Climate change in the forests of northern Germany
A research team from the University of Göttingen has now been able to show that the European beech is suffering from increasing drought stress in summer in northern Germany as well. This climate stress is particularly pronounced at warmer sites, when there is a higher density of these trees together, and on very sandy soils. The results have been published in the journal Global Change Biology. In their study, the researchers specifically selected a wide range of sites ranging from wet to very dry, because even in northern Germany there are very dry beech forests. The scientists took numerous wood samples at all these sites to measure the tree rings in the tree trunks. “This allows us to look back over many decades and reconstruct tree growth in the past,” explains Dr Robert Weigel, a postdoctoral researcher in Plant Ecology and Ecosystem Research at the University of Göttingen. These data were combined with those from climate stations, to derive the relationship between climate and growth of the trees. The investigations revealed that drought and heat in June, the main month of growth for beech trees, are the most important climate factors influencing how much the trunk will grow across all the locations studied, with the negative effects being stronger in drier locations.