Climate Response And Early Summer Temperature Reconstruction Of Tree-ring Width In The Altay Region

In this paper，three types of tree-ring width chronologies were developed，byusing3larch ring samples of Xinjiang collected of the southern slope of Altai in2011-2012．It’s found between meteorological data of seven weather stations in theAltay region and Chronology: standardized tree-ring width chronologies on fiveforests’ average upper limit of the forest have the best relevance to the meantemperature of June of seven weather stations, correlation coefficient reaches0.675(0.0000001). By stepwise regression analysis, the equation reconstruction oftemperature is established which represents the Altay region over the past359yearsfrom the average temperature in June current year. Meanwhile several statistics areused to verify the reconstruction results. The results showed that the reconstructionvalue is credible. Reconstruction value analysis conclusions are as follows:（1）The average monthly temperature in June current year have a significantpositive correlation with the growth of tree rings. Both have significant effects on thephysiological role of trees.（2）The consequences of climate response with four standardized tree-ring widthchronologies from upper forest limits of the Altai Mountains were diverse. Thetemperature was the main limiting factor on the AKL chronology which located in thenorthwest of the Altai Mountains where in June the temperature effects on tree-ringwidth is more important than May; The precipitation was the first limiting factor onthe TEA and TZB chronology which located in the middle of the Altai Mountains，the temperature also had a certain role; The precipitation was the main limiting factoron the BLS chronology which located in the southeast of the Altai Mountains. Withthe tree-ring sampling sites along with the Altai Mountains moves from northwest tosoutheast， The influence of temperature variation on the tree-ring width growingwhich from the upper forest limits weakened gradually，While the role of precipitation increased gradually. In addition to the Altai Mountains on the northwestern tip，influence of precipitation is stronger than the temperature on tree-ring width which atthe upper forest limits sampling sites.(3) Average temperature reconstruction sequence roughly has7warm periods（1667-1681、1714-1728、1747-1779、1787-1800、1862-1887、1935-1968、2000-2012）and6cold periods（1682-1713、1729-1746、1780-1786、1801-1861、1888-1934、1969-1999）. The longest warm period spans33years (1935-1968), thelongest cold period spans46years（1888-1934）; In warm period (1935-1968), themaximum average temperature in June was20.65℃, and it’s0.23℃higher than theaverage. In cold period(1969-1999) the lowest average temperature in June is20.19℃, which is0.23℃lower than the average.(4) The average temperature sequence of reconstruction of359years (1653-2012)includes5warm year,54partial warm years,252normal years,11cold year,37partial cool years, as follows which respectively takes up1%,15%,70%,3%and10%. The extreme warm year occurred in1830（22.35℃）, which is higher than theaverage reconstruction1.93℃. The extreme cold occurred in1985(17.87℃)， whichis lower than the average reconstruction2.55℃.(5) It’s depicted from the data of dps software:1691,1857,1939and1970areabrupt points of monthly average temperature. Roughly in1691and1970, the averagetemperature in June changes from warm to cold, in1857and1970, it changes fromcold to warm.(6) The monthly average temperature reconstruction has30.0a,26.6a cycles (inJune current year).