摘要:Effects of possible climatic and vegetation changes on
H2O and
CO2 fluxes in boreal forest ecosystems of the central part of European Russia were quantified
using modeling and experimental data. The future pattern of climatic conditions for the
period up to 2100 was derived using the global climatic model ECHAM5 (Roeckner et al 2003 The Atmospheric General Circulation Model ECHAM 5. PART I: Model
Description, Report 349 (Hamburg: Max-Planck Institute for Meteorology) p 127) with the
A1B emission scenario. The possible trends of future vegetation changes were obtained by
reconstructions of vegetation cover and paleoclimatic conditions in the Late Pleistocene
and Holocene, as provided from pollen and plant macrofossil analysis of profiles in the
Central Forest State Natural Biosphere Reserve (CFSNBR). Applying the method of
paleoanalogues demonstrates that increasing the mean annual temperature, even by 1–2 °C, could result in reducing the proportion of spruce in boreal forest stands by up to 40%.
Modeling experiments, carried out using a process-based Mixfor-SVAT model, show that
the expected future climatic and vegetation changes lead to a significant increase of net
ecosystem exchange (NEE) and gross primary productivity (GPP) of the boreal forests.
Despite the expected warming and moistening of the climate, the modeling experiments
indicate a relatively weak increase of annual evapotranspiration (ET) and even a reduction
of transpiration (TR) rates of forest ecosystems compared to present conditions.