The ant fauna (Hymenoptera: Formicidae) of the Mordovia State Nature Reserve, Russia

Ants form an important insect group in many terrestrial ecosystems. The research of ant species diversity is a relevant line of ecological and faunistic studies to completely reveal the biodiversity. Particular attention is given to Protected Areas where a high level of ant species diversity is known. The study of ant fauna and ant community structure was carried out in the Mordovia State Nature Reserve in 2014–2020. Material has been obtained using hand collecting, on census routes, and using carbohydrate and protein baits. The annotated list of ants in the Mordovia State Nature Reserve includes 42 species belonging to 11 genera and three subfamilies. Of them, 17 species are reported for the first time in this Protected Area. Most ant species belong to the genera of Formica, Lasius, and Myrmica, which amount to approximately 75% of the ant species richness in the Mordovia State Nature Reserve. The zoogeographical analysis of the ant fauna demonstrated seven geographical range types with a predominance of the European-West-Siberian and North-Palaearctic ranges. The ant diversity was analysed using the Renyi diversity profile based on census route data. The spatial distribution of ant species was estimated using detrended correspondence analysis. We found a high level of ant species diversity, conditioned by the effect of species evenness in the Mordovia State Nature Reserve. The most species-specific habitats were pine (Pinus sylvestris) forests with Convallaria majalis predominance in herb layer, linden (Tilia cordata) forests with participation of Betula pendula and Picea abies, dry Poa pratensis-dominated meadows, and moist meadows with predominance of Lupinus polyphyllus. The differences between the studied habitats were determined by microclimate conditions for specific ant species. On the model plots, the ant species density was about 7 species per 100 m2 in average.