摘要
为了解桉树人工林生态系统的降水再分配特征,改进桉树人工林经营方案,以提高林地保水保肥能力,本文依托广西南宁桉树林生态系统定位观测研究站,通过观测2015年7月—2016年5月历时11个月的尾巨桉林外降雨、林内降雨、穿透雨和树干径流,分析尾巨桉林冠降雨再分配特征。结果表明,研究期间的降雨总量1536 mm,穿透雨总量1042mm,占降雨总量68%;树干径流总量9.2 mm,占降雨总量0.6%;林冠截留总量490 mm,占降雨总量32%。月降雨量与穿透雨呈对数函数关系,当月降雨量超过25 mm即产生穿透雨;穿透雨和穿透率随降雨强度的增加而增加,当次降雨强度达暴雨以上时,林外降雨几乎全部形成林内降雨。在小雨、中雨、大雨和暴雨4种降雨强度条件下,累计降雨量与累计穿透雨均呈二次多项式递增函数,其中小雨和中雨的穿透雨初始时间滞后初始降雨分别约20min和10 min,而大雨和暴雨的穿透雨初始时间与降雨同步。树干径流虽在本文降雨分配计算过程中忽略不计,但其作用不可忽视。月降雨量与截留量呈递增幂函数关系,与截留率呈递减指数函数关系。
To understand the characteristics of rainfall redistribution of eucalypt plantations for improving management plan of eucalypt plantations so as to enhance capacity of water and soil conservation of forest stands, this paper did a research on monitoring outside and inside rainfall, throughfall and stemflow from July 2015 to May 2016 based on Guangxi Nanning Eucalypt Planta- tion Ecosystem Observation and Research Station to analyze characteristics of rainfall redistribu- tion of a Eucalyptus urophylla x E. grandis plantation. The results showed that the total of rainfall was 1536 mm, the total of throughfall was 1042 mm, which accounted for 68% of rainfall, the to- tal of stemflow was 9.2 mm, which only accounted for 0.6% of rainfall, and the total of intercep- tion was 490 mm, which accounted for 32% of rainfall. A logarithmic function relationship was established between monthly throughfall and rainfall, and an obvious throughfall was observed when rainfall was more than 25 mm. Throughfall and throughfall rate increased with increasing rainfall intensity; when rainfall intensity was more than rainstorm, the whole outside rain nearly penetrated canopy, forming inside rain. Under the conditions of light rain, moderate rain, heavy rain and rainstorm, accumulative throughfall showed an increasing quadratic polynomial function relationship with accumulative rainfall. Meanwhile, the throughfall beginning time of light rain and moderate rain lagged behind rainfall about 20 min and 10 min, respectively; however, the time of throughfall and rainfall showed a simultaneous change tendency under the heavy rain and rainstorm. In spite of too little stemflow which was ignored in the process of rainfall redistribution estimation, its role should not be neglected. Monthly rain showed a positive power function rela- tionship with monthly interception, but a negative exponential function relationship with intercep- tion rate.
出处
《生态学杂志》
CAS
CSCD
北大核心
2017年第6期1473-1480,共8页
Chinese Journal of Ecology
基金
广西林业科技项目(桂林科研[2015]第43号
桂林科字[2016]第24号)
国家重点研发计划(2016YFD0600504)资助
关键词
南宁
尾巨桉
林冠截留
穿透雨
树干径流
Nanning
Eucalyptus urophylla × E. grandis
canopy interception
throughfall
stemflow.
