0000000000303676
AUTHOR
Ramesh D. Gulati
A multivariate analysis of phytoplankton and food web changes in a shallow biomanipulated lake
1. Phytoplankton dynamics, food chain changes and resilience in Lake Zwemlust, a shallow lake in The Netherlands, are described for the period 1986-94. 2. After biomanipulation in 1987, the lake moved through two alternative states, while the external nutrient loadings were maintained. A clear-water phase, mostly dominated by macrophytes, persisted from 1987 to 1991, and a rather turbid state, dominated by algae, occurred in the summers of 1992-94, after several consecutive and sustained perturbations affecting different parts of the food web in the lake. These two periods were characterized by different community structures. 3. The phytoplankton assemblage gradually changed in a pattern th…
Biological and Ecological Features, Trophic Structure and Energy Flow in Meromictic Lakes
Case studies and typical examples for meromictic lakes are used to provide a review of the biology and ecology of these ecosystems. Water column in meromictic lakes is not entirely mixed. These lakes are chemically and/or thermally stratified for several years and have several specific ecological features. The chemocline —the habitat created between the mixolimnion on top and monimolimnion below—is characterised by the existence of complex bacterial communities, autotrophic and heterotrophic protists and metazooplankton, commonly dominated by rotifers , high rates of oxygenic and anoxygenic photosynthesis and some biogeochemical processes . In these lakes, the sulphur, carbon and nitrogen c…