摘要
在福建南平地区 ,选择离污染源距离不同的两片杉木人工林建立监测场 ,对降雨、穿透雨和树干径流化学进行了连续 3年 ( 1 994～ 1 996)的定位研究。降雨通过林冠后 ,其化学性质发生了显著的变化。穿透雨较降雨的 pH值稍低 ,但伴随离子浓度的增加 ,穿透雨的电导率明显升高 ,而树干径流的酸化和养分富集现象均十分显著。降雨和穿透雨酸度表现出一定的季节变化趋势 ,其最低月均 pH值普遍出现在夏季 ,最高值在冬季。而降水电导率则表现出与离子浓度相同的明显的季节变化格局 ,两者月均值均以夏季最低 ,冬季最高 ,春秋季居中 ,这种格局强烈受降雨量的控制。树干径流酸度与SO2 4 浓度之间密切相关 ,但降雨和穿透雨的氢离子浓度和酸 碱离子浓度比R[R =(SO2 -4 +NO3 -) /(Ca2 + +Mg2 + ) ]间相关显著。离污染源距离的远近对降水化学的影响也比较明显。
The chemistry of rainfall,throughfall and stemflow was measured continuously for three years (1994～1996) in two Chinese fir forests with different distances from pollution source in Nanping,Fujian. Precipitation chemistry was dramatically altered upon passage through forest canopies at both sites.The pH values in throughfall decreased slightly,but EC values were significantly higher because of its higher ion concentrations than in rainfall. Stemflow showed extremely acidification and nutrient enrichment.Acidity of rainfall and throughfall showed some seasonal patterns,generally with minimal pH values in summer,maximal in winter.However,the EC values of precipitation exhibited strong seasonal patterns practically identical to that for ion concentrations,consistently with minimal values in summer months,intermediate in spring and fall,and maximal in winter,which appeared highly dependent on rainfall amount.Close correlation exited between acidity and sulfate in stemflow,but hydrogen concentrations in rainfall and throughfall were strongly related to acid\|base ratios R,which equals to (SO 4 2- +NO 3 -)/(Ca 2+ +Mg 2+ ).Lastly the distances from pollution sources produced significant effects on precipitation chemistry.
出处
《林业科学》
CAS
CSCD
北大核心
2000年第4期2-8,共7页
Scientia Silvae Sinicae
基金
日本国际绿化推进中心! (JapanInternationalForestryPromotionandCooperationCenter)资助项目
关键词
杉木林
降雨
穿透雨
树干径流
降水化学
Chinese fir forest,Rainfall,Throughfall,Stemflow,Chemical composition,Seasonal dynamics
