In a study on the click beetles (Coleoptera: Elateridae) of selected plant communities of the Lasy Janowskie Reserve, 21 species of these beetles were recorded – 10 each in riparian forests and a sub-Atlantic mesic coniferous forest, 11 in a continental mixed coniferous forest, and 6 in wet grassland communities. The numbers of species in the communities was similar to numbers recorded in other, comparable areas of Poland, with the exception of the wet grasslands. Forest species that can also occur outside of forests – Athous subfuscus and Dalopius marginatus – were dominant. The biodiversity of the click beetle fauna in the communities was at an average level. An ecological and zoogeographical analysis was carried out as well.
In two fish ponds in Lasy Janowskie Landscape Park 48 water mite species were caught. In the pond Momoty Duże, situated in the Lasy Janowskie reserve, more species (38), higher species diversity (3.88), and a larger share of lake fauna (33.2%) were observed than in Momoty Małe (33, 3.67 and 22.6% respectively). In the combined collected material small water body species were dominant (70.6%). Similarity between the Hydrachnidia assemblages of the two ponds was 50.1%. The large number of species and individuals caught and the high values for the species diversity index confirm the significant role of fish ponds as a habitat for water mites. A characteristic trait of the ponds was the very small percentage of vernal species and of tyrphobiontic and tyrphophilic species. Although more species and a larger share of lake fauna were found in the pond situated in the reserve (Momoty Duże) than in the pond outside the reserve (Momoty Małe), the differences in the structure of the fauna were slight. The lack of pronounced differences between the two ponds was due to their similar habitat characteristics and similar use.