Response Of Radial Growth Of Pinus Tabulaeformis To Climatic Factors At Different Terrains In Beijing Songshan National Nature Reserve

In order to further understand the relationship between the radial growth of Pinus tabulaeformis and climatic factors in Beijing Songshan,4 plots at different terrains were chosen as study samples.The tree ring chronologies of different terrains were built,and analyzed the relationships between annual growth of Pinus tabulaeformis and climatic factors with analysis methods of correlation analysis and multiple stepwise regression analysis.Main results:(1)The annual average growth of Pinus tabulaeformis is 4.86 mm,4.04 mm and 1.88 mm respectively along the altitude from low to high.The annual average growth of Pinus tabulaeformis that growth in sunny slope is 4.86 mm,higher than the 3.23 mm of Pinus tabulaeformis that growth in shady slope.(2)With the ring of elevation,the average sensitivity of Pinus tabulaeformis chronology increased first and then decreased.The first-order autocorrelation coefficient of Pinus tabulaeformis chronology of shady slope greater than that of sunny slope.(3)Mean temperature of the previous year's months 7,8,9 and the current year's month 5 and the previous year's summer have significantly negative correlations with both of Pinus tabulaeformis growth in the elevation of 948 m and 1073 m(P<0.05),and mean minimum temperature of the last year's months 6,7,8,9 and the current year's months 6,7 and the previous year's and current year's summer and winter also have significantly negative correlations with both of Pinus tabulaeformis growth in the elevation of 948 m and 1073 m(P<0.05);the radial growth of Pinus tabulaeformis that growth in the elevation of 1223m only with the average minimum temperature of June in the current and previous year have significantly negative relationships(P<0.05).(4)The radial growth of Pinus tabulaeformis that growth in sunny slope is negatively correlated with the minimum temperature of current year's month 5 and the average temperature of the last year's month 1(P<0.05);the mean minimum temperature of the last year's month 6 is significantly negative correlated with the radial growth of Pinus tabulaeformis that growth in shady slope(P<0.01).Conclusions:(1)There were significant differences in growth of Pinus tabulaeformis in different terrains.With the rising of elevation,the sensitivity of I radial growth of Pinus tabulaeformis to climate change was first increased and then decreased;the radial growth of Pinus tabulaeformis in the shady slope impacted by the climate change of the last year than that in the sunny slope.(2)The main climatic factor affecting the radial growth of Pinus tabulaeformis is temperature,and the correlation between the radial growth of the radial growth of Pinus tabulaeformis and temperature is different in different terrains.(3)The most suitable linear regression models were established,and the results show that there are differences in key climate factors that impact the radial growth of Pinus tabulaeformis in different terrains.