Ecology

No Shortcuts in Long-Term Study

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Science  07 May 2004:
Vol. 304, Issue 5672, pp. 797
DOI: 10.1126/science.304.5672.797d

Eutrophication—the effects of nutrient enrichment on ecosystems—has become a familiar phenomenon worldwide. Usually, it is a direct result of the use of fertilizers on agricultural land, and effects are especially noticeable in freshwater ecosystems, often leading to large changes in species diversity and composition. Eutrophication resulting from human activity can also occur indirectly. In the Arctic, for example, a warmer climate is likely to increase permafrost thawing, which in turn may release more nutrients into streams and rivers.

To investigate possible outcomes in Arctic rivers, Slavik et al. experimentally increased the phosphorus (P) loading in the Kuparuk River basin, Alaska, over 16 years. Changes were progressive, with increases in diatom biomass and productivity after 4 years, followed by replacement of diatoms by mosses after 8 years, with further effects on the entire habitat structure and the composition of insect communities. Thus, some of the consequences of nutrient enrichment are delayed and unpredictable and can only be understood and evaluated through long-term study. — AMS

Ecology 85, 939 (2004).

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