Microspatial distribution of molluscs and response of species to litter moisture, water levels and eutrophication in moist, alkaline ecosystems

Abstract

We investigated the influence of litter moisture, water levels and eutrophication on the microspatial distribution of terrestrial molluscs as well as their responses to the aforementioned factors. The studies were carried out in two moist, alkaline habitats in western Poland, differing in a range of environmental conditions. Redundancy Analysis showed that litter moisture was the leading factor affecting the microspatial distribution of the snails. To analyse the relationships between species abundance and litter moisture and water levels we determined a generalized linear model (GLM). The results of the analysis show that the abundance of the majority of the species decreased with increasing eutrophication. The abundance of the majority of species increased with increase in litter moisture at the Ilanka site, whereas conversely at the Pliszka site, the majority of the species showed a decreasing abundance with increasing litter moisture. The limiting factor at the Pliszka site was probably local inundations as well as litter and plant cover.