Abstract
The accretion rate of sediments in a lake ecosystem is an index of its rate of aging. In shallow eutrophic Lake Wingra, sedimentation is coupled to a positive feedback system involving littoral vegetation, the phytoplankton, and sediments near enough to the water surface for colonization by macrophytes. Rooted plants enrich the water with nutrients and organic matter above the normal resuspension of sediments, thereby stimulating pelagic production and sedimentation that eventually produce more surface area colonizable by macrophytes. Analysis of a budget for colonizable surface area shows that relatively large changes in the rate of colonizable sediment accrual result from small changes in internal loading from sediments and littoral plants, the efficiency of decomposition, and the rate of sedimentation. On the other hand, the rate of accretion of colonizable sediment is relatively insensitive to changes in the influx of phosphorus and dry matter to the lake from the watershed. Internal mechanisms of enrichment such as those described here accelerate the eutrophication of lakes. This tendency toward autogenic eutrophication is not consistent with the hypotheses of lake development proposed by Odum (1969) and Margalef (1975). Evidently the direction and rate of lake succession depend upon basin morphometry and the abundance of littoral vegetation as well as inputs from the watershed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.