Vladimir Andreevich Usoltsev, Seyed Omid Reza Shobairi*, Ivan Stepanovich Tsepordey and Viktor Petrovich Chasovskikh
Based on the generated database of 413 sample plots with definitions of stand biomass of the genus Populus spp. in Eurasia, from France to Japan and southern China, statistically significant changes in the structure of forest stand biomass were found with shifts in winter temperatures and average annual precipitation. When analyzing the reaction of the structure of the biomass of the genus Populus to temperature and precipitation in their transcontinental gradients, the clearly expressed positive relationship of all components of the biomass with the temperature of January is visible. Their relationship with precipitation is less clear: in warm climate zones, when precipitation increases, the biomass of all wood components decreases intensively, and in cold climate zones, this decrease is less pronounced. The foliage biomass does not increase when precipitation decreases, as is typical for wood components, but decreases. This can be explained by the specifics of the functioning of the assimilation apparatus, namely, its transpiration activity, when warming and the corresponding increase in transpiration requires an increase in the influx of assimilates into the foliage, and the desiccation of the climate reduces this influx of assimilates. Perhaps this phenomenon demonstrates the future scenario of acclimatization of trees to the ongoing warming and changes in the water balance of territories. The results obtained can be useful in the management of biosphere functions of forests, which is important in the implementation of climate stabilization measures, as well as in the validation of the results of simulation experiments to assess the carbon-deposition capacity of forests.
