Effects of wild boar (Sus scrofa) grazing on soil properties in Mediterranean environment

Two sites (Asciano and Castelfalfi) were selected in Tuscany (central-west Italy) in order to study the effects of wild boar activities (rooting and trampling) at two different densities and on the organic matter quality and functionality in soil ecosystems. In each site, two study areas with different vegetation (woodland (W) and olive tree grove (O)) were identified to evaluate the influence of vegetal cover on soil properties. Physical, chemical, biological and chemico-structural (pyrolysis–gas chromatography) analysis were combined to assess the evolution of soil characteristics. In the low boar density site (Asciano) soil organic matter quality and biological activity resulted positively affected by rooting and trampling activity (higher value of total organic carbon, total nitrogen, ATP and biomass carbon in soil grazed), while the high wild boar density (Castelfalfi) was responsible for a higher soil degradation as suggested by the lower value of chemico-physical and biological parameters. The effect of wild boar activity on soil depends also on the type of vegetation, in fact, woodland vegetation, with a greater contribution in organic matter, seemed to be more efficient in the protection of soil against degradation with respect to olive cover, also in Castelfalfi site, showing an improvement in the physical and biological soil properties.