Het Zuideindigerwiede, een uniek verlandingsgebied
Gorteria Dutch Botanical Archives , Volume 3 - Issue 11 p. 165- 181
The Zuideindigerwiede is a lake in the north-western part of the province of Overijssel (The Netherlands). The eastern part shows a succession of nymphaeids and helophytes. This series is exposed to the prevailing winds. The western part shows a succession of stratiotids, hydrocharids and pleustophytes and of ‘sapropelophytes’. In both cases there is an increase in vegetational structure, especially in the number of growth forms. Secundarily, a zonation of Ceratophyllum demersum may establish itself before the Stratiotes-zonation and a zonation of Calla palustris develops as a fringe around the floating islands. When ‘isolation’ of small masses of water occurs, a vegetation rich in Utricularia vulgaris may develop in places where the water is shallow and Stratiotes has died off. The second series proceeds more rapidly than the first, the sapropelium being deposited along the western shoreline by an undercurrent, caused by the dash of waves against the opposite bank. Special attention is focussed on several interesting species, such as Azolla caroliniana and Calla palustris. Generally the succession series exhibits the same trends in other lakes in the Netherlands. In more extreme situations only a part of the series is developed, and in the most extreme case only the elodeïd-phases occur. The submerged stages of nymphaeids, helophytes and stratiotids show ’transitions’ to elodeids in an ecological sense.
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