Tree-ring climate reconstructions at multi-centennial scale

The aim of the proposed research is the reconstruction of climatic conditions which have existed in the area of Austrian Alps during the period of the last millennia. The planned project will be a part of the ongoing research work which is currently being carried out in dendrochronological laboratory at the University of Natural Resources and Applied Life Sciences BOKU in Vienna. This research has been in progress for the last few years and is based on the dendroclimatological method. The scientific work carried out by BOKU researchers so far resulted in the construction of exceptionally long dendrochronological scale for spruce and larch wood. This chronology ranges from 1526 BC to 2004 AD and creates an excellent material to dendroclimatological study, especially when taking thermal conditions of environment into account. It is due to the high-mountainous character of the area, from which the tree comes from, high similarity of ecological conditions of sites, where the trees had grown and climatic homogeneity, and small territorial range of the area, where the samples were collected. Currently, the research work is carried out to use the constructed chronology in dendroclimatic analysis based on the width of annual growth-rings. It is conducted by the employees of BOKU laboratory in cooperation with the international team of researchers. The goal of the planned research is broadening the scientific work by the scope of densitometric analyses of wood. Wood densitometry is especially valuable source of information during the identification of temperature conditions of the environment. In comparison with the research based on the measurements of annual tree-ring width, the density chronologies allow to determine the palaeotemperatures more precisely. The planned research work will include densitometric measurements of wood, construction of growth- ring density chronology and temperature reconstructions by using dendroclimatological method. Realization of these research is planning to carry out in dendrochronological laboratory at the University of Natural Resources and Applied Life Sciences BOKU in Vienna. BOKU laboratory possess appropriate equipment and measurement device in the form of X-ray densitometer and computer programs necessary to conducting the tree-ring densitomeric research. The dendroclimatological research based on densitometric measurements of wood is precise method which allows to reconstruction the environmental temperatures in long-time perspective. The reconstruction of air temperature and its changeability constitutes the fundamental issue with the regard to recognizing the reasons of current climate change. This process is currently one of the main environmental, economic and social problems on the global scale. The precise reconstruction of past climatic variations offers also the opportunity to forecast the climate changes in the future.