Scale – pattern – habitat choice – life history: ecology of terrest-rial isopods (Isopoda, Oniscidea)

Abstract

Species of the suborder Oniscidea (Isopoda) are the most successful invaders of terrestrial habitats within the crustacean class. They are excellent models of terrestrial adaptation. Functionally, they are decomposers of the soil ecosystem. The most important results and conclusions summarized in the MTA doctoral dissertation: Regularities can be recognized in the distribution of species – developed on different scales and due to different background reasons. There is a latitudinal trend in Europe, which means a decreasing number of species north of the Mediterranean and a change in the biogeographical/ecological character of the species. The number of species and the degree of endem­ism are high in Mediterranean regions. The nature of the habitats of a geographical region determines its species richness and the naturalness of the species. We have expanded the interpretability of the species richness and diversity indices with indices that can be used to classify species and commu­nities. There is a close relationship between a habitat and its isopod fauna. Species can be classified based on their habitat, ecological needs and tolerance, or vice versa: the naturalness and disturbance of a habitat can be judged based on the species living there. Human activity plays a major role in the spread of species. The settlement of introduced species in cities is regular and decisive, causing biotic homogenization. There is a correlation between the morphological character of species and their ecol­ogical needs. The intra- and interspecific dynamics of populations differ in their life history strategies. Key environmental factors determine the temporal development of activity density. Female size and number of offspring are closely correlated, fecundity decreases over time regardless of female size.