Modifiche compositive e strutturali in soprassuoli in evoluzione naturale della riserva M.a.B. di Montedimezzo (Isernia)

Tree species composition and structural dynamics in forest stands under natural evolution in the Montedimezzo M.a.B. reserve. This study is included in an experimental protocol established in 1954 aimed at examining the natural dynamics in mixed broadleaves high forests dominated by Turkey oak (Quercus cerris L.) and beech (Fagus sylvatica L.). Stand development patterns in the last fifteen years are reported. Repeated quantitative and qualitative inventories were carried out in two permanent plots (3 ha each) and in two structural transects (0.2 ha each) located in Collemeluccio-Montedimezzo M.a.B. reserve (Is). The study highlighted, as already observed in 1954, the differences between the two multilayered stands. In the higher elevation beech is the predominant species recording 53% of importance value index (I), followed by Turkey oak (I=25%). In the lower elevation the dominant species is Turkey oak (I=46%), followed by hornbeam (Carpinus betulus L.) (I=28%) and beech (I=12%). The decreased presence of Turkey oak and the increase of beech density are confirmed in each plot over the last fifteen years. Among the other tree species, importance values rise only for silver fir (Abies alba Mill.) (introduced) and holly tree (Ilex aquifolium L.), while hornbeam and hedge maple have been reducing their own presence