Meeting Abstract
The environment may act as a “filter”, allowing a community to contain only species possessing traits necessary for persistence in that environment. Parasites are characterized by a “dual” environment, namely by their hosts and by abiotic (e.g., climatic) factors. We investigated the role of environmental filtering as an underlying mechanism of assembly of compound communities of fleas parasitic on Palearctic small mammals at two spatial scales: a continental scale (across the Palearctic) and a regional scale (within Slovakia). We used an expanded version of three table ordination that links species occurrences with space, environment, species traits and phylogeny. We asked whether environmental filtering acts as an assembly rule of compound communities of fleas and, if yes, (a) whether the effect of environment on species composition of compound communities of fleas differs between spatial scales and (b) what are the relative importance of the abiotic and host environments. We found that compound communities of fleas are, to a great extent, assembled via environmental filters that represent interplay between filtering via abiotic environment and filtering via host composition. The relative importance of these two components of environmental filtering differed between spatial scales. Host composition had a stronger effect on flea assembly than abiotic environment on the continental scale, while the opposite was true for the regional scale. The climate changes, thus, may affect species composition of fleas at local, but not regional scale. The likely reason behind this scale-dependence is that communities on the regional scale are mainly governed by ecological and epidemiological processes, while communities on the continental scale are mainly affected by evolutionary, biogeographic and historical forces.
