The more diverse beaver ponds are better – a case study of mollusc communities of steppe streams
In: Wetlands. Official Scholarly Journal of the Society of Wetland Scientists. Society of Wetland Scientists (SWS)/Springer: Wilmington. ISSN 0277-5212; e-ISSN 1943-6246, more
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| Authors | | Top |
- Bashinskiy, I.W.
- Stojko, T.G.
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| Abstract |
The factors influencing molluscs distribution in a small steppe stream were investigated to assess the impact of beavers on their diversity and abundance. Twenty stations—in unaffected streams, beaver ponds at different stages of development, and anthropogenic ponds—were sampled in May 2019 and June 2021. In each pond, a nearshore area of 1 m2 was completely surveyed using a dip net. Twenty-one mollusc species were found. Old and drained beaver ponds were characterized by significantly higher species richness. The damming of the river, by both humans and beavers, initially resulted in decreased species diversity, then followed by increased species richness due to increased habitat heterogeneity across the valley. Maximum gamma biodiversity was observed when the river habitats included all types of beaver ponds. When ponds were abandoned, a short-term increase in mollusc biodiversity and abundance was observed. Afterward, channel processes returned the habitats to a lotic state, habitat heterogeneity began to decrease, and mollusc community evenness dropped dramatically. To conserve the mollusc biodiversity of the stream valley, it is necessary for beavers to permanently renew some ponds. |
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