Long-term responses of the Kuparuk River ecosystem to phosphorus fertilization

• Main Authors: K. Slavik, B. J. Peterson, L. A. Deegan, W. B. Bowden, A. E. Hershey, J. E. Hobbie
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: Arctic; north slope; Tundra; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.583.7274; http://tiee.ecoed.net/vol/v3/issues/data_sets/arc/pdf/Ecology(Slavik).pdf

Abstract. A long-term stream fertilization experiment was performed to evaluate the potential eutrophication of an arctic stream ecosystem. During 16 years of summer phos-phorus (H3PO4) fertilization, we observed a dramatic change in the community structure of the Kuparuk River on the North Slope of Alaska. A positive response to fertilization was observed at all trophic levels with increases in epilithic algal stocks, some insect densities, and fish growth rates. After approximately eight years of P fertilization, bryo-phytes (mosses) replaced epilithic diatoms as the dominant primary producers in the Ku-paruk River. The moss impacted NH41 uptake rates, benthic gross primary production, habitat structure, and insect abundance and species composition. This study documents the long-term changes in an arctic tundra stream in response to nutrient enrichment. Predicting stream ecosystem responses to chronic perturbation requires long-term observation and experiments. Key words: arctic stream; bryophytes; community structure; ecosystem response; grayling; in-sects; Kuparuk River, Alaska (USA); nutrient enrichment; phosphorus fertilization; stream fertilization.