[The relationship between environmental change and stable carbon isotopes records from tree-ring in Mt. Helan].

The value of stable carbon isotope in plants is closely correlative with environmental factors. The stable carbon isotope chronology was attained from tree-ring alpha-cellulose in pine(Pinus tabulacformis), Mt. Helan. The relation between delta 13C series and precipitation from January to July was negatively correlative(r = -0.515, alpha = 0.05). And the delta 13C series was positive correlative with the average temperature from June to August(r = 0.427, alpha = 0.05). Also the atmospheric CO2 content relates to the delta 13C series in the tree-ring cellulose. It was easy to find the increasing trend of CO2 composition in the atmosphere from the tree rings. By the relation between the number of sunspot and delta 13C series, the more number sunspot was correlated with higher delta 13C value was found.