bioindication; Odonata; management; secondary habitat; broadleaf forest; urban landscape; insect conservation

These are the results of the very first inventory research of assemblages of dragonflies (Odonata) in the Ostrava Zoo carried out in 2019 and partly in 2020. The aim of the study was to give information about assemblage of dragonflies situated into area of Ostrava zoo. Species richness has reached 25 species (8 of Zygoptera, 17 of Anisoptera). Dragonflies were used to indicate environmental and ecological factors for the purposes of protecting their local species richness. This land of about one hundred hectares has never undergone land consolidation and there is no large-scale spraying and fertilization. Flow ponds, dams and wetlands created primarily in wooded areas seem to be an ideal retreat for dragonflies. The creation of a favourable environment for dragonflies also contributes to the springs and runoffs from ponds. These exceptional habitats can serve as significant refuge of endangered species like Libellula fulva and Orthetrum coerulescens. Much of this species-richness of Odonata may be due to the diversity and abundance of littoral macrophytes. In cases artificially planted littoral can lead into an ecological trap for larvae development because of quantity of fish. Especially carps causing turbidity and eating larvae and also overgrowing of water levels by Lemnoideae plants eutrophication, reducing the oxygen content in the bottom and decreasing its attractiveness for reproduction can be factors negatively affecting the occurrence of dragonfly assemblage in certain localities.

These are the results of the very first inventory research of assemblages of dragonflies (Odonata) in the Ostrava Zoo carried out in 2019 and partly in 2020. The aim of the study was to give information about assemblage of dragonflies situated into area of Ostrava zoo. Species richness has reached 25 species (8 of Zygoptera, 17 of Anisoptera). Dragonflies were used to indicate environmental and ecological factors for the purposes of protecting their local species richness. This land of about one hundred hectares has never undergone land consolidation and there is no large-scale spraying and fertilization. Flow ponds, dams and wetlands created primarily in wooded areas seem to be an ideal retreat for dragonflies. The creation of a favourable environment for dragonflies also contributes to the springs and runoffs from ponds. These exceptional habitats can serve as significant refuge of endangered species like Libellula fulva and Orthetrum coerulescens. Much of this species-richness of Odonata may be due to the diversity and abundance of littoral macrophytes. In cases artificially planted littoral can lead into an ecological trap for larvae development because of quantity of fish. Especially carps causing turbidity and eating larvae and also overgrowing of water levels by Lemnoideae plants eutrophication, reducing the oxygen content in the bottom and decreasing its attractiveness for reproduction can be factors negatively affecting the occurrence of dragonfly assemblage in certain localities.