Hydrological Effects on Below Ground Processes in Temperate and Mediterranean Forests

Soil moisture availabilities in European forest ecosystems are varying within the seasonal cycle. Under climate warming, altered precipitation patterns as well as increased temperatures are predicted to result in more frequent or prolonged summer droughts and more severe floods. This review addresses the impact of soil water deficit or excess on soil processes, mycorrhizal symbionts and woody root systems. While we have collected several lines of evidence for adaptive physiological, anatomical and morphological mechanism of fine roots on a single species level, consequences of those changes on the competitive ability and thus the composition of future European forest are hardly known. Thus, future studies are suggested to address the impacts of altered resource availabilities on competitive abilities above and below ground.