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Knijf, G. de; Anselin, A.; Goffart, P.. |
Trends 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... |
Tipo: Article in monograph or in proceedings |
Palavras-chave: Odonata; Dragonflies; Belgium; Atlas; Hot spot; Abundance class shift; Habitat; 42.75. |
Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/219852 |