WATER CHEMISTRY OF ROCKY-MOUNTAIN FRONT RANGE AQUATIC ECOSYSTEMS

A study of the water chemistry of Colorado Rocky Mountain Front Range alpine/subalpine lakes and streams in wilderness ecosystems was conduc ted during the summer of 1995 by the USDA Forest Service Arapaho and R oosevelt National Forests and Rocky Mountain Forest and Range Experime nt Station, and the University of Colorado Institute of Alpine and Arc tic Research. Data were collected to examine the water chemistry of Fr ont Range high-elevation lakes and their sensitivity to atmospheric de position, particularly nitrogen saturation. Water chemistry data from synoptic surveys of high-elevation lakes in wilderness areas of other National Forests in Colorado are also included in this report. Because of the extent, uniqueness, and potential value of the data collected, the entire water chemistry data base including over 265 samples from more than 130 lakes and streams is presented. Preliminary data examina tion indicates that many lakes have detectible nitrate concentrations, nitrate concentrations are higher early in the season and decrease as the season progresses, and inlets often have higher nitrate concentra tions than outlets. Detailed data analysis and interpretation, its rel ationship to landscape characteristics, and tile implications for ecos ystem response and management will be presented by the authors in subs equent manuscripts in preparation.