Water mites (Acari, Hydrachnidia) in three forest and landscape reserves in Roztocze

The materials of water mites collected in 1973–1974 in aquatic environments of three nature reserves in Roztocze were characterized. The collections comprised 995 Hydrachnidia belonging to 49 species. Twenty-eight species were collected in the Nad Tanwią Reserve, 30 species – in the Czartowe Pole Reserve, and 24 species – in the Szum Reserve. The analyzed reserves cover short river sections, therefore, the evaluated fauna can be regarded as relatively rich. The fauna of the examined reserves included widely distributed species as well as species typical of montane and submontane areas. In the analyzed reserves, the water mite fauna was dominated by rheobionts and rheophiles, and it was characteristic of upland rivers in the Lublin Region. One species new to Poland was identified: Atractides albaruthenicus Cich. et Bies. A comparison of the water mite fauna from the Nad Tanwią Reserve with the materials collected in 2001–2002 points to a significant reduction in the number of water mite species and considerable changes in the structure of synecological groups.