Effects of wet grassland abandonment on invertebrate communities

Wet grasslands are biodiverse wetlands managed for agricultural production, but many are threatened by land abandonment. Effects of abandonment on vegetation are known but few studies have focussed on other ecosystem components, especially invertebrates. This study sampled soils, vegetation, and invertebrates in 27 managed, short-term abandoned and long-term abandoned wet grasslands in Estonia to elucidate the effects of abandonment on invertebrate communities. Results showed that there were no significant differences in diversity between management types for invertebrates collected from pitfall traps or net transects, and community differences between management types were modest. For transects, there was a significantly greater total number of invertebrates in short-term abandoned than managed grasslands. There were significantly more Coleoptera in long-term abandoned than managed sites, although this was not strongly associated with differences in soil or vegetation characteristics. For pitfalls, there were significantly more Arachnids in managed grasslands compared to long-term abandoned sites, which was not clearly related to soil or vegetation variables. There were significantly more Myriapods in pitfalls in long-term abandoned sites than other sites, and in transects Myriapods were associated with organic, nutrient-rich, moist soils and an abundance of plant litter and Urtica dioica. The results suggest abandonment of wet grasslands does not affect invertebrate diversity significantly but favours some taxa, thus management facilitating successional patches across the wetland landscape would be beneficial for invertebrates.