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

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.

[Trends of angiosperm genome evolution].

Direction of evolutionary variability of parameters of genome size and structurally functional activity of plants on life forms groups and angiosperms taxa are analyzed. It is shown that, in the Cretaceous-Cenozoic, their nuclear genome tended to increase. Functional genome efficiency (intensity of functions per 1 pg of DNA) decreased from as much as possible high at trees and lianas of rain and monsoonal forests of the Paleogene to minimum at shrubs, perennial and annual grasses of meadow-steppe vegetation which had appeared in the neogene. Important for the vegetation environmental changes in temperature, humidity and CO2 concentration in an adverse direction are discussed as the cause of evolutionary genome size growth and decrease in its functional efficiency. Price for phylogenetic adaptogenesis of angiosperms to the step Cenozoic climate cooling was 4-fold and more genome growth.