Publication details
Aquatic mollusc metacommunity structuring in lentic habitats of two regions differing in trophy level
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| Year of publication | 2019 |
| Type | Conference abstract |
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| Description | The highest freshwater mollusc diversity was repeatedly found in lowland standing waters. Despite the increasing negative anthropogenic impact of these habitats, still only little is known about the main drivers of mollusc diversity among individual stagnant water bodies at regional scale. It is assumed that different processes control mollusc assemblages in oligotrophic and eutrophic sites because many mollusc species are associated with a high macrophyte cover. Besides environmental filters, freshwater mollusc distribution reflects interconnection among individual sites via active vectors due to passive dispersion mode of molluscs. Further, the distances between sites govern the success of mollusc migration to new habitats, being also link with their long-term survival in a dynamic environment. In this study, we quantitatively sampled mollusc assemblages in two regions differ mainly in productivity and trophy level. In the Dyje River floodplain (south-east Czechia, 56 sites sampled), 33 species were found, while in lakes of Dumre (middle Albania, 22 sites), only 9 mollusc species were recorded. While Albanian sites are isolated, oligotrophic (of low phosphorus and calcium concentration), the Czech sites are highly interconnected and eutrophicated. We hypothesized that 1) the habitat heterogeneity, productivity and interconnection significantly influence mollusc species richness and distribution in both regions; 2) species sorting is a dominant process structuring the mollusc metacommunity at small spatial scales; and 3) anthropogenic changes lead to the homogenization of environmental characteristic of sites, and thus to a homogenization and decrease of mollusc regional diversity. |