Quantification and spatial variability of rooted-soil reinforcement in managed and abandoned chestnut coppice forests

Sweet chestnut dominates the Italian mountainous territories, and in particular the lowand mid- altitude areas, where it played a fundamental role in mountain economy and in people subsistence. In such areas, sweet chestnut stands have always been a source for woody material, and have been traditionally managed by coppicing in a short rotation. Due to socio-economical changes occurred in the last half century, the sweet chestnut stands have been largely abandoned. Most of these stands are now over-aged and stools uprooting events are very common, being a great concern among forest managers, especially in areas prone to shallow landslides and debris flows. To investigate the effects of chestnut abandonment on slope stability, this study focused on the spatial variability of root reinforcement in two different chestnut stands: (i) abandoned, and (ii) managed. Additional root reinforcement was estimated combining a root distribution and a root reinforcement model, both calibrated with field data. As expected, results emphasized that external factors, such as the age of plants, do not affect the mechanical properties of roots, whereas there is a significant difference in terms of root density and rooting depth according to the forest management.