Climatic limits for the present European distribution of hornbeam (Carpinus betulus), with special reference to Ukraine

In this study, we used a ecological niche modeling approach to detect the importance of diverse climatic parameters in controlling the distribution of forest tree species, exemplified by the common hornbeam (Carpinus betulus L.), with special reference to Ukraine from where digitized data on the species has been scarce. In Ukraine populations of this tree species are found on the edge of its home range and are exposed to extreme climate conditions. The main objectives of the present study were to model the European-wide ecological niche of the common hornbeam and investigate primary climatic factors that control the potential distribution of this tree in Ukraine. Using an ecological niche modeling approach, we consider having reliably modeled the European-wide bioclimatic niche of the common hornbeam for predicting the response of species geographical distribution to climate. Most contributing to the model was the mean monthly PET (potential evapotranspiration) of the coldest quarter, continentality and annual PET. In terms of the Most Limiting Factor, in Ukraine continentality is crucial throughout the majority of the country.