Can the drought tolerance of European beech be improved by thinning interventions?

Climate change is predicted to intensify summer droughts in Central Europe. In the long term, adaption may be achieved through changes in species and genetic composition of forests. In the short-term, adaptation measure must also reduce drought stress for existing forests. The reduction of stand density through thinning has been identified as a promising means to reduce drought-effects for even-aged stands from several tree genera, mainly coniferous ones.
Despite the fact that the drought-sensitive European beech (Fagus sylvatica) is the naturally predominant and most important broadleaved tree species in Central Europe, knowledge concerning the suitability of thinning to enhance its drought-tolerance is lacking. By the means of dendroecological analysis of stem slices and tree cores from different stands in Southern Germany, we are evaluating potential effects of moderate and heavy thinning interventions on the drought-response in European beech during and after an extreme-drought event. The results support the development of more intensive thinning regimes in Central European beech forests.