摘要
[目的]以大兴安岭地区兴安落叶松林为研究对象,分析降雨特征对兴安落叶松林降雨再分配过程中K^+的影响。[方法]对林外降雨、穿透雨、灌木穿透雨、树干径流和枯透水进行了野外观测、取样和室内实验测定。[结果]结果表明:(1)研究期间兴安落叶松林林外降雨总量为266.0 mm,平均次降雨强度0.074 mm·min^(-1);降雨再分配过程中K^+含量平均值排序为枯透水>树干径流>灌木穿透雨>穿透雨>林外降雨,其中林外降雨中K^+含量在0.227 2.631 mg·L^(-1)之间,变化幅度较大,穿透雨中K^+含量波动在2.198 3.053 mg·L^(-1)之间,枯透水中K^+含量波动较小,稳定在3.077 3.281 mg·L^(-1)之间。(2)降雨量和降雨历时对降雨再分配过程中K^+含量均表现为正相关,随降雨量和降雨历时的增加K+含量的增加幅度呈上升趋势;而降雨强度和降雨间隔期对K^+含量增加幅度的影响则反之,但当降雨强度大于0.041 mm·min^(-1)时,K+含量的增加幅度开始出现转折,呈上升趋势;当降雨间隔期增大至233.28 h时,K^+含量的增加幅度趋于稳定。(3)影响林外降雨中K^+含量的主导因子是降雨间隔期,影响穿透雨、灌木穿透雨和树干径流中K^+含量的主导因子均为林外降雨量,而对枯透水中K^+含量起主导作用的则为降雨强度。[结论]降雨量、降雨历时、降雨强度以及降雨间隔期均会对降雨再分配过程中各个层次的K^+含量产生不同程度的影响。降雨再分配过程中K^+含量平均值大小排序为枯透水>树干径流>灌木穿透雨>穿透雨>林外降雨,其中大气降雨中K^+含量在5月和9月较高,穿透雨中K^+含量在5—10月呈波动式变化,灌木穿透雨中K^+含量变化幅度较大,而树干径流和枯透水中K^+含量较稳定。降雨量和降雨历时对降雨再分配过程中K^+含量的影响均表现为正相关。对林外降雨中K^+含量影响程度由大到小排序依次为降雨间隔期>降雨强度>降雨历时>降雨量,穿透雨中K^+含量与各影响因素的灰关联度大小顺序依次为降雨量>降雨历时>降雨强度>降雨间隔期,灌木穿透雨和树干径流中K^+含量与各影响因素的灰关联度排序和穿透雨一致,影响的主导因子均为降雨量,枯透水中K^+含量与各影响因素的灰关联度大小顺序依次为降雨强度>降雨间隔期>降雨历时>降雨量。
Selecting Larix gmelinii forest in Great Xing＇anling Mountains as a research object, to analyze the effects of rainfall characteristics on potassium content in L. gmelinii forest during the process of rainfall redistribution. [Method]The precipitation, throughfall, shrub throughfall, stem flow and litter water were observed, sampled and measured. [Result]The results showed that：（1）During the observation period, the rainfall outside of stands was 266.0 mm, the average rainfall intensity was 0.074 mm·min-1; the order of the average content of K＋ during the rainfall redistribution was litter water 〉 stem flow 〉 shrub throughfall 〉 throughfall 〉 precipitation, the content of K＋ during precipitation changed greatly, the value fluctuated between 0.227~2.631 mg·L-1, the stem flow fluctuated between 2.198~3.053 mg·L-1, the content of K＋ in litter water was the most stable, fluctuated between 3.077~3.281 mg·L-1. （2） It was found that the content of K＋ increased with the increase of rainfall and rainfall duration. However the rainfall intensity and inter-events interval were just the opposite unless the rainfall intensity was higher than 0.041 mm·min-1. When the rainfall interval increases to 233.28 h, the increase of the content of K＋ became stable. （3） The leading factor influencing the K＋ content in rainfall outside stand was the rainfall interval. The key factor influencing the K＋ content in throughfall, shrub throughfall and stem flow was the precipitation. The rainfall intensity was the key factor influencing the K＋ content of litter water. [Conclusion]The Precipitation, rainfall duration, rainfall intensity and rainfall interval would influence the K＋ content during the process of rainfall redistribution in varying degrees.
出处
《林业科学研究》
CSCD
北大核心
2017年第2期307-314,共8页
Forest Research
基金
林业公益性行业专项(201404303-2)
关键词
兴安落叶松林
降雨量
降雨强度
降雨间隔期
钾元素
灰关联度
Larix gmelinii tbrest
rainfall
rainfall intensity
inter - events interval
potassium
grey correlation degree
