With the recent increase in wild boar (Sus scrofa L.) populations in northern parts of Switzerland, reports of wild boar grubbing events in forests and agricultural fields became much more frequent. While the economical damage of these events has been discussed intensively, little attention has been given on how wild boar grubbing affects forest ecosystem processes. However, grubbing by wild boars incorporates the forest floor into the mineral soil, which could significantly alter forest soil properties (physical, chemical and biological). This could not only affect carbon (C) and nutrient fluxes and stores, but also forest productivity and stand regeneration. The objectives of this study are to assess how wild boar grubbing effects soil physical (soil bulk density, pH), chemical and biological (microbial biomass, activity and composition) properties in deciduous forest stands, with a special emphasis on patterns and processes related to the C and nitrogen cycle. Preliminary data show that boar grubbing leads to lower bulk density, and mineral soil C content, but higher microbial diversity and biomass.