Vertical distribution of Collembola in deciduous forests under Mediterranean climatic conditions

This study was conducted in the deciduous forests in the delta of the river Nestos. Soil samples were taken in various seasons and were divided into three layers: O layer, 0-2.5 cm soil depth and 2.5-5 cm soil depth. The Collembola caught were counted and identified and the biomass was determined. Soil moisture and temperature were also recorded. In most seasons the majority of the animals was found in the O and the upper soil layer. Under adverse conditions in summer (low soil humidity) a vertical migration to deeper layers was observed. No similar response was observed in winter. These patterns persist at the level of the whole Collembola population and at the species level as well. Only minute differences, if any, were observed in the vertical distribution pattern of the most abundant species, irrespectively of the life form they belong to. Generally a preference of smaller animals for the deeper layers was observed.