• 关键词：无机氮沉降  森林群落  大气环境污染  华西雨屏区

• 基金项目：国家自然科学基金(No.31170423,31270498);高等学校博士学科点专项科研基金(No.20135103110002);四川省杰出青年学术与技术带头人培育项目(No.2012JQ0008,2012JQ0059);中国博士后科学基金(No.2012T50782)

• 赵海蓉
• 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130

• 帅伟
• 1. 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130;2. 甘孜藏族自治州林业研究所, 康定 626001

• 李静
• 1. 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130;2. 甘孜藏族自治州林业研究所, 康定 626001

• 杨万勤
• 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130

• 吴福忠
• 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130

• 谭波
• 四川农业大学生态林业研究所林业生态工程重点实验室, 温江 611130

• 摘要：氮沉降已成为河流、湖泊及城市等生态系统的主要污染威胁因素之一,森林生态系统能从林冠、地被和土壤自上而下截留过滤大气降雨中的NH₄⁺-N和NO₃^--N,是区域大气环境污染生态防治的重要途径.选取华西雨屏区几种典型人工林森林生态系统为研究对象,采用定位监测与室内分析相结合的研究方法,于2011年4—12月对大气降水、穿透雨、树干茎流、地表径流和地下渗滤NH₄⁺-N和NO₃^--N的含量与分配进行了研究.结果表明:观测期内40次降雨总雨量为492.72 mm,NH₄⁺-N和NO₃^--N的总沉降量分别为13.248 kg·hm^-2和16.320 kg·hm^-2;3种人工林林冠层对NH₄⁺-N和NO₃^--N的过滤能力表现为香樟林 >混交林 >柳杉林,而地表和土壤层均表现为混交林 >香樟林 >柳杉林;无林地、香樟林、柳杉林和混交林生态系统无机氮截留过滤净输入量分别为19.557、44.079、42.331、64.896 kg·hm^-2,对无机氮的综合过滤作用表现为混交林>香樟林>柳杉林>无林地.这些结果说明华西雨屏区合理配置混交林能更加有效地降低大气氮沉降对生态系统的影响.

• Abstract：Nitrogen deposition has become one of the main threat factors in polluted rivers, lakes and urban ecosystems. Forest ecosystems can intercept NH₄⁺-N and NO₃^--N from forest canopy, ground vegetation and soil during rainfall processes, which could be an important way to reduce the atmospheric pollution of nitrogen deposition. Several typical plantations including camphor (Cinnamomum longepaniculatum) plantations, cedar (Cryptomeria fortunei) plantations, their mixed plantations and a contrast land with none trees were selected in the rainy area of western China. The content and distribution of NH₄⁺-N and NO₃^--N were analyzed from atmospheric rainfall, throughfall, stemflow, surface runoff and soil percolating water from April to December, 2011. The results showed that there were 40 times rainfall with 492.72 mm and the total deposition of NH₄⁺-N and NO₃^--N were 13.248 kg·hm^-2 and 16.320 kg·hm^-2 over the observation period. The canopy interception of NH₄⁺-N and NO₃^--N were camphor plantation > mixed plantation > cedar plantation. However, the interception of ground vegetation and soil layer showed the order of mixed plantation > camphor plantation > cedar plantation. The net inorganic nitrogen inputs were 19.557 kg·hm^-2, 44.079 kg·hm^-2, 42.331 kg·hm^-2 and 64.896 kg·hm^-2 for contrast land, camphor plantation, cedar plantation and mixed plantation, respectively. The mixed plantation showed the higher efficiency of inorganic nitrogen interception compared with camphor plantation and cedar plantation. The results here suggested that reasonably mixed plantation could be more effective in reducing the negative influence of atmosphere nitrogen deposition in the rainy area of western China.

• Key words：inorganic nitrogen deposition  forest community  atmospheric environment pollution  rainy area of western China

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