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Large woody debris in a headwater stream: long-term legacies of forest disturbance

Author(s): J. Bruce Wallace, Jackson R. Webster, Sue L. Eggert, Judy L. Meyer, Edward R. Siler
Year Published: 2001

We excluded litter (leaves and wood) inputs to an Appalachian headwater stream for 5 years. Leaves disappeared from the streambed very rapidly (<1 year) following litter exclusion, however, a large residual mass of woody debris remained. After excluding inputs of leaf litter and wood to the stream for 3 years we removed all small wood (<10 cm diameter) from the stream. There was close agreement (within 10%) between estimates of mass of small woody debris made using line intersect methods and that made by direct removal. Two years later, we removed all large woody debris (LWD = >10 cm di- ameter) from the wetted perimeter of the stream. Five annual estimates of LWD mass made with line intersect methods exceeded those of complete removal by a factor of about 2×, although total wood removed was within the 95% confidence interval of that estimated by the line intersect method. Spe- cies of wood removed from the stream displayed weak similarity (percent similarity = 45 to 49%) with recent (1993 and 1972) measures of basal area of tree species in the surrounding forest, but stronger similarity (65%) with tree species measured in 1934. About 37% of the LWD removed consisted of American chestnut, Castanea dentata, (~24%) and black locust, Robinia pseudoacacia, (~14%), which currently represent < 1.5% of the basal area of the surrounding forest. LWD in the stream reflects large inputs of chestnut following the chestnut blight in the1930s and inputs of early successional species such as black locust following extensive timber harvesting in the early 1920s. These earlier disturban- ces to the forest were important sources of LWD that remain in the stream today. Thus, the structure and function of present day streams are influenced by forest disturbances that occurred over six decades ago.

Citation: Wallace JB, WebsterJR, Eggert SL, Meyer JL, and Siler ER. 2001. Large woody debris in a headwater stream: long-term legacies of forest disturbance. International Review of Hydrobiology 86 (4-5): 501-513. https://doi.org/10.1002/1522-2632(200107)86:4/5<501::AID-IROH501>3.0.CO;2-8
Topic(s): Fire Effects, Ecological - Second Order, Soils, Fuels
Ecosystem(s): None
Document Type: Book or Chapter or Journal Article
NRFSN number: 18689
Record updated: Dec 3, 2018