浙北低山丘陵区天然次生林和人工毛竹林降雨化学特征比较  

Chemical Properties of Rain Water in Natural Secondary Forest and Artificial Bamboo Forest in Hilly Areas of North Zhejiang

作　　者：李谦[1] 王小明[1] 周本智[1] 

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江富阳311400

出　　处：《生态与农村环境学报》2014年第3期324-330,共7页Journal of Ecology and Rural Environment

基　　金：浙江省-中国林科院省院合作项目(2012SY03);中国林业科学研究院中央级公益性科研院所基本科研业务费专项(RISF6152);浙江省自然科学基金(LY12C16006)

摘　　要：森林降水化学特征定量研究对于准确估算森林生态系统养分循环的养分元素浓度有重要意义。以中亚热带人工毛竹林和天然次生林为研究对象，分析2种森林类型的穿透雨、地表径流和流域出口径流各离子浓度时空动态变化特征。结果表明，与人工毛竹林相比，天然次生林具有较高的林冠截留作用和枯落物截持水能力，产生的林内穿透雨和地表径流较少；大气降雨中各离子浓度差异较大，由高到低依次为SO42-、 NO3-、Na＋ 、Cl- 、K＋ 、Ca2＋、NH4＋ 和Mg2＋；人工毛竹林和天然次生林林内穿透雨的Na＋淋溶系数分别为0.49和0.85，而其他离子都有不同程度增加，表现为正淋溶；与大气降雨相比，2种林分的地表径流中各离子都表现为正淋溶，淋溶系数在1.127~10.16之间，以K＋和NO3-较大，而Na＋和NH4＋ 较小；流域出口径流中K＋和NH4＋相对于大气降雨有一定下降，迁移系数分别为0.90和0.21，而Ca2＋和Mg2＋浓度则明显增加，迁移系数分别为7.55和22.78；2种林分不同层次的降水化学特征差异主要表现在离子浓度上，除Na＋和Mg2＋外，天然次生林各层次的离子浓度均大于人工毛竹林。Quantitative study on chemical properties of rain water in forests is of great significance to accurate assessment of concentrations of nutrient elements recycling within forest ecosystem. A tract of planted bamboo forest and a tract of natural secondary forest in a low-mount-hilly area of North Zhejiang, located in the mid-subtropics was selected as subject in the study to explore spatio-temporal variation of various ions in waters of throughfall, surface runoff, and watershed effluent, relative to forest type. Results show that 1） compared with the bamboo forest, the natural secondary forest had a denser canopy capable of intercepting rainfall and a thicker litter layer capable of holding water, thus greatly reducing throughfall, and surface runoff; 2） concentrations of various ions varied sharply in the precipitation, displaying an order of SO42-〉NO3-〉Na＋ 〉Cl-〉K＋ 〉Ca2＋〉NH4＋ 〉Mg2＋; 3）.leaching coefficient of Na＋ with throughfall in the bamboo forest and natural secondary forest was 0.49 and 0.85 respectively, and those of the others increased to various degrees, manifesting positive leaching; 4） compared with rainfall, surface runoffs in both forests demonstrated positive leaching of all the ions, with leaching coefficient varying between 1.12 - 10.16, and K＋ and NO3- on the higher side and Na＋ and NH4＋ on the lower; 5）. watershed effluent was a bit lower than rainfall in K＋ and NH4＋ concentration, with net leaching coefficient being 0.90 and 0.21, but higher in Ca2＋ and Mg2＋ concentration, with net leaching coefficient being 7.55 and 23.78; and 6） the differences between the two forests in chemical properties of rain water at different levels were manifested in ion concentration. All the ions were higher in concentration in rain waters of all the levels in the natural secondary forest than in the bamboo forest, except Na＋ and Mg2＋.

关 键 词：穿透雨 地表径流 流域出口径流 降雨化学特征 森林 

分 类 号：S715.2[农业科学—林学]