Cooperative Institute for Research in Environmental Sciences

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Alpine Biodiversity & Environmental Change

William D. Bowman
Director, Mountain Research Station
INSTAAR
University of Colorado
spot.colorado.edu/~bowman
www.colorado.edu/mrs

Alpine Biodiversity as a Bellwether of Environmental Change

Biodiversity of mountains is greater than surrounding lowlands, due to altitudinally and topographically driven habitat variation. Human effects on mountain biodiversity tend to be greatest in areas where resource extraction and development occur, but even in relatively pristine alpine areas human influences are present. Biotic changes in the alpine may be reflective of "indirect" anthropogenic environmental effects, including changes in climate, atmospheric chemistry, and transmission of ultraviolet radiation. The relative importance of these environmental changes varies regionally. For example the diversity of plants on the summits of peaks in the Alps has increased in conjunction with a warming trend. Anthropogenic changes in nitrogen cycling are pervasive in developed countries, and their effects may be particularly notable in alpine areas, due to thin, poorly weathered soils, a strong seasonal climate, and low rates of biological activity. The influence of nitrogen deposition is apparent in alpine ecosystems of the Front Range of the Southern Rocky Mountains, where episodic losses of acid neutralizing capacity and elevated NO3- concentrations have recently been recorded. Biotic changes in alpine lakes associated with elevated N loading include changes in the composition and abundance of phytoplankton. Changes in alpine plant species composition have also been recorded, that correspond with species responsiveness to fertilizer additions. Because alpine plant species exert important control over the sensitivity of primary production to changes in climate, and influence spatial variation in rates of nutrient cycling, changes in the composition and abundance of alpine plants associated with environmental change have important feedbacks to ecosystem function.

Book Titles

Baron, J.S., 2002 (ed.) Rocky Mountain Futures: an Ecological Perspective. Island Press

Korner, Ch. and E. Spehn 2002 (eds.). Global Mountain Biodiversity Assessment. Pergamon Press.