2:30 PM - 2:45 PM
[MIS01-04] Effects of deforestation of boreal forests on atmospheric fluxes and weather conditions at the local and regional scales
Keywords:deforestation, boreal forest, clear-cut, eddy covariance, COSMO model, net ecosystem exchange of CO2
Comparisons of the sensible and latent heat fluxes measured at the clear-cut area and in an undisturbed spruce forest stand situated not far away from the clear-cut area showed that the largest differences in sensible heat, H2O and CO2 fluxes between both sites were observed during the first year (2016) after timber harvesting, and were mainly influenced by differences in surface albedo (Mamkin et al 2019). Comparisons of the sensible and latent heat fluxes measured at the clear-cut area and in the spruce forest stand showed that in the undisturbed forest the latent heat fluxes are steadily exceeded the corresponding clear-cut fluxes even in periods with sufficient soil moisture conditions promoting active regeneration and growth of grassy and woody vegetation at the cleared area. Comparisons of the NEE components for the clear-cut and undisturbed spruce forest are revealed significant differences in NEE rates for the first year after forest clearing, and gradual decrease of their disparities in the following years. Whereas the clear-cut area during the first three years after timber harvesting is functioned as a CO2 source for the atmosphere, the CO2 balance of undisturbed mature spruce forest in the period was close to zero (Mamkin et al., 2016, 2019).
All obtained results are well agreed with flux estimations provided by a local 3D turbulent exchange model and the COSMO-Ru-NWR model for regional weather predictions. In particular the numerical experiments provided using the COSMO-Ru-NWR model for several modeling scenarios imitating total deforestation of a large area situated within European southern taiga zone showed that total forest disturbances can result in changes of radiation and energy budgets of the area and consequently in increasing the annual amplitude of the air temperature (decrease of winter temperatures and their growth in summer) and in reducing the precipitation amount in all seasons of the year (projected annual decrease is about 4%) (Olchev et al., 2018).
The results obtained in the present study can be very useful for better understanding the effects of forest disturbances on atmospheric fluxes at land surface - atmosphere interface and estimating their possible influence on regional weather conditions.
References
Mamkin V., Kurbatova J., Avilov V., Mukhartova Yu, Krupenko A., Ivanov D., Levashova N., Olchev A. 2016. Changes in net ecosystem exchange of CO2, latent and sensible heat fluxes in a recently clear-cut spruce forest in western Russia: results from an experimental and modeling analysis. Environmental Research Letters. 11(12). 125012
Mamkin V., Kurbatova J., Avilov V., Ivanov D., Kuricheva O., Varlagin A., Yaseneva I., Olchev A. 2019. Energy and CO2 exchange in an undisturbed spruce forest and clear-cut in the Southern Taiga. Agricultural and Forest Meteorology, 265, P. 252-268
Olchev A.V., Rozinkina I.A., Kuzmina E.V., Nikitin M.A., Rivin G.S. 2018. Influence of forest cover changes on regional weather conditions: estimations using the mesoscale model COSMO. IOP Conf. Series: Earth and Environmental Science, 107, 012105