Dragonflies (Odonata) of the Nowiny Nature Reserve (Roztocze Upland, south-eastern Poland). In 2020 the fauna of dragonflies was studied in the Nowiny Nature Reserve comprising of 5 midforest land depressions with strongly hydrated transitional and raised bogs, some with water bodies. 33 species were recorded (46% of the national fauna), 29 of which were autochthonous or probably autochthonous. In these depressions, 14 to 24 species were recorded. The fauna was dominated by stenotopic species of peat bogs and eurytopic species. Moreover, individual species indicating the drying process of some of the sites (Lestes dryas) as well as instability of assemblages (Libellula depressa) were recorded. A limnophilous species Anax parthenope was recorded on the site with the largest water body (0.27 ha). In the summer, the high number and high breeding activity of thermophilous Aeshna affinis were observed. In general, the Nowiny Nature Reserve is an important area for the protection of peat bog fauna because of the odonate assemblages and the occurrence of such species as Aeshna subarctica and Somatochlora arctica. However, the absence of some expected species (e.g. Aeshna juncea and Leucorrhinia dubia), low number of some specialists (e.g. Leucorrhinia rubicunda) as well as intensive colonization of the researched area by Aeshna affinis may suggest the change of its fauna. It is not resulted from the degradation of habitats, but rather from the climate warming which is unfavourable for Siberian dragonflies sensu St. Quentin (1960) and favourable for thermophilic ones. Probably in the southern part of Poland, stronger decline of species from the first group is in progress with the simultaneous expansion of species from the second one. These two processes involve not only geographical ranges, but also extending the habitat base. It may intensify the problem with protection of tyrphobionts and tyrphophiles, a part of which is already endangered.