Non-Random Patterns, Seasonality and Structure of Soil Collembola Communities in the Nestos River Delta, Greece

A central goal in ecology is to understand whether community assembly follows deterministic rules or is of a stochastic nature. Although species co-occurrence is extensively documented and studied for vertebrates, applying these frameworks to soil Collembola communities in Mediterranean riparian systems provides essential comparative data for community assembly theory. This study examined soil Collembola communities in the Nestos River delta (Greece) across diverse seasons and habitats using thirty-two presence–absence matrices based on abundance data for fifty-four species. These were analyzed using several metrics, each with appropriate randomization algorithms. We studied these metrics across seasons to track community structure changes over time. Additionally, the use of an appropriate multivariate method quantified the influence of soil humidity, while seasonal variations in biomass and diversity were tracked to explore biotic and abiotic influences. In most cases, null hypotheses about the forces structuring these communities could not be rejected, although some instances suggested competitively structured communities. Overall, soil humidity was found to modestly influence community structure, while concordant seasonal trends among biomass and diversity suggest that environmental filtering and biotic interactions shape the observed patterns, with temporal dynamics appearing relatively consistent across habitats within the study year.