Tree-ring Climatology of Larix gmelinii in Maoershan Region,Northeastern China

Abstract

Through collecting the meteorological data,sampling and standardizing the data of tree rings of larch(Larix gmelinii),the climatic changes in Maoershan region were analyzed and their influences on tree ring features were studied in this paper.In the past 50 years,significant increases in temperature were found(p0.05),i.e.about 0.4℃ per decade in average annual temperature,0.3℃ per decade in average annual maximum temperature as well as 0.5℃ per decade in annual average minimum temperature were observed.However,no significant change in annual precipitation was found(p0.05).Average monthly temperature(average temperature,average maximum temperature,average minimum temperature) also showed increasing tendencies and the most significant month was in February of the winter,about 0.9-1℃ per decade.Much smaller temperature increases,ca.0.2-0.7℃ per decade was found in June to August of the summer).No significant change in monthly precipitation was found in most months(p0.05).During the coming climate warming,widths of early and whole tree rings(p0.05) might be decreased with the temperature increment in summer(June to July),while widths of early and the growth of tree rings would increase with the temperature increases in spring(May).The width of late might be increased with the temperature increases in autumn(September).These might cause the non-obvious change in ring width with annual temperature changes(p0.05).Although non-significant changes in precipitations,the significant correlations between annual precipitation and variable tree rings indices indicated the growths of early wood and whole tree rings might be positivity affected by the amount of annual precipitations.Considering the warming trend of the climate change is significant in northeast China in future but the rainfall does not.The growth of tree rings caused by spring and autumn temperatures could be offseted by too high temperatures in summer which inhibited the tree ring growth.Therefore,the influence on the radial growth of the Larix might be little.