Abstract
The past century witnessed a dramatic increase in deer abundance in North America and Western Europe that triggered profound changes in the structure of temperate forests. If these changes are today well characterised, the effects of abundant deer belowground in these forests remain unclear. Deer can interfere with the soil through waste deposition, trampling, and reduction of litter quantity and quality by preferential browsing of palatable plants. What are the consequences of these interactions for the soil? To answer this question, we studied the soil response to the colonisation and culling of Sitka black-tailed deer (Odocoileus hemionus sitkensis) in the forests of Haida Gwaii. We found that deer slowed-down litter decomposition by reducing litter quality. They also modified microbial community structure and ability in decomposing carbon via soil trampling. Most of these effects became only apparent in the long term, hence questioning the results obtained through short term studies.