The Effect of Grazing on Old Oak Forests from Eastern Rhodopes Mountains, Bulgaria

The present study focuses on the old oak forests within the territory of Krumovgrad State Forestry Unit (SFU), located in the central part of the Eastern Rhodopes Mountains. Field measurements were performed in both abandoned and ongoing pens, covered by Quercus petraea and Quercus frainetto dominated forests with ages ranging between 120-130 years. The aim of the study was to identify the consequences of long-term practiced grazing in old oak forests (forest pastures) after their abandonment as well as the perspectives in terms of their preservation, restoration, regeneration and future maintenance. The study confirmed the negative effect of intensive grazing over old oak forests within the territory of SFU Krumovgrad, related with soil exhaustion and erosion, suppression of seeds production/successful regeneration and severe forest degradation. However, it also revealed the preserved valuable genotypes, forest structures and regeneration potential of these forests. Furthermore, it was proved that during the last 20-30 years, since grazing had been abandoned or not intensively practiced, forests' health condition have improved, canopy closure has increased and old stands were able to successfully regenerate on their own. In addition, significant similarities between the characteristics of studied old oak forests and those of old-growth forests were observed. This could reasonably justify some old oak forests' areas within the SFU Krumovgrad managed territory to be protected from commercial logging by declaring them old-growth forests that are part of Natura 2000 network or covering them by the upcoming Forest Stewardship Certification.