Edaphic Collembola assemblages of European temperate primeval forests gradually change along a forest-type gradient

- Collembola assemblages of Białowieża Primeval Forest are forest-type dependent.
- Springtails are more abundant in wet and boggy deciduous forests than in coniferous forests.
- Collembola species are more affected than assemblages by forest type.
- One-third of the species qualified as significant indicators of forest type or forest-type group.

The Białowieża Primeval Forest is the largest remnant of temperate virgin forest in central Europe. To investigate the relationship between forest type and edaphic Collembola assemblages, we established 36 study sites in the Strict Nature Reserve that represented the most valuable old growth forest stands and included most of the variability in forest type. The faunas of the humid and boggy deciduous forests were more abundant than those of the moderately humid forests. Three primary groups of assemblages were revealed by multivariate analysis to be typical of the following forest types: (i) coniferous bog forest, (ii) humid and moderately humid coniferous forest, and (iii) deciduous forest. Collembola assemblages were only moderately related to specific forest types but instead changed continuously along the environmental gradient that they formed. At the species level, the correlations to forest type were stronger, and approximately one-third of the collembolan species qualified as significant forest type indicators; both forest specialists and forest generalists were identified. Six species were revealed to be forest generalists because they indicated a wide spectrum of forest types. Nine species were significantly correlated with four to six forest types and were identified as broad specialists, and seventeen indicator species were associated with one, two or three forest types and were classified as narrow specialists. Because the correlation between the edaphic Collembola faunas and forest type revealed a gradual rather than categorical change in the community assemblages, we suggest that this relationship be considered in the development of future forest monitoring programmes.