Potential large woody debris sources in riparian buffers after harvesting in Oregon, U.S.A

• Published in: Forest ecology and management Vol. 112; no. 1; pp. 67 - 77
• Main Authors: Hairston-Strang, Anne B., Adams, Paul W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.12.1998; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; diameter; fish; forest litter; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forest practices; Forestry; Fundamental and applied biological sciences. Psychology; habitats; Large organic debris; length; logging; Pacific Northwest; prediction; Riparian areas; riparian forests; Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Synecology; Terrestrial ecosystems; wind damage; Windthrow; Oregon; United States; North America; America; Large organic debris; Forest practices; Windthrow; Riparian areas; Pacific Northwest; Vertebrata; Organic matter; Silviculture; Animal plant relation; Riparian; Pisces; Harvesting; Silvicultural systems; Habitat; Debris
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(98)00311-9

Twenty-one riparian buffers on private lands in Oregon were measured after harvest using the 1994 revised Oregon Forest Practices Rules to determine their ability to contribute large woody debris (LWD) to streams for fish habitat. On average, 51% of the trees retained in riparian buffers after harvest currently would be capable of adding debris at least 20 cm diameter and 1.5 m length to the channel. Assuming 30% of trees are windthrown over 10 years and that trees fall in random directions, the riparian buffers would be expected to add an average of 0.6 trees per 100 m (1.9 trees per 1000 ft) of stream as LWD over 10 years. Analysis showed significantly greater LWD inputs ( p<0.05) when the likelihood of more frequent windthrow on riparian terraces and of trees tending to fall downhill on steep slopes are considered. On the sites investigated and with the information available, considering tree lean did not significantly increase expected LWD delivery. More data on windthrow rates and direction are needed to confirm the analyses. Depending on longevity, the expected frequency of LWD pieces could remain within ranges observed in undisturbed stands.