[Tree-rings width variability along latitudinal and paleolatitudinal gradients].

Abstract

Processed are 57596 dated series of tree-rings width (TRW ) from the International Tree-ring Data Bank. The results obtained indicate that: 1. The TRW is strongly correlated with tree age. Periods of cambium activity are strictly dependent on the age of the trees. Therefore, there is a strong correlation between TRW and periods of radial growth. It is suggested that synchronization of the periods of radial growth in the first 150 years of trees life with cycles of climatic factors leads to increase in TRW . 2. Satisfactory coincidence between latitudinal profiles of TRW , on the one hand, and climatic and biological indicators, on the other hand, is observed. Latitudinal profile of TRW gets its form under the influence of climate and assimilating mass productivity. 3. Latitudinal change of the TRW in the Cretaceous had a pronounced displacement of a maximum from equator toward 30 °NL. Growth gain of Cretaceous gymnosperms was about twice higher than that of modern trees. Such asymmetry of paleolatitudinal profile of TRW sharply distinguishes it from modern latitudinal profiles that follow climatic parameters.