Long-Term Dynamics of Collembolan Populations in Forest and Meadow Ecosystems

摘要

The population dynamics of soil-dwelling springtails in a spruce forest (Piceetum oxalidosum) and a dry meadow with young planted spruce trees was analyzed based on an eight-year sampling in Moscow Region. Fluctuations of population densities of the most species are less than 10 fold. The seasonal dynamics (the number and position of peaks) is more constant in surface-dwelling species than in hemi- and euedaphic ones. The occurrence of the density peaks in specific seasons is merely a tendency. Two types of the size structure of populations are revealed: the "left-sided" type with prevalence of small immature individuals and the "symmetrical" one with prevalence of medium-sized individuals. Synchronization of reproduction in the species studied is possible only under the effect of external climatic factors. The seasonal density dynamics of most abundant species is related to the temperature and, to a lesser extent, precipitation. The mean density of some species in the following year can be predicted based on the mean temperature and/or sum of precipitation in the current year. In the forest, the density-dependent regulation of springtail abundance is probable. The springtail populations do not respond to overgrowing of the meadow with spruce trees at least at the beginning of this process.