Production of epipelic algae before and during lake fertilization in a subarctic lake

• Published in: Ecography
• Main Author: Björk‐Ramberg, Susanna
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1983
• Subjects: Ecology, Evolution, Behavior and Systematics; Northern Sweden; Subarctic
• Online Access: http://dx.doi.org/10.1111/j.1600-0587.1983.tb01229.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.1983.tb01229.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.1983.tb01229.x

Epipelic production was studied over three years in Lake Gunillajaure, a small, subarctic lake in northern Sweden. In 1977 the lake was in its natural state and in 1978 and 1979 it was continuously fertilized with phosphorus and nitrogen. The fertilizations in 1978 and 1979 did not increase the annual epipelic production measured with 14 C technique. Also the seasonal production pattern was the same during the three years. The variation in production with depth was similar all three years with mean values of 85 mg C m ‐2 d ‐1 at 2 m and 1 mg C m ‐2 d ‐1 at 11 m. Light penetration and water temperature were found to be the most important environmental factors affecting epipelic production. A long turnover time, between I months and 14 yr at different depths, of the probably well adapted epipelic community is suggested to be an explanation to the absence of a response to the fertilization.