The buffering effect of the Lake Baikal on climate impact on Pinus sylvestris L. radial growth

Abstract

Large lakes and wetlands control local and regional climate conditions. Since climate controls tree-ring formation, it is expected that air-water-land interaction at Lake Baikal region (southern Siberia), the world's largest freshwater reservoir, could potentially impact tree growth in the surrounding areas. Therefore, we aimed to determine if Lake Baikal influences Pinus sylvestris L. tree-ring growth by modifying climate conditions and alleviating climate limiting factors of tree growth in its neighboring areas. Here we combine dendrochronological measurements with tree growth modeling to evaluate the variability in the climate response of Scots pine annual (tree-ring width) and intra-annual (earlywood and latewood widths) growth and phenology at four sites (two inland and two coastal sites) in the Baikal region for the 1960–2016 period. Tree growth was significantly higher, with longer growing seasons, at the inland sites than at coastal sites. However, an increasingly negative effect of summer temperature and a positive effect of relative humidity on tree-ring growth were observed with increasing distance to the lake. The results suggest that although Lake Baikal's thermal mass lessens the climate control on the tree growth by acting as a thermal and hydric buffer in the downwind coastal sites, other factors than climate might potentially control tree growth in the region. Our results also suggest that the high plasticity of P. sylvestris to thrive in different environmental conditions will probably allow a better adaptation to the projected warmer regional climate than non-drought tolerant species inhabiting the same region.