ISSN:
1573-5117
Keywords:
nitrogen
;
phosphorus
;
chlorophyll
;
organic matter
;
mountain lakes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Concentrations of total phosphorus (TP), inorganic and organic nitrogen, organic matter, and chlorophyll-a were studied in ten mountain lakes at various stages of acidification, trophy, and type of watershed during each July and October from 1987 to 1990. Concentrations of TP and total organic matter were higher in July than in October. Concentrations of NH44 +-N decreased and NO3 −-N increased from July to October. The relative composition of total nitrogen (TN) and its concentration were strongly dependent on the type of watershed: the lowest TN concentrations were observed in lakes with forested watersheds, increasing above the timberline and reaching maximum values in acidified lakes with rocky watersheds. In the pool of TN, nitrate was most important in lakes above the timberline (70–86% of TN), and organic nitrogen in forest lakes (〉 90% of TN). Lakes with rocky watersheds were characterized by high ratios of TN:TP (〉 250 by mass). The concentration of chlorophyll-a varied widely, from 0.01 to 22.6 µg l−1, without any consistent change between July and October, and were P limited.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00020970