文摘
The southern part of northeast China has experienced a marked warming and drying climate. We provide dendrochronological evidence for atmospheric CO<sub>2sub> fertilization and the impacts of warming on Chinese pine (Pinus tabulaeformis) growth. The results of this study show that increased temperature has a negative effect on pine growth during a major part of the growing season and a weakly positive effects on growth during the remaining portion of the year. The monthly temperatures explain ca. 20?% of the total variance in the annual radial growth of Chinese pine from 1901 to 2009. An increase of approximately 3-?°C is the maximum that Chinese pine can tolerate in this region with an annual rainfall of 500-00?mm. Our results suggest a that there is a proportional response to warming only up to a maximum of 1 °C warming, and indicate the complexitiesof succession in forest ecosystems in terms of adaptation and evolution in local pine populations under a rapid warming condition. In addition, increasing atmospheric CO<sub>2sub> concentrations have a positive effect on tree growth. This effect can be detected with conventional dendrochronological methods.