Wild boar (Sus scrofa) damages to mountain grassland. A case study in the Belluno province, eastern Italian Alps

Abstract

Five alpine pastures (34±14ha) of the Belluno province, patchily damaged by wild boar, were chosen to investigate on main environmental parameters that might influence the rooting sites selection. Eighty damage sites were examined. For each damage surrounding type of grassland and distance from woodland were recorded and mapped using a G.I.S. software. Proportional availability (% of total pasture surface) of grassland types (rough grass, rich grass, degraded, shrubs and trees) and classes of distance from woodland (<30m, 30-60m, 60-120m, >120m), and the respective use (% of total damage events) were estimated and compared with Chi-square test. A selection index was calculated as use/availability and Bonferroni confidence intervals (95%) were used to test significance. Degraded pastures and areas closer to woodland blocks were preferred. A vegetational analysis inside and outside the damaged areas showed a reduction in frequency of species producing bulbs and rhizomes, and in Poaceae as respect to other families of lower forage value. Future studies should investigate the role of different root forms, and invertebrate richness, on rooting site selection. Longer term studies are also needed to better define the evolution of pasture botanical composition of damaged areas.