Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Invasion of the neophyte Spiraea sp. and succession of species-rich grasslands: impacts on the communities of spiders (Araneae), ground beetles (Carabidae), millipedes (Diplopoda) and centipedes (Chilopoda).

Abstract

Species-rich grasslands are endangered throughout Central Europe, one cause being the abandonment of these habitats. As a result, especially competition-poor and specialized species can disappear in the short to medium term. A particular danger is rapid shrub encroachment by species possessing runners, such as invasive neophytes of the genus Spiraea, which have developed dominant stands in Upper Lusatia on both sides of the German-Polish border for several decades, e.g. in wet meadows and their fallows. The present study investigates the impact of meadow abandonment in northern Upper Lusatia under the influence of these neophytes. For this purpose, a meadow, a fallow and a dominant Spiraea population (S. douglasii and S. tomentosa respectively) were examined in each of three study areas by means of pitfall traps, whereby spiders, ground beetles, millipedes and centipedes were recorded at the species level. A total of 12,045 spiders from 173 species, 2,356 ground beetles from 69 species, 241 millipedes from 9 species and 145 centipedes from 7 species were detected. The communities of the various habitat types differed clearly from each other. The difference between the assemblages of the fallows and the meadows were less than between shrubs and open areas. Spiraea sites harbored fewer species and individuals of spiders and ground beetles than the other two habitat types. In addition, the extreme change in conditions in the Spiraea sites led to a shift in species composition towards forest communities, where species of open sites were less common and xerophilous specialists disappeared. Nevertheless, endangered or rare species of all investigated animal groups were also found among the Spiraea sites.