Acknowledgements
This research was partly funded by EEA grants of the project BG 0031 EEA ‘State and prospects of the Castanea sativa population in Belasitsa Mountain: Climate change adaptation, maintenance of biodiversity and sustainable ecosystem management’. Fieldwork was assisted by colleagues from the Forest Research Institute in Sofia and the Forest State Farm in the town of Petrich. The authors are grateful to T. Denk, Stockholm, and an anonymous reviewer, who provided useful comments and suggestions to improve the manuscript.