Forest Response to Climate Warming and Wildfires in Southern Siberia: Evidence of Suppressed Forest Productivity Due to Wildfires, Energy and Water Limitations

The regulation of CO2 by sequestering carbon in soils and vegetation is crucial for forests, which are threatened by global warming and forest fires. As boreal forests warm more rapidly, extreme disturbances like droughts and wildfires are expected to increase by the end of the century. This thesis aimed to better understand patterns of boreal forest growth in southern Siberia in response to climate warming and forest fires using remotely sensed and in situ data. The study found that 80% of unburned forests experienced a decline in productivity due to anomalously high temperatures and reduced water availability. Evergreen stands experienced the greatest productivity declines, indicating an expansion of deciduous stands over evergreens. Forest fires can suppress forest productivity, and the growth dynamics of Scots pine stands with different ages and fire histories were studied at six different sites. The study also found significant post-fire trends in post-fire biomass, with significant structural changes 10 years post-fire. The study also explored the potential use of in-situ data, such as tree density, fire characteristics, and climatic conditions, to predict post-fire biomass accumulation. Biomass values of up to 11073 g/m2 were found, with poorly regrowing sites having the lowest biomass.