A multiscale approach to evaluate the structure of diversity of Collembola in boreo-nemoral forests of the Russian Plain

Collembola is a group of numerous ubiquitous small soil-dwelling arthropods decomposing the plant residues. The study analyses the diversity structure of this group in mesic conditions of coniferous, mixed, and broad-leaved forests. Sample plots were located in three Protected Areas in the Moscow Region (Losiny Ostrov National Park and the Valuyevsky Forest Park) and Smolensk Region (Smolenskoe Poozerye National Park). In total, 70 species of Collembola were registered in the forest litter. Two Collembola species were of Asian origin, namely Appendisotoma stebayevae (noted in Europe for the first time) and Vertagopus asiaticus (the second record of this species in the study area). The number of species was close to the number of genera, indicating the allochthonous character of the forest fauna of Collembola of the central Russian Plain. A multiscale approach was applied for sampling design. This allowed us to assess the diversity of Collembola at various spatial scales: from 1 m to hundreds of kilometres. The study scheme included two regions, four localities, 12 sample sites, and 36 plots; the latter was 1 m2 (the smallest area unit). The data analysis was based on the concept of alpha-beta diversity accompanied by the additive partitioning method. The region (the largest area unit) was the most important factor in forming the species diversity. The type of forest litter (coniferous vs. broad-leaved) was less significant; the habitat heterogeneity factor made even a less contribution. On average, 1 m2 of forest litter comprised about a quarter of the entire list of Collembola species in the studied forests. The species richness of Collembola in the broad-leaved forests was more variable in space and in time compared to coniferous forests and mixed forests; a transitional pattern was observed. The species composition of Collembola varied between the seasons of the year by about a quarter when considering the same sites of coniferous and mixed forests. In broad-leaved forests of various areas, seasonal changes in species composition varied highly, from very pronounced to insignificant. The new concept of plant litter traits is discussed as a factor for affecting the patterns of the structure and dynamics of the Collembola species diversity