Land abandonment and/or agricultural intensification are the most probable scenarios which could be expected for remote mountainous areas in Eastern Europe. Both of them can be a threat to the situation existing in the rural areas of the Ukrainian Carpathians where a high degree of connectivity between farming activities and the ecosystem still exists. In the paper we argue that in this area certain agricultural practices are more conducive to biodiversity than others. Therefore we aim at building an economic-ecological model to evaluate the environmental efficiency of farming performance in this area with special consideration of such positive externality as biodiversity. The DEA (Data Envelopment Analysis) is considered as a suitable method for this evaluation and for identification of the farming management patterns which are most efficient from economic and environmental perspectives. The data from socioeconomic and geo-botanic surveys conducted in the Ukrainian Carpathians were used to show how the method can be applied to evaluate the farming efficiency at the research sites. This paper is a contribution to the research on the influence of traditional farming on biodiversity and a trial to analyse economic and environmental performance of farming practices which produce such positive externality as biodiversity.