Long-term dynamics of a collembolan community

Abstract

The collembolan community of a beech forest on limestone (Göttingen, Germany) was studied for a period of ten consecutive years (1980–1989). A total of 48 species was found. The annual mean density varied between 18 600 and 46 800 ind. m −2 yr −1. Abundance dynamics of the different species were not significantly intercorrelated. Year-to-year changes in annual mean temperature were significantly correlated with alterations in collembolan density in the following year. Specific differences in response patterns to temperature alterations apparently buffered each other in such a way that the response of the whole community to temperature is more predictable than that of most individual species. No clear-cut trend in the abundance dynamics of the collembolan community were detected and the actual densities of the individual species were not correlated with the corresponding densities in the following year. On the other hand, indication of density dependent regulation was found for eight species. To explain this seeming contradiction it was hypothesized that at least part of the collembolan community is exposed to density dependent regulation and that strong year-to-year fluctuations in density are due to significant year-to-year changes in the carrying capacity of the soil environment caused by long-term effects of temperature on the quantity and quality of the litter layer.