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AuthorsG. de Knijf, A. Anselin, P. Goffart
TitleTrends in dragonfly occurrence in Belgium (Odonata)
PublisherEuropean Invertebrate Survey - the Netherlands
Book/source titleChanges in ranges: invertebrates on the move. Proceedings of the 13th International Colloquium of the European Invertebrate Survey, Leiden, 2-5 September 2001  
EditorsM. Reemer, P.J. Helsdingen, R.M.J.C. Kleukers
KeywordsOdonata; Dragonflies; Belgium; Atlas; Hot spot; Abundance class shift; Habitat
AbstractTrends in dragonfly occurrence in Belgium (Odonata)
The group ‘Gomphus’ collected 65 000 records of 69 species of Odonata, more or less equally scattered over Belgium. The best-investigated areas are the northern part and some river valleys in the south. Most hot spots can be found in the northeastern part, with a maximum of 48 species for 25 km². Remarkable is the fact that 50% of the species occurs in less than 7% of the 5 km grid cells (UTM). We determined trends in occurrence by comparing three periods: before 1950, 1950-1989 and 1990-2000. Four species show a clear decline over the three periods, eight species give evidence of a historical decline but survive on a limited number of sites and eight species also display a historical decline but have been increasing during the last decade. Six species show a (very) clear increase over the three periods and two species display their increase only during the last ten years.
Document typechapter
Download paperpdf document http://www.repository.naturalis.nl/document/46392