Biotoopverschuiving van de Gevlekte witsnuitlibel (Leucorrhinia pectoralis) in Nederland?

T. de Groot & M. Wasscher, 1999. Has Leucorrhinia pectoralis shifted its habitat in The Netherlands? Brachytron 3(2): 18-25. At the moment Leucorrhinia pectoralis is a rare and declining species in the Netherlands. The species is listed as “threatened” in the Dutch Red List. During the first half of the century large numbers were found in several kinds of habitats, such as marshland near rivers, and also coastal dune lakes. Usually these habitats were mesotrophic with a well-developed riparian vegetation. Nowadays there are two main habitats: small mesotrophic waters on sandy soils and peat marshes. Numbers on sandy soils have decreased dramatically and the species is now only recorded sporadically there. On the other hand, large numbers (up to 40 individuals on a 150 m. stretch of ditch) have been found in De Wieden and Weeribben, two peat marsh areas in the northwestern part of the province of Overijssel, in the last few years. It is not clear whether these populations had been overlooked in the past, or whether this species has only recently developed higher numbers here. Currently, the region supports one of the largest populations in northwestern Europe.