Species associations and trait dissimilarity in communities of ectoparasitic arthropods harboured by small mammals at three hierarchical scales

Abstract

1. This study tested the relationships between the probability of pairwise species co‐occurrence and pairwise dissimilarity in their traits in infracommunities (across assemblages harboured by conspecific individual hosts within a locality), component communities (across assemblages harboured by host species within a locality), and compound communities (across assemblages in different localities) of fleas and gamasid mites parasitic on small mammals in Western Siberia. 2. A significant, albeit weak, tendency was found for flea communities harboured by conspecific host individuals, host species, and host communities to be composed of similar species. No relationship between the probability of co‐occurrence and trait dissimilarity was detected for mite communities at any hierarchical scale. 3. For fleas, this study explained the link between positive co‐occurrence and trait dissimilarity by a process resembling environmental filtering realised mainly via host traits for infracommunities and component communities and via off‐host environment for compound communities, thus suggesting that the identical shape of the relationships between co‐occurrence and trait dissimilarity at different scales was driven by different mechanisms. 4. The explanation of the lack of this relationship in mites included: (i) the paucity of the subset of mite traits used in this study and its potential inadequacy for the question at hand; and (ii) possible masking of the effect induced by one trait on co‐occurrence owing to the lack of this effect induced by another trait(s). 5. Caution is recommended regarding the compilation of a dataset involving multiple traits, its analysis, and the interpretation of the results.

Species associations in arthropod ectoparasite infracommunities are spatially and temporally variable and affected by environmental factors

“…Surprisingly, the majority of the interspecific interactions revealed by the CRFs were negative, whereas early analyses suggested an aggregative structure of flea and mite infracommunities harboured by small mammals, with the number of interspecific positive associations being either higher than or approximately equal to the number of negative associations (Krasnov et al, 2006a(Krasnov et al, , 2011(Krasnov et al, , 2019Vinarski et al, 2020). The main reason behind this contradiction between the current and the earlier studies is the profoundly different analytical approaches.…”

Spatial and temporal variation of compositional, functional, and phylogenetic diversity in ectoparasite infracommunities harboured by small mammals

“…(2006 b ) and Vinarski et al . (2020) found positive species co-occurrences in flea infracommunities. These results and the results of the present study indicate a process resembling environmental filtering (in our case, filtering via some features of a host individual) as a governing force of species assembly in infracommunities.…”

“…Previously, environmental filtering as the main mechanism of community assembly from compositional, functional, and phylogenetic perspectives has been shown for component and compound communities of fleas and mites (Krasnov et al ., 2015 b , 2019 a , 2019 b ; but see Vinarski et al ., 2020 for mites). We thus may conclude that the patterns of assembly in ectoparasite infracommunities mirror those characteristic for their component and compound communities.…”

“…Life history variables (all categorical) were microhabitat preference (higher or equal proportion of time spent either on a host's body or its shelter; see Krasnov, 2008) and seasonality of reproduction (the peak during either the warm or cold period or no seasonal preference) for fleas and feeding mode (exclusive blood-feeding, blood-feeding and predation upon other nidicolous arthropods, or intermittent non-obligatory blood-feeding and predation; Radovsky, 1985) for mites. Additional details on the measurement of flea and mite traits can be found elsewhere (Krasnov et al ., 2019 a ; Vinarski et al ., 2020).…”

Plant co-occurrence patterns and soil environments associated with three dominant plants in the Arctic

“…However, from early studies of plant community ecology, there have been debating views concerning the processes that assemble plant communities (Götzenberger et al 2012). A biological community may contain either a random set of species or be structured by certain assembly rules (positive or negative relationship) (Vinarski et al 2020). Plant-plant interactions in communities strongly affect the community structure and dynamics and can thereby determine which species can coexist (Padilla and Pugnaire 2006).…”