The Study On Climatic Reconstruction And Analysis Based On The Dendroclimatology

This paper was taking dendroclimatology as the theoretics basic, taking Dagang Mountain as the area of case study and taking Pinus massoniana as the object. Based on the results of correlation and response analysis, we try to reconstruct the last climate change of Dagang Mountain. The main conclusions are summarized as follows:(1) A 133-year tree-ring standardized chronology was established based on the samples collected from Mt. Dagangshan. Statistical analysis of the chronology showed mean series inter-correlation of 0.52, mean sensitivity of 0.27, and signal-to-noise of 25.70. The results indicated that the tree-ring chronology records more information of environmental changes. And the tree-ring chronology was fit for the dendroclimatologic study.(2) The correlation and response analysis show that the standard tree-ring chronologies was positively correlated with temperature from July to September and April precipitation and moisture index of the current year, and was negatively correlated with June mean temperature, January and September precipitation and index, January, February, April, June, July, September and November mean minimum temperature and April and June mean maximum temperature.(3) Comparing with the month change and the season change, the STD chronology had higher correlation coefficient with mean temperature, precipitation and moisture index from July to September of the current year. By using stepwise regression analysis, we established the temperature reconstruction equation Y=1.434X + 25.320, precipitation reconstruction equation Y= e(-0.308X+5.115) and moisture index reconstruction equation Y= -1.592X + 6.187. The July-September mean temperature, precipitation and moisture index were reconstructed for the past 117 years, and the reconstructions were stable as evaluated by crossing-test.(4) The reconstruction shows that the July-September mean temperature had experienced three warm periods 1895-1902, 1908-1926 and 1944-1985, and three cold periods 1903-1907, 1927-1943 and 1986-2008. The mean temperature series had abrupt changes in years 1921, 1937 and 1977.(5) The reconstruction shows that the July-September precipitation had experienced three dry periods 1895-1902, 1908-1926 and 1944-1985, and three wet periods 1903-1907, 1927-1943 and 1986-2008. The precipitation series had abrupt changes in years 1921, 1937 and 1977.