Tree-ring climate reconstructions at multi-centennial scale
Abstract
The aim of the planned research is the reconstruction of palaeoclimatic conditions in the northern Alps region. The presented research project constitutes the supplement to the research 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 it aims at the reconstruction of climatic conditions which have existed in the area of Austrian Alps in the period of the last millennia. The research in progress is based on the dendroclimatological method. The scientific work so far resulted in the creation of dendrochronological scale for spruce and larch wood. This chronology ranges from 1526 BC to 2004 AD. The goal of the planned research is broadening the scientific work by the scope of densitometric wood analyses. Wood density analyses are especially valuable source of information during the reconstruction of thermal conditions of the environment. The X-ray densitometry requires a special measurement device and it is very time-consuming method. Therefore an using of wood density analyses is rather rare. But in comparison to the research based on the measurements of annual tree ring width, the density chronologies allow to reconstruct the palaeoclimatic conditions more precise. The identification of air temperature and its changeability in the period of the last hundreds and thousands of years constitutes the fundamental issue with the regard to recognizing the reasons of current climate changes. The intensive dendroclimatic research, which has been carried recently, aims at the reconstruction of environmental conditions in the period of the last few centuries, and sometimes even millennia. It is also used for interpretation of climatic fluctuations observed in the recent years. These fluctuations have been documented by meteorological records. Meteorological data, however, are limited in most of the cases to the last few decades. Dendroclimatic analysis allows to compare the scale of observed climatic changes in the perspective of much longer period of time. The network of dendroclimatic research, which is developing in Europe, enables the recognition of spatial diversification and range of these changes.
keywords densitometry dendrochronology dendroclimatology climate reconstruction climate-growth relationships