6:15 PM - 7:30 PM
[ACG30-P03] Response of Siberian larch in Mongolia to environmental variability for the last century
Keywords:Monoglia, Larch, Tree-ring, Carbon isotope ratio, Drought stress
Tree-ring width at Terelj negatively correlated with temperature and positively correlated with precipitation, and carbon isotope ratio positively correlated with temperature and negatively correlated with precipitation of previous and current summer. Especially, tree-ring width shows more clear correlation with precipitation in previous summer than that in current summer, whereas carbon isotope ratio shows more good correlation with precipitation in current summer than that in previous summer. These results suggest that stem growth depends on the moisture condition in previous year, while tree-ring is formed with carbon assimilated in the current year. Siberian larch showed very narrow ring width in recent years (after 1997) with very high carbon isotope ratio at Terelj, suggesting severe drought stress. On the other hand, tree-ring width and carbon isotope ratio in northern forest area did not show clear correlation with climate parameters. This results imply that trees in Tsagaannuur and Hatgal grow under relatively wet condition compared to trend at Terelj. Narrow ring width and high carbon isotope ratio found for Terelj was not observed trees in northern forest area.