Effects of Hemlock Mortality on Streams in the Southern Appalachian Mountains

Autor: B. R. Niederlehner, K. Morkeski, Jackson R. Webster, Ernest F. Benfield, C.A. Wojculewski, Katherine J. Elliott
Rok vydání: 2012
Předmět:
Zdroj: The American Midland Naturalist. 168:112-131
ISSN: 1938-4238
0003-0031
DOI: 10.1674/0003-0031-168.1.112
Popis: The death of eastern hemlock (Tsuga canadensis) trees in response to infestation by the introduced hemlock woolly adelgid (Adelges tsugae) may affect ecosystem processes and structure of streams. Prior to hemlock mortality, we documented the conditions of eight small streams and their associated riparian forests within the Appalachian Mountains of North Carolina, U.S.A. Hemlock was the dominant tree species on all riparian sites and was always associated with rhododendron (Rhododendron maximum). Significant trends of increasing canopy openness, increasing light to the streams and increasing annual temperature range were observed. Contributions of hemlock to litterfall, in-stream wood, and benthic organic matter were important at the beginning of the study, suggesting that the loss of hemlock may significantly modify the trophic dynamics and physical structure of southern Appalachian streams. Increased growth of rhododendron in response to hemlock mortality may compensate for the trophic influence...
Databáze: OpenAIRE