河北太行山南段树木年轮指示的167年来相对湿度变化研究

研究建立了河北太行山南段侧柏(Platycladus orientalis)树轮宽度年表,分析树木径向生长对水热变化的响应,构建了研究区167年来相对湿度变化序列。结果表明,侧柏树轮宽度与6月降水显著正相关,与5—7月逐月均温和最高温均显著负相关,侧柏径向生长受到春末夏初水热条件的显著制约。研究区167年来干湿变化明显,明显的干旱期有1876—1877,1900—1901,1904—1912,1918—1921,1926—1930和1933—1935年,湿润期有1871—1873,1882—1884,1888—1890,1893—1895,1953—1956,1971—1972和2002—2003年。5—7月相对湿度变化与旱涝等级负相关达到0.01显著水平。周期分析表明,167年来5—7月相对湿度变化存在2—4年、7.71年和60年左右周期,可能与太平洋活动、太阳活动有一定关联。

The study of variation in relative humidity from May to July during the past 167 years in the Southern Taihang Mountains in Hebei Province

In this paper, tree-ring width chronologies of Platycladus orientalis were developed from the southern Taihang Mountains in Hebei Province. The response of tree radial growth to hydrothermal change was analyzed, and the mean relative humidity from May to July during the past 167 years was reconstructed. The results showed that tree radial growth of Platycladus orientalis responded significantly and positively to June precipitation, and negatively to mean temperature and the maximum in May, June, and July. The tree radial growth of Platycladus orientalis was restricted by hydrothermal conditions in late spring and early summer. The reconstruction showed that there was a markable change in humidity and dryness during the recent 167 years. Obvious dry periods occurred in 1876-1877, 1900-1901, 1904-1912, 1918-1921, 1926-1930, and 1933-1935, and humid period occurred in 1871-1873, 1882-1884, 1888-1890, 1893-1895, 1953-1956, 1971-1972, and 2002-2003. The reconstruction series was negatively related to the drought and flood level index at the 0.01 significance level. Cycle analysis showed that the reconstruction of relative humidity from May to July during the past 167 years had periods of approximately 2-4 years, 7.71 years, and 60 years.