Reconstruction of humidity changes from tree rings in Liupan Mountains area since 1900
Wang MengmaiDai JunhuBai JieCui Haiting
1 Institute of Geographic Sciences and Natural Resources Research， Chinese Academy of Sciences， Beijing 100101
2 Graduate School of Chinese Acadamy of Sciences， Beijing 100049
3 College of Urban and Environmental Sciences， Peking University， Beijing 100871
ean relative humidity from April to May was estimated based on tree ring width data of Pinus tabulaeformis from 1900 onwards in the Liupan Mountains area. The radial growth of Pinus tabulaeformis in this region was significantly affected by the mean relative humidity in spring. On the basis of response analysis， the mean relative humidity changing succession from April to May was reconstructed， and the reconstruction equation was of good stability with correlation coefficient of 0557. As indicated by the spectral analysis， the reconstructed series displays significant cycles of 4-7 years. Its clear that there are four relatively dry periods: 1905-1916， 1918-1932， 1941-1946 and 1955-1962， and four relatively wet periods: 1900-1904， 1934-1939， 1948-1953 and 1964-1973. The most dry periods are 1905-1915 and 1922-1932.
tree rings， relative humidity， Liupan Mountains
