||Project is aimed at small aquatic biotopes, very important regarding their biodiversity, yet often overlooked and understudied. Project is logically linked to previous projects of team members. Proposed is reasonable improvement of datasets on communities of natural biotopes in lowland and mountain regions, new data will be acquired on human impacted areas, including robust environmental data. Macrophytes, molluscs, zooplankton and aquatic insects were chosen as model groups due to their indication value, different ecological requirements and function in food webs. Main goal is to understand patterns of biological diversity of small water bodies, emphasizing 1) evaluation of the importance of different biotope types for biodiversity preservation, 2) assessment of dispersal and habitat features roles in metacommunity structure and 3) describing extent of connectivity within metapopulations. Reaching the goals will improve effective conservation of aquatic ecosystems – important component of global environment.