Abstract. Macrozoobenthos as an important component of all aquatic habitats is very diverse community of aquatic invertebrates, which are either throughout its life, or during the developmental stages bound to the water. Representatives of this community are extremely sensitive to environmental conditions in which they live, but especially to the qualitative properties of water. They are suitable bioindicators of any characteristics changes of their habitat. Therefore, permanent occurrence, but, for the majority of the representatives of the benthic fauna, relatively long development cycle conducted in water, can significantly influence not only natural factors, but also human activities. In this work we present results of the occurrence of macrozoobenthos communities in two nature reserves in southwestern part of the Slovak Republic: Žitavský luh and Alluvium Žitavy, while also evaluate the potential impacts of agricultural activities on the species and numerous representations in the monitored habitats. In 2006 and 2007, we are on each monitored aquatic habitats, in six sampling sites at regular quarterly intervals collected total of 48 water samples, together with biological material. In Nature Reserve Žitavský luh we recorded in 24 taken samples 25, 966 individuals, determinate to be 135 species of benthic fauna. In Nature Reserve Alluvium Žitavy by collecting of 24 samples of water we obtained only 12, 708 individuals, 126 species of this ecological group of individuals. Determined species were included in the 15 systematic groups: Turbellaria, Gastropoda, Bivalvia, Oligochaeta, Hirudinea, Isopoda, Amphipoda, Ephemeroptera, Odonata, Heteroptera, Megaloptera, Coleoptera, Trichoptera, Diptera (without Chironomidae) and Chironomidae. Of these, the numerically and percentage the most involved on the structure of macrozoobenthos community Gastropoda, Isopoda, Ephemeroptera and individuals of families Chironomidae. The contrary, the lowest share in numerous, species and percentage representation had Megaloptera, Turbellaria and Odonata. From the total number of 177 determined species of benthic fauna in the territory of Slovakia is 23 species protected by law under the legislation of the State Nature and Landscape Conservation, included primarily to the species categories: VU – vulnerable and LR: nt – near threatened. In the monitored period were structure and biodiversity of macrozoobenthos communities of Nature Reserve Žitavský luh compared with structure and biodiversity of Nature Reserve Alluvium Žitavy richer and more balanced. Significant negative impact of agriculture on the macrozoobenthos community in that period in monitored aquatic habitats was not recorded.

Key words: Agroecosystems, macrozoobenthos, water, protected area, Slovak Republic

Presentation: oral