罗山树木年轮指示的近100年来3-8月湿润指数的变化

he tree-ring width of Pinus Tabulaeformis from Luoshan Mountains correlates positively with the monthly precipitation and negatively with the monthly temperature during the growing season. There is a more significant relation between tree-ring width and the moisture index (P/T): the simultaneous influence of precipitation and temperature. The reconstructed equation of the moisture index from March to August is developed using the tree-ring width, with a correlation coefficient of 0.621, and reaches 0.001 significent level. The reconstructed moisture index shows that there is a markable change of humid and dryness during recent 100 years, The reconstructed moisture index lower than average reflects the drought years recorded in historical documents; By constrasting with other areas, the dry period from 1923 to 1931 is correspondent with the period of high temperature and low precipitation during the 1920s' and 1930s' at Northwest, North China and Yangtze River Basin in China. Moreover, the humid period from 1939 to 1944 corresponds well with those of Qilianshan Mountains, the south Plateau of Qinghai and the East Tianshan Mountains, etc, and also with the period of low temperature and high precipitation after 1940s' at Northwest, North China and Yangtze River Basin in China. After primary analysis we conclude that the moisture index within 100 years of Luoshan records the dry and wet change of Northwest at least and may be close with the climatic change in large range.