[A-CG46] Science in the Arctic Region

[ACG46-P12] Responses of tree radial growth to climate changes in central Siberia deduced from dendro-ecological approach

*Shunsuke Tei¹, Darshana Athukorala¹, Dmitry Schepaschenko^2,3, Liudmila Mukhortova², Sergey Farber², Leonid Krivobokov², Nastassia Sokolova², Ekaterina Tyutkova², Alexsey Martynov², Shin Nagai⁴, Gen Takao¹ (1.Forestry and Forest Products Research Institute, 2.V. N. Sukachev Institute of Forest of the Siberian Branch of the Russian Academy of Sciences, 3.International Institute for Applied Systems Analysis, 4.Japan Agency for Marine-Earth Science and Technology)

Keywords:central Siberia, tree-ring, tree growth, climate change

Tree-ring width indices (RWI) are useful long-term indicators of historical forest productivity due to the frequently observed close relationship of the RWI with forest-level gross primary production (GPP) and/or net ecosystem exchange (NEE). While there have been recent improvements in our understanding of the historical forest productivity and its relationship with climate changes, RWI studies have some regional bias toward Europe and North America. Further efforts to fill the gaps in RWI data/study, such as in Siberia, are required.
In this study, we developed RWI chronologies over the past 80-200 years by using Larch (Larix sibirica Ledeb), Siberian pine (Pinus sibirica Du Tour) and /or Scots pine (Pinus sylvestris L.) trees at two forest sites, each with different annual/summer precipitation, in central Siberia: Baykit (61°37-39 N, 96°41-48 E) and Vanavara (60°23-37 N, 101°39-57 E). The temporal change of RWI and its relationship with climate changes reflected site differences better than tree species differences. At Baykit site, positive correlations with monthly temperatures were dominated both for larch and Siberian pine trees. On the other hands, positive correlations of RWI with monthly precipitations were dominated at Vanavara site, where annual/summer precipitation is lower than at Baykit, probably due to severer water stress. Although the climate factor controlling RWI variability vary among sites, given that almost all significant correlations of RWI for temperature and precipitation were positive for both forest sites, future increase in tree growth may be expected under predicted increases in temperature and precipitation.