The conversion into high forest of Turkey oak coppice stands: methods, silviculture and perspectives

The goal of this study is to assess the impact of different thinning approaches for coppice conversion into high forest of Turkey oak stands in Italy. The stand structure and the tree/shrub diversity were analyzed in 27 long-term monitoring plots from 7 experimental trials in the Colline Metallifere district (Tuscany, Central Italy) to verify the consistency of the original cultivation goals with the current stand structures. Three different approaches were applied from 1969 onwards: thinning from below, selective thinning, and no-management. Three indexes of specific diversity (Specific Richness, Shannon index and Importance Value) and two indexes of vertical diversity (Vertical Evenness and Coefficient of variation of tree height) were used to analyze and compare the outcome of management practices. The results showed a significantly higher dimensional variability and basal area, and a more complex vertical diversity in control plots and in the plots subject to selective thinning, as compared with plots subject to thinning from below. Tree species richness was high in all plots, independently of the thinning type applied. Based on our results, we suggest Turkey oak-dominated transitory stands to be initially managed by thinning from below, which is easy to be implemented and economically feasible. Selective thinning may be applied later with the aim of promoting sporadic but valuable tree species and increasing tree species diversity.