Carabids of the Iron Gates: Diversity assessment and conservation

Abstract

By number of species, arthropods represent the most dominant animal group on Earth. Majority of these species belong to insects, especially beetles. Ground beetles (Carabidae) are among the most speciose families of all animals and they have populated almost every land habitat. Carabids feed both on plant and animal food; they are good ecological indicators and important natural enemies of many invertebrate pest species. In Europe, the knowledge about carabids is biased towards species living in western and northern regions, while the southern part of the continent is less explored in this manner, despite having considerably richer carabid fauna. This is supported by the fact that even today, new endemic taxa (species or even genera) unknown to science are described from certain habitats of Serbia and other Balkan countries. This region is widely recognized as one of the Europe’s biodiversity hotspots. Đerdap National Park in Serbia has a very rich flora and fauna, which is endorsed by the international recognition as an important habitat area for many species of plants, birds and butterflies. Our goal was to assess carabid diversity in the Đerdap since no such specifically targeted study is conducted in the past. We selected over a dozen localities in different habitats and collected ground beetles by pitfall trapping and manually from April to November 2017. In addition, we carried out a preliminary assessment of threatening factors during our field trips in order to establish the foundations for further conservational research of rare and endemic carabids in the mountains of eastern Serbia. Our results show rich ground beetle fauna in the park, since we have identified 141 species belonging to 56 genera and 13 subfamilies (checklist is based on oneseason research funded by the Rufford Foundation). We located important local carabid populations such as Carabus versicolor simulator Kraatz, 1876 and C. ullrichii arrogans Schaum, 1858. Additionally, we found several other rare species, a few species with the first precise record(s) in Serbia, like Chlaenius aeneocephalus Dejean, 1826, and one species so far unregistered in Serbia. We recognized Golo brdo, Mt. Liškovac, Boljetinska reka Canyon and Poreč Bay as most valuable and protection worth localities of the park since we found many rare and endemic taxa on these sites. The main threatening factors for carabids can be deforestation, forest fires caused by human neglect and alteration of Danube riparian areas as well as the banks of the smaller tributaries.