Effects of temperature and moisture fluctuations on an experimental soilmicroarthropod community

摘要

We established an experiment in microcosms with coniferous forest humus and birch leaf litter for testing the effects of constant vs. diurnally fluctuating temperature and uniform vs, varying moisture, on the population densities and species richness of Collembola and Mestostigmata. These parameters and the vertical distribution of populations were analysed by layers (top, centre, bottom) at two samplings (weeks 10 and 27). The hypotheses were that populations of at least some species benefit from fluctuating microclimate, and that varying conditions permit more species to coexist than uniform conditions. At fluctuating temperature regime, four species and total Collembola were more abundant, and species richness of Collembola was higher. One mite species and total Mesostigmata were more numerous at constant temperature. One collembolan species was more abundant at varying moisture, and one mite species at constant moisture. We conclude that the data support our hypotheses, though the observed differences between treatments were not very marked. Some species appeared to share their environment vertically.