Env Exp Biol (2010) 8: 59–69

Occurrence of grass-dwelling spiders in habitats of Lake Engure Nature Park

Abstract

Ecological studies on spiders in the territory of Latvia have not been conducted recently. We describe grass-dwelling spider fauna in 12 different habitats within the area of Lake Engure Nature Park. Spiders were collected by three sweep-nettings per year during a 12‑year period (1997 – 2008). More than 149 taxa from 19 families were identified. On the basis of similarity in spider fauna shown by cluster analysis, the habitats were divided into two groups. The first group included mostly dry habitats, such as dry wooded meadow, dry coastal meadow, moist coastal meadow, dry pine forests, wet deciduous forest and wet pine forest. The second group were characterised by wet habitats – marshlands and moist calcareous meadow. Dry pine forest was not included in any group due to a low species number and completely different fauna from the other habitats. Only three species were present in a particular habitat for nine or more years: Linyphia triangularis (in a dry pine forest on grey dunes and in a dry pine forest on mineral soil), Tibellus maritimus (in a calcareous fen) and Evarcha falcata (in a dry pine forest on mineral soil).