Response Of Tree Ring To Climate Change Of Different Provenances Of Cunninghamia Lanceolata

Cunninghamia lanceolata are widely distributed in the climatic region of Subtropical mountain,northern part of Tropics and southern part of warm temperate zone in 18 provinces throughout our country.Currently,under the background of the global climate change,the study of responses of provenances of Cunninghamia lanceolata to climate is still blank at home and abroad.In this research,responses of seven tree ring indexes such as the whole tree ring width,the earlywood width,the latewood width,earlywood density,latewood density,min.density and max.density of fifty-two provenances of Cunninghamia lanceolata to the mean temperature and the total precipitation of months from the July of the previous year to the September of the current year were studied by using tree-ring method.In addition,responses of three tree ring width indexes such as the whole tree ring width,the earlywood width and the latewood width to of fifty-two provenances of Cunninghamia lanceolata to five interannual climatic factors such as annual precipitation,annual mean temperature,the maximum annual temperature,the minimum annual temperature and annual heat moisture index were also researched.Response functions between tree ring width indexes and the main climatic factors were impulsed as well as the growth of different provenances of Cunninghamia lanceolata under the background of the climate change was predicted to provide the basis to select appropriate provenance in the process of afforestation.The main conclusions were as follows:(1)For most of the provenances,correlations between the whole tree ring width,the earlywood width,the latewood width and the mean temperature of July of the previous year as well as August of the current year were strongly negative,correlations between max.density and the total precipitation of April of the current year were strongly negative.Responses of the whole tree ring width,the earlywood width and the latewood width to the annual mean temperature and the maximum annual temperature were the most sensitive among five interannual climatic factors.(2)The mean temperature of July of the previous year and August of the current year explained 38.3% of the total variation in the whole tree ring width from the response function between the whole tree ring width and the mean temperature of July of the previous year as well as August of the current year,among which the mean temperature of July of the previous year and August of the current year explained 53.69% of the total variation in the whole tree ring width from provenance of jianghua,Hunan province.The mean temperature of August of the current year explained 20.2% of the total variation in the whole tree ring width as well as the mean temperature of July of the previous year explained 12.3% of the total variation in the whole tree ring width,which suggested that the mean temperature of August of the current year influenced the growth of the whole tree ring width more than the mean temperature of July of the previous year.The annual mean temperature explained 6.5% of the total variation in the whole tree ring width from the response functions between the whole tree ring width and the annual mean temperature,among which the annual mean temperature explained 24.8% of the total variation in the whole tree ring width from provenance of pingbian,Yunnan province.The maximum annual temperature explained 13.1% of the total variation in the whole tree ring width from the response functions between the whole tree ring width and the maximum annual temperature,among which the maximum annual temperature explained 29.7% of the total variation in the whole tree ring width from provenance of hexian,Guangxi province,which suggested that the maximum annual temperature influenced the growth of the whole tree ring width more than the annual mean temperature.Besides,response function between the whole tree ring width and the interannual climatic factors explained more than response function between the whole tree ring width and the month climatic factors.(3)Climate tendency rate was calculated that the annual mean temperature of the test site will rise 3℃ in 110 years,during which the annual mean temperature will rise 1℃ by 2051,2℃ by 2084 and 3℃ by 2116.With the response function between the whole tree ring width and the mean temperature of July of the previous year as well as August of the current year,it predicted that the whole tree ring width from provenances of suichuan,shuangpai,guangning,jianghua,chuxiong and tonggu,bobai,ziyuan,gulan,anhua,sanjiang,changning,jinping,wuping and luotian were larger and were less influenced by the rise of temperature,so these provenances were selected in the process of afforestation to adapt to climate change.