Soil Disturbance Induced by Silvicultural Treatment in Chestnut (Castanea sativa Mill.) Coppice and Post-Disturbance Recovery

Abstract

Chestnut forests represent an important environmental and landscape element in Europe, especially in the hill regions of southern Europe. In Italy, the total surface amount of chestnut forests is slightly expanded with 788,408 hectares, but orchards show a dramatic reduction (147,586 hectares or 20% of the total) and timber-producing stands a comparable expansion (605,888 hectares or 80%). The coppice management actually applied is considered one of the oldest forms of sustainable forest management. Over the years, coppice highlighted its versatility, resilience and multifunctionality. In this management system, in consideration of the “frequent” cutting cycles, special attention must be paid to forestry operations, because tree damage and soil compaction can trigger fungal disease and soil erosion. Frequent and repeated machine traffic increases the risk for soil degradation derived from compaction, topsoil removal and general disturbance. This study covered different forest areas and mechanization levels, in order to evaluate if the extent, type and severity of soil disturbance changed with site characteristics and logging technique. Furthermore, the study sought to obtain a better knowledge about the recovery time required for restoring the original soil properties after a disturbance has occurred. The findings showed that physical, chemical, and biological soil features were only partially disturbed by the coppicing and again that a high level of specialized mechanization does not generate heavier soil impact compared with the smaller and lighter machines deployed under the traditional and intermediate mechanization scenarios. Soil recovery in the impacted areas is already measurable one year after harvest and may be complete within the eight year—that is halfway through the standard rotation applied in the region to chestnut coppice.