Abstract: The Kraenepoel, a shallow, oligotrophic, fresh water lake (app. 22 ha), which was originally a peat extraction site, was used as a fish culture pond during several centuries. In the last few decades, the area has been increasingly threatened by a continuing eutrophication, which seriously affected the nutrient-poor and mineral nature of the habitat. The main objectives of a European LIFE-project were the restoration, preservation and protection of the Kraenepoel as an oligotrophic fresh water habitat with an appropriate fish population. As a restoration measure, the lake was drained and highly organic sediments were removed. Results from resembling studies in the Netherlands illustrate the successful recovery of rare and even formerly disappeared plant species. Little is however known about the effects of such measures on the macroinvertebrate community, or the fauna on the whole. Therefore an inventory of this community was drawn up before draining the lake (spring and summer 1999; T0). Although the effect of eutrophication is clearly reflected by the macroinvertebrate species composition, still, the quality of this lake can be regarded as high in comparison with similar lakes in Flanders. After partial restoration of the lake and refill by ground water and rainwater only (winter 2000-2001; T1), a follow-up of its recovering community is ongoing. The first results of samples taken in late winter (February-March 2001) show an expected, serious decline inabundance numbers and species diversity compared to T0-results. Sampling in spring 2001 however shows a steady but apparent recovery of species found in T0. After 9 months of recovery, abundance numbers have reached the T0 state again and have even exceeded these numbers. Besides, the taxonomic diversity is still increasing. Furthermore, shifts are being noted in the species distribution among the sampling sites. It can be expected that future results will show a further recovery of the diversity. Whether and when the final stabilization of the lake will result in a successful restoration of a more unique, nutrient-poor environment is unknown. So far no signs are found indicating a shift towards a new macroinvertebrate community.
sediments, macroinvertebrates, freshwater, ecology, biotic index, BSI, macrozoobenthos, triad, biological quality assessment, biotic sediment index, Ecology, Limnology and hydrobiology, Streams , running waters, shallow lakes, Kraenepoel, Biological control, Bioinformatics and databases, Habitat management, restoration, Systematics and taxonomy, Ponds and lakes , standing waters, The effect of Biodiversity on Ecosystem Functioning, Origins, Maintenance and Change of Biodiversity, Systematics, Inventorying and Classification, Monitoring of Biodiversity, Inland Water Biodiversity, Belgium, Flanders, Aalter, Metazoa, Invertebrata, Insecta, Diptera, Chironomus, Chironomidae, Hemiptera, Coleoptera, Trichoptera
|Laboratory of Environmental Toxicology and Aquatic Ecology||unknown|
|Heylen, S. and N. De Pauw (2000). Macroinvertebrate research of the Kraenepoel at Aalter. Study by order of: Ministry of the Flemish Community, Department Environment and Infrastructure, Administration Environment, Nature, Land and Water management, Division Nature. Ghent, Belgium, Ghent University, Department Applied Ecology and Environmental Biology, Laboratory of Environmental Toxicology and Aquatic Ecology: 41 p.||author|
created:2011-12-14 14:18:59 UTC, source:biodiv