The experimental measurements of CO2 and H2O in disc tree-rings of some coniferous from regions with different climates have been obtained, the results were compared with the tree-ring widths, some conclusions were made about climatic response of annual CO2 and H2O distributions. The hypothesis was put forward that the appearance of long-period cyclicities in annual CO2 tree-ring distribution is a tree's response to the environmental change.
СО2, cyclicity, tree rings, laser photoacoustic gas analysis, climatic response