黄泛区黄连木径向生长对气候要素的响应

Responses to Climatic Factors of Pistacia chinensis Radial Growth in the Yellow River Flooding Area

利用黄泛区沙丘上散生的黄连木树轮宽度进行生态学研究,以便揭示研究区黄连木的径向生长与气候因子之间的关系.建立的树轮差值年表中有较高的平均敏感度、信噪比和样本总体解释量,表明年表中含有较多的高频气候变化信息.年表序列与气候因子(月平均气温、月平均最高气温、月平均最低气温、月降水量和帕尔默干旱指数(PDSI))的相关结果表明:树轮宽度与前一年7月月平均气温和月平均最高气温以及当年6月月平均最高气温都呈显著负相关,而与前一年9月月平均最低气温和前一年12月、当年2月及6月降水量呈显著正相关,尤其与前一年7月月平均最高气温和当年2月降水量的相关性最高;与前一年11月至当年9月PDSI指数值都呈显著正相关,尤其6月和1-6月时段最突出.在此基础上,又对树轮序列中最窄和最宽年份进行了月均最高气温和月降水响应的实证分析,树轮宽窄变化与相关值最高的7月月平均最高气温和2月降水量及1-6月PDSI指数值的对照分析,并建立了树轮指数与1-6月PDSI指数的模拟方程.最后,利用树木出现的时间推断沙丘的形成应该与1938年花园口决堤有关.

The objective of this research was to disclose the dendroecology relationships between climatic factors and the radial growth scattered Pistacia chinensis in the Yellow River flooding area dunes. We developed residual chronology by collecting Pistacia chinensis increment cores. Higher mean sensitive and higher signal-to-noise ratio and expressed population signal indicate that the trees have more high-frequency climatic signals. The results between residual chronology and climatic factors （mean monthly air-temperature, mean monthly maximum temperature, mean monthly minimum temperature, precipitation and PDSI index） indicated the significant negatively correlations between tree ring width and July mean monthly air-temperature and mean monthly maximum temperature of the previous year and June mean monthly maximum temperature of the current year, nevertheless the significant positively correlated with September mean monthly minimum temperature of the previous year and precipitation of December of the previous year and February and June of the current year, especially it＇ s the highest value from July mean monthly maximum temperature of the previous year and February precipitation of the current year. Ring width indices were the significant positively correlated with PDSI from November of the previous year to September of the current year, especially June and January-June. On the basis of these results, this research made an empirical analyses on the narrowest and the widest ring-width years of chronology responding to mean monthly maximum temperature and precipitation, and contrast analysis on ring width change with the highest correlation climatic factors of July mean monthly maximum temperature of the previous year and February precipitation of the current year and January June PDSI, in order to verify the correctness of the correlation analysis. At the same time, we established regression equation between tree-ring indices and January June PDSI. Finally, we deduced that the dune growing Pistacia chinensis trees using trees appear time should be related with HuaYuanKou burst in 1938.