Nitrogen fluxes in a high elevation colorado rocky mountain basin

✍ Scribed by JILL S. BARON; DONALD H. CAMPBELL

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 526 KB
• Volume: 11
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(199706)11:7<783::aid-hyp519>3.0.co;2-u

✦ Synopsis

Measured, calculated and simulated values were combined to develop an annual nitrogen budget for Loch Vale Watershed (LVWS) in the Colorado Front Range. Nine-year average wet nitrogen deposition values were 1 . 6 s 0Á36 kg NO 3 -N ha À1 , and 1 . 0 s 0Á3 kg NH 4 -N ha À1 . Assuming dry nitrogen deposition to be half that of measured wet deposition, this high elevation watershed receives 3Á9 kg N ha À1 . Although deposition values ¯uctuated with precipitation, measured stream nitrogen outputs were less variable. Of the total N input to the watershed (3Á9 kg N ha À1 wet plus dry deposition), 49% of the total N input was immobilized. Stream losses were 2Á0 kg N ha À1 (1125 kg measured dissolved inorganic N in 1992, 1±2 kg calculated dissolved organic N, plus an average of 203 kg algal N from the entire 660 ha watershed). Tundra and aquatic algae were the largest reservoirs for incoming N, at approximately 18% and 15% of the total 2574 kg N deposition, respectively. Rocky areas and forest stored the remaining 11% and 5%, respectively. Fully 80% of N losses from the watershed came from the 68% of LVWS that is alpine.