Research article2000Peer reviewed
Colonization and development of stream communities across a 200-year gradient in Glacier Bay National Park, Alaska, USA
Milner, AM; Knudsen, EE; Soiseth, C; Robertson, AL; Schell, D; Phillips, IT; Magnusson, K
Abstract
In May 1997, physical and biological variables were studied in 16 streams of different ages and contrasting stages of development following glacial recession in Glacier Bay National Park, southeast Alaska. The number of microcrustacean and macroinvertebrate taxa and juvenile fish abundance and diversity were significantly greater in older streams. Microcrustacean diversity was related to the amount of instream wood and percent pool habitat, while the number of macroinvertebrate taxa was related to bed stability, amount of instream wood, and percent pool habitat. The percent contribution of Ephemeroptera to stream benthic communities increased significantly with stream age and the amount of coarse benthic organic matter. Juvenile Dolly Varden (Salvelinus malma) were dominant in the younger streams, but juvenile coho salmon (Oncorhynchus kisutch) abundance was greater in older streams associated with increased pool habitat. Upstream lakes significantly influenced channel stability, percent Chironomidae, total macroinvertebrate and meiofaunal abundance, and percent fish cover. Stable isotope analyses indicated nitrogen enrichment from marine sources in macroinvertebrates and juvenile fish in older streams with established salmon runs. The findings are encapsulated in a conceptual summary of stream development that proposes stream assemblages to be determined by direct interactions with the terrestrial, marine, and lake ecosystems.
Published in
Canadian Journal of Fisheries and Aquatic Sciences
2000, Volume: 57, number: 11, pages: 2319-2335 Publisher: NATL RESEARCH COUNCIL CANADA
UKÄ Subject classification
Ecology
Publication identifier
DOI: https://doi.org/10.1139/cjfas-57-11-2319
Permanent link to this page (URI)
https://res.slu.se/id/publ/83765