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LABORATORY FOR BIOCENOLOGY
MAIN GOALS AND TASKS
The main directions of basic research of the Department of Biological Sciences of the RAS (being developed in the Lab):
The research activity of the V.N. Sukachevĺ Laboratory for Biogeocenology and Historical Ecology can be divided into two main areas: the studies in the field of general biogeocenology and in the field of historical ecology.
In the field of biogeocenology the main attention was paid to the study of the spatial structure of forest biogeocenoses, spatial and temporal variability of the energy, water and carbon dioxide fluxes in different types of ecosystems of the boreal forest zone, stability of forest ecosystems and prediction of their possible future changes. These studies were carried out using field measurements, remote sensing data, aircraft measurements, and the process-based mathematical models of different scales and levels of complexity.
The different methods allow to describe the response of the forest ecosystems to changes of environmental conditions in different temporal scales from high (with a time step from one minute to 24 hours), and middle frequencies (month, season, year) to low (from one year to 100 years) and ultra-low frequencies (from 500 years to 15000 years). Depending on temporal scale, the following methods were applied: ecophysiological methods (solar radiation absorption by leaves, trees and canopy, stomatal regulation of water and Đ╬2 exchange between leaves and ambient air, tree water uptake and transpiration, daily and seasonal dynamics of net photosynthesis of leaves and trees, CO2 and H2O exchange at the levels of the tree crown, forest stand and entire ecosystem), forest taxation methods allowing the estimation of the dynamics of forest growth during 100-year period, and also paleoreconstructions of land-use and vegetation changes during the last 15000 years using pollen analysis.
The results of long-term continuous field measurements of Đ╬2 and water vapor fluxes using the eddy covariance method in spruce forest ecosystems of the Central Forest State Biosphere Reserve (zone of Southern European taiga) during the period from 1998 to 2008 allowed to confirm the hypothesis that the boreal spruce forests of the Southern European taiga are the sources of Đ╬2 into the atmosphere. It was shown that the carbon balance of spruce forests during summer periods in the area is very stable and doesnĺt significantly change in long-term perspectives. For the estimation of the possible influence of future climatic changes on carbonic and water balance of boreal forests, mathematical models for energy, water and CO2 exchange between non-uniform forest landscapes and the atmosphere on regional and local scales were also developed and applied.
Using results of multiple field studies, databases of the FAO and the Institute for System Research (Vienna, Austria), literature data (about 5750 descriptions) as well as mean monthly climatic data, the world map of carbon pools in the soils with grid cell resolution about 1×1° was created. Carbon storage was estimated by the step by step discriminant analysis in which the carbon storages measured in the field were used as a dependent variable, and climatic variables were used as independent ones. The total amount of carbon stored in the Earth soils was estimated as about 1.35×1012 C tons. The aggregated ecological and climatological analysis of the data allows the finding of the areas with maximal instability of vegetation cover and high sensitivity to the present climatic conditions. A working hypothesis assuming that the regions of maximal instability are characterized by high risk of the rapid (sometimes catastrophic) structural readjustments in biogeocenoses themselves and in their components (first of all in vegetation and animal populations) has been suggested as well.
On the basis of collected and processed palynological data for test regions on the territory of Eastern Europe, several map sets for taxons of Pinus, Betula, Alnus, Picea, Quercus, Ulmus, Tilia, Carpinis, Acer, Fraxinus, Fagus, Corylus for the last 15000 years with 500-years time step were created. On the taxon maps the stady-state ranges as well as ranges with a high probability of regressive and progressive changes were shown.