Responses of Pinus sylvestris var.mongolica tree ring width to climate factors at different elevations in the northern Greater Khingan Mountains
As an important environmental factor,elevation has a profound influence on the distribution,species composition,growth rate,and physiological characteristics of plants.To investigate the differential response of tree ring width of Pinus sylvestris var.mongolica at different altitudes in the northern part of the northern Greater Khingan Mountains to climate factors,using tree core samples from five elevation sites of P.sylvestris var.mongolica in the northern part of the Greater Khingan Mountains,we established tree-ring width chronologies.By analyzing the radial growth characteristics of the five elevation sites and their correlation with climate factors,we explored the differences and stability of the tree growth-climate relationships at different elevations.The results showed that the tree-ring width chronology from the middle to high elevation site(1150m)contained more climate information compared to other elevations.Correlation analysis between tree-ring width chronologies and climate factors revealed that the high elevation site showed a weak response to temperature,only significantly correlated with the temperature of the previous October and the current September.The middle-high and middle elevation sites of P.sylvestris var.mongolica exhibited a significant positive correlation with temperature during the growing season(April to September and May to August,respectively).Both middle-low and low elevation P.sylvestris var.mongolica were suppressed by drought stress,showed significant negative correlations with precipitation in June,and significant positive correlations with temperature in April and June.Moreover,they demonstrated highly significant positive correlations with the Palmer Drought Severity Index(PDSI)from the previous October to the current September.After temperature abrupt changes,the growth trend of high,middle-high,and middle elevation sites significantly increased,while the growth trend of middle-low and low elevation sites decreased.The correlation results showed that the average minimum temperature in May of the year was the main reason for the increase in tree-ring width at high,medium-high,and medium elevations.Moving correlation analysis indicated that the sensitivity of high and low elevation sites to climate factors decreased,while the sensitivity of middle-high and middle elevation sites to temperature increased.However,the sensitivity of the middle elevation site to PDSI decreased,and the sensitivity of middle-low elevation site to precipitation and PDSI decreased.This study revealed the complex relationship between tree-ring width and climate factors at different elevations of P.sylvestris var.mongolica in the northern part of the Greater Khingan Mountains,providing scientific basis for assessing the adaptability of this species to future climate change.
Pinus sylvestris var.mongolicatree ringsthe Greater Khingan Mountainsclimatic factorabrupt temperature change
万方数据
维普
