Anyone that has ever walked through an open oak forest in early summer, hearing the birds’ cheerful song while catching a glimpse of the first morning sun, knows what a peaceful and satisfying feeling it brings you. The magnificence of the old oaks with their wriggling branches and enormous diameter is stunning, and the realization that many of these trees are hundreds and hundreds of years old gives you a feeling of respect. But of course, the trees are not growing there merely for our pleasure. If we look back in time, old growth deciduous forests were a common element in many parts of Europe. Changes in land use and management strategies during the last century have, however, reduced these areas to a small fraction of its original distribution. Therefore, it is of particular importance that we manage and protect the few areas that are still left intact, in order to maintain a high biodiversity. However, a large amount of oak declines have been recorded in many parts of Europe during the last three decades. The declines are causing a weakening of the oaks and frequently result in a premature death of the trees. Although a fair amount of research has been done in the area, the causes of oak declines are still poorly understood. Therefore, my work has focused on analysing possible factors that increase the risk of oak mortality. To do this, I have studied both environmental variables in the close surroundings of the trees and core samples taken from dead and living oaks. If you are interested in the results and a more detailed description of the study, feel free to check out the links found in the menu to the left.