vol. 32; no. 4; pp. 742 - 750
• Main Authors: Edmonds, R.L, Murray, G.L.D
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.04.2002; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; calcium; canopy; conifer needles; Ecosystems; Forest ecosystems; forest litter; Forests; Fundamental and applied biological sciences. Psychology; geographical variation; lichens; magnesium; manganese; National parks; nitrogen; nutrient availability; Nutrients; phosphorus; potassium; Rainforests; senescence; shade; sodium; Synecology; Temperate forests; Terrestrial ecosystems; Trees; Tsuga heterophylla; understory; Waterfalls; watersheds; wood; Washington; United States; North America; America; United States > US; Terrestrial environment; Litter; Ecology; Overstorey; Forest soil; Biogeochemical cycle; Inorganic element; Temperate zone; National park; Biogeochemistry; Regional study; Ecosystem; Softwood forest tree; Forestry; Gymnospermae; Plant origin; Coniferales; Spermatophyta; Fall; Tsuga heterophylla; TEMPERATE FORESTS; Primary forest
• ISSN: 0045-5067; 1208-6037
• DOI: 10.1139/x01-227

Overstory litterfall rates and nutrient returns were determined in an old-growth temperate rainforest watershed in the Hoh River valley, Olympic National Park, Washington. Litter was sorted into green needles, senescent needles, fine wood, reproductive, and miscellaneous litter (mostly arboreal lichens and mosses). Understory and coarse woody debris inputs were not determined. Total annual overstory litterfall averaged 3594 kg(.)ha-1 and varied among the six plant communities in the watershed. There was a trend for litterfall to be higher in the upper watershed; elevations ranged from 180 to 850 m. Needles provided the greatest amount of litterfall (60%) with woody litter and other material averaging 18 and 22%, respectively. Highest senescent needle litterfall occurred from July to October, but highest woody litterfall was from January to April. Green needles provided only 3% of annual needle litterfall. Green and senescent needle litterfall were related to western hemlock (Tsuga heterophylla (Raf.) Sarg.) basal area, suggesting that this shade-tolerant species was the greatest contributor to needle litterfall. The following quantities (kg(.)ha-1) of nutrients were returned to the forest floor annually: Ca, 26.8; N, 24.6; K, 4.0; Mg, 3.0; P, 2.9; Mn, 1.7; and Na, 1.2.