Climate from dendrochronology: latest developments and results

This review deals with the latest developments in dendroclimatology focused on climate reconstruction. It presents results from research carried out during the period 1992–2001, when both the geographical and chronological extension of tree-ring data were greatly improved. Research projects are presently being carried out in nearly all the main forest land areas of the Subarctic and Subantarctic zones, outside the traditional regions of research in North America and Europe, and about 150 tree-ring chronologies over 1000 years in length have been developed. Special attention is paid to data from Southern Europe and the Mediterranean area, where a detailed temperature reconstruction has been completed back to A.D. 970. Research carried out in Italy and France provides useful information on climate change and CO2. The aim of this research consists of evaluating whether in the radial tree growth of recent decades, there might be a part unexplained by climate and due directly to increasing atmospheric CO2 fertilisation. These studies show that many wooden species in various ecosystems show different responses of ring width to increasing atmospheric CO2. Finally, new scenarios of vegetation distribution and carbon sequestering, due both to positive or negative response from the trees, are offered by studies that reconstruct the expected radial growth of trees in situations of atmospheric CO2 doubling.