Foliage biomass of the genera Picea spp. and Quercus spp. in winter temperature and annual precipitation gradients: Inter-genera paradox in the forests of Eurasia

• Published in: Computational ecology and software 2022-09, Vol.12 (3), p.123-140
• Main Author: Usoltsev, V A
• Format: Article
• Language: English
• Subjects: Annual precipitation; Atmospheric models; Biomass; biomass equations; Carbon dioxide; Climate change; Cold; Cold regions; Comparative analysis; Disturbance; Foliage; foliage biomass; foliage efficiency; Forest biomass; Forest ecosystems; Forests; hydrothermal gradients; mean january temperature; Moisture effects; Natural disturbance; Oak; Paradoxes; Photosynthesis; Picea; Plant communities; Plant populations; Precipitation; Quercus; regression models; Respiration; Terrestrial ecosystems; Winter
• ISSN: 2220-721X

Current climate change make it increasingly important to assess the response of forest cover biomass to this change, which in turn determines the possibility of climate stabilization by reducing atmospheric CO2. Climate change projections can been linked to significant changes in water deficits and natural disturbance regimes in forest ecosystems across many parts of the world.Since the carbon-deposing potential of a plant community is determined by the biomass of assimilating organs, we focused in this article on comparative analysis of foliage biomass in the dark-coniferous genus Picea spp. and of leaved genus Quercus spp. in gradients of annual precipitation and winter temperature on the territory of Eurasia. The database for modelling involves 870 and 570 sample plots for spruce and oak correspondingly. When studying changes in the biomass of spruce and oak foliage in the hydrothermal gradients of Eurasia, we obtained statistically reliable, but surprising and paradoxical results. When the temperature increases by 1oC, the most increase in spruce foliage biomass occurs in cold regions with insufficient moisture supply, while oak leaf biomass, on the contrary, has the largest percentage of its decrease. In cold regions, as the transition from dry conditions to wet ones, the percentage of foliage mass in spruce decreases, and in oak increases. When the precipitation increases by 100 mm, there is the opposite patterns for spruce and oak: in warm regions, spruce has a decrease in the percentage of foliage mass, and oak, on the contrary, its increase. In the cold regions, these patterns change to the opposite: the spruce negative percentage changes to positive, and the oak positive percentage changes to negative. This phenomenon seems to be related to the positive ratio of photosynthesis and respiration in the spruce during the winter period when the oak does not have photosynthesis, but only respiration. It seems to be related to the fundamental difference between the winter physiology of evergreen and deciduous species, namely the ability of the former to assimilate atmospheric carbon dioxide and prolong the assimilation process beyond the vegetation period, which is usual for deciduous species. The development of such models for the main forest-forming species of Eurasia allow us to predict changes in the foliage productivity of the forest cover of Eurasia in relation to climate change.