Impact of cattle density on the structure and natural regeneration of a turkey oak stand on an agrosilvopastoral farm in central Italy

On an agrosilvopastoral farm in central Italy where Maremmana cattle graze in Turkey oak forests, we evaluated the impact of different livestock densities on stand structure, tree diversity and natural regeneration in four types of grazed areas based on the grazing regime adopted: calf-grazed, high-intensity-grazed, low-intensity-grazed, ungrazed control. For each area, we set up three permanent circular plots (radius of 15 m) to survey the structural and dasometric characteristics of the overstorey, understorey, and regeneration layer. The results showed that grazing negatively affected the complexity of the forest structure and its potential to regenerate and maintain a high level of biodiversity. The differences in stand structure observed between the grazing areas were closely related to livestock density. The most sensitive components of the system were the understorey and the regeneration layers. Contrarily, the current grazing management did not affect the dominant tree structure or its composition. Our findings identified medium-term monitoring and regeneration management as the two significant aspects to consider when assessing sustainable livestock. New forests can be established by excluding grazing for about 20–25 years.