This site is located on the territory of Belasitsa Nature Park. The southwest part of Bulgaria where the Belasitsa mountain is situated falls into the European Broadleaf Forest Region, Macedonian Province. The chestnut belt has area of 2592 ha and is situated between 250 m and 900 m altitude. The forest has complex spatial structure and distorted age structure. The mean age of trees is 95 years but individuals aging 350 years are present, with diameter 2,5 m and height up to 18 m. In the community a tendency for substitution of the chestnut by other tree species is present. The climate is characterized by rainy winter and hot and dry summer. The vegetation period is near 220 days. Data on climate are available from the near by site in the town of Petrich. There are 3 sites with dispositives for meteorological, hydrological and hydrobiological measurements and 3 Forest permanent sample plots.