A spider taxonomy and ecology field course was organised in Kilpisjärvi Biological Station, northern Finland, in July 2019. During the course, four 50 × 50 m plots in mountain birch forest habitat were sampled following a standardised protocol. In addition to teaching and learning about spider identification, behaviour, ecology and sampling, the main aim of the course was to collect comparable data from the Kilpisjärvi area as part of a global project, with the purpose of uncovering global spider diversity patterns.
A total of 2613 spiders were collected, of which 892 (34%) were adults. Due to uncertainty of juvenile identification, only adults are included in the data presented in this paper. The observed adult spiders belong to 51 species, 40 genera and 11 families, of which the Linyphiidae were the most rich and abundant with 28 (55%) species and 461 (52%) individuals. Lycosidae had six species and 286 individuals, Gnaphosidae five species and 19 individuals, Thomisidae four species and 24 individuals, Theridiidae two species and 23 individuals. All other six families had one species and less than 40 individuals. The most abundant species were the linyphiid Agnyphantes expunctus (204) and the lycosids Pardosa eiseni (164) and Pardosa hyperborea (107).
Vegetation Changes in the Nordic Mountain Birch Forest: the Influence of Grazing and Climate Change