The Turkey oak high forests in the Molise region (central Italy). Analysis of past silvicultural system and current management choices.

Aim of the work is to provide further knowledge on the silvicultural system applied to Quercus cerris hight forests in the Molise Region (Central Italy). An historical analysis, based on a number of forest management plans applied since 1940 referred to 19 municipalities and on other historical documents, is provided in the paper. Forest management has been traditionally applied in the Molise Region and therefore is at now possible to reconstruct in detail the management of the forests of Molise Region. The historical study has been integrated with the analysis of a chronosequence including four steps of stand development in a Turkey oak stand: the regeneration phase (1-2 yrs) - the unthinned young stand (46 yrs) - the unthinned adult stand (aged 60 to 100) - the mature stand (126 yrs). Mensurational surveys were carried out at each phase in order to characterize both stand structure and derive information on the silvicultural practices applied in the past, but not documented in the available papers. The stand age was determined by tree coring and count of annual rings. At the beginning of the last century, the silvicultural system to be applied in oak high forests wasn’t strictly defined and a particular kind of selection cutting was carried out. It was named taglio a salto per sezioni i.e. “compartment selection cutting”, partly leading back to a real selection cutting, partly to a shelterwood system. The use of the reported silvicultural system gave rise to irregular forest structures and led to management problems well-described in the management plans at the end of 1940s. Another consequence of the applied practices was the absence or the inadequate natural regeneration establishment. The contemporary unregulated practice of grazing the forest floor contributed to the unsuccessful regeneration and made the situation worse. The presence of an understorey layer made up by sproutings from Carpinus betulus stools clearcutting, was a further hindrance to the establishment of natural oak regeneration. In the fifties, the rate of forest management increased as a consequence of the coming up economic concern in sleeper production. The silvicultural shelterwood system was therefore codified. The system resulted to be more effective and adopted up to the present time. The traditional shelterwood system was based on a 90 yrs rotation length, three thinnings performed from the age of 25 up to 75, time of the seed cutting with a release of 90 trees per hectare. In the seventies, following the much more reduced and even null concern in wood production from oak high forests, practices into the same forests were suspended or postponed. At now, the renewed concern for fuelwood production, the only assortment marketable, as well as the increased attention paid to the multifunctional role of these forests, made again actual the problem of oak high forest management. The effectiveness of shelterwood system is the main outcome of the documental analysis performed. The study of the Carovilli’s chronosequence confirmed the close link between the current stand structures and the prescribed rules adopted in the past, in accordance with the management plans. The experimental trials in progress are now focused at defining an improvement of the shelterwood system practice as for the following issues: reduction of cutting areas; establishment of a more complex structural mosaic at neighbouring forest patches, setting up of a consistent release of seed trees i.e. number and dendrotypes to be selected at the purpose, with a special care to the crown cover to the forest floor, effective control of the understorey development due to the resprouting of Carpinus betulus stools, to enhance the establishment of oak natural regeneration