The functional organisation of the mesopedobionts community of sod pinewood soils on arena of the river Dnepr

Abstract

We revealed the functional groups of the animals of sod pinewood soils (arena of the river Dnepr in the "Dneprovsko-Orelsky" Nature Reserve) on the basis of cluster analysis of the RLQ-axes received as result of interaction of matrix of community, matrix of edaphic parameters and matrix of ecomorphs of soil animals. The quantitative account of soil mesofauna has allowed us to establish that the community of animals inhabiting sod pinewood soils is represented by 20 species at a density of 68.9 ± 14.6 ind./m2, 8 forms were identified at the level of genus, family or order. Two species were represented by their larval and imago phases (Anatolica eremita (Steven, 1829) and Calathus ambiguus (Paykull, 1790)). A count of animals conducted in an alternative way has allowed us to expand the list to 38 species or forms at species level. The level of abundance and diversity for sod pinewood soils on the arena is not high compared with other types of soils of the arena of the river Dnepr. This result shows that the community has a simplified ecological structure. The prevailing ecological structure of the community can be characterised as steppe, xerophilous, oligotrophocoenomorphic. Anecic animals are absent from the topomorphic structure and saprophagous animals absent from the trophic structure. Only additional collection by alternative methods has allowed us to establish the presence in the community of saprophagous and anecic animals. The latter ecological group is represented by the extremely mobile vertebrate species Pelobates fuscus. The foromorphic structure of the community differs by its great variety. In this structure various strategies of animals’ movement through the soil are proportionately represented. On the one hand, we see various ways of movement of herpetobiont animals, mainly insect imagoes, which as a whole differ in their considerable migratory potential. This circumstance staticizes the historical reasons for the formation of the studied community. On the other hand, in the community there are various strategies of movement in the soil that allow us to assume or determine the reasons or causes of structurization of an ecological niche. Environmental factors are described by two groups of indicators, edaphic properties and values of phytoindicator scales. The mesopedobionts community structure is presented as a classical matrix of species/sampling points. The ecology of communities is principally focused not on taxonomic features but on biological properties (traits) of species. Such features can act on ecomorphs of soil animals. The direct functional analysis of relationship of biological properties of species with variables of environment by means of data on the abundance of species demands association of three matrixes of data. Such problem can be tackled by means of the RLQ-analysis. A key aspect of structurization of communities of soil mesofauna is differentiation in trophic traits. The organisation of a community of soil animals in an ecological space set by axes RLQ can be displayed in the form of a natural variation of RLQ-axes in geographical space. Everything in the RLQ is represented, as follows from the mathematical nature of this generalisation, an independent aspect of the coordinated variation of structure of a community of soil animals, properties of environment and ecomorphic features of mesopedobionts.