Climate Significance Of The Tree Ring Width Chronology And The Stable Carbon Isotope Series Of Pinus Tabulaeformis In Yishan Mountain, Shandong Province

Tree ring method has been widely used in the field of global climate change due to accuratecross-dating, good continuity, high resolution and high sensitivity to environmental change.Some academicians have already studied the climate change in the dry area of west and northChina by using tree rings. However, the similar study is relatively lacking in east China withwarm and wet character. Taking Yishan Mountain as the area of case study, we establish the treering width standard chronology and analysis the relationship between the tree ring width and theclimate factor by using the tree ring width andδ13C as researching index. We analysis the highfrequency part of tree ringδ13C and discuss the environmental significance of tree-ring stablecarbon isotope ratio (δ13C). Contents and results are as follows:1）The tree ring width standard chronology can reflect the growth character of trees indiffent circumstances and contain amounts of climate information while removing the growthtrend. The results showed that the pine tree ring width chronology had significant negativecorrelations with the mean temperature and the mean maximum temperature in the current yearMay(P＜0.05), and significant negative correlations were observed between the pine tree ringwidth chronology and the mean temperature and the mean maximum temperature in the currentJune(P＜0.01). The precipitation in the current July had a significant positive correlation withthe growth of pine tree(P＜0.05). The tree ring width chronology had significant positivecorrelations with the mean relative humidity in the current year May-June(P＜0.05). Besides,significant positive correlations were observed between the pine tree ring width chronology andthe mean relative humidity in the current year August-October(P＜0.01). Our study indicates thatmore precipitation and lower temperature can promote the tree growth.2）Holocelluloseδ13C series have a difference with all woodδ13C series. Owing to differentgrowth microenvironment, significant correlations were observed between the threeholocelluloseδ13C series. However, only holocelluloseδ13C series Ⅱ have significantcorrelations with the all wood series.3) The high frequency part of tree ringδ13C have significant correlations with the climatefactors after removed the low frequency trend. Generally positive correlations were observedbetween the tree ring△δ13C series and temperature, meanwhile, the precipitation and atmospheric humidity have negative correlations with the tree ring△δ13C series. Thetemperature and precipitation have better correlations with all wood△δ13C series thanholocellulose, therefore, we re-establish climate factors by using all wood△δ13C series.4) Multivariate regression analysis showed that the mean temperature in current April andthe mean relative humidity in current July can explain amounts of the tree ring all wood△δ13C series. Therefore, as researching index the mean temperature in current April were used toreconstruct the mean temperature in April from1860to2011. Moreover, A high fitting value wasobserved between the measured and reconstructed values. Our study indicates that the stablecarbon isotope values of Pinus Tabulaeformis in Yishan Mountainas can be used as the proxiesindicator of some climate and provide information for climate studies.