文档介绍：模拟氮沉降对瓦屋山常绿阔叶次生林土壤呼吸的影响*收稿日期 Received: 接受日期 Accepted:
*国家自然科学基金项目(31300522)、教育部高等学校博士学科点专项科研基金项目(20125103120018)、四川省教育厅重点项目(12ZA118, 13ZA0246) Supported by the National Natural Science Foundation of China (No. 31300522), the Specialized Research Foundation for the Doctoral Program of Higher Education(No. 20125103120018), the Key Project of Sichuan Provincial Department of Education(No. 12ZA118, 13ZA0246)
**通信作者 Corresponding author (E-mail:iamtlh@)
彭勇1 陈刚1 陈冠陶1 梁政1 涂利华1**
1四川农业大学林学院雅安 625014
摘要为理解氮沉降持续增加对次生林生态系统碳循环相关过程的影响,2013年5月开始对瓦屋山常绿阔叶次生林进行模拟氮沉降试验,氮沉降水平分别为对照(CK,0 kg N∙ hm–2∙ a–1)、低氮(LN,50 kg N∙ hm–2∙ a–1)和高氮(HN,150 kg N∙ hm–2∙ a–1)。于2013年9月至2014年8月,每月下旬采用LI-8100开路式土壤碳通量测量系统测定土壤呼吸速率。结果表明:瓦屋山常绿阔叶次生林土壤呼吸速率季节变化明显,7月最高( µmol·m−2·s−1),1月最低( µmol·m−2·s−1)。该次生林累积土壤碳排放量为591 g C ·m−2·a−1。土壤呼吸与土壤温度呈极显著正指数相关,与土壤湿度无显著关系。模拟氮沉降显著抑制了土壤呼吸,%。,低氮和高氮处理Q10值分别较对照增加16%和33%。在该生态系统土壤氮含量较高的背景下,模拟氮沉降可能加剧了土壤碳限制,通过减缓植物根系生长和降低土壤微生物生物量抑制了土壤CO2排放。图6表2参48
关键词氮沉降;土壤呼吸;Q10;根长密度;微生物生物量;常绿阔叶次生林
Effects of simulated nitrogen deposition on soil respiration in a secondary evergreen broad-leaved forest, Wawushan Mountain*
PENG Yong1, CHEN Gang1, CHEN Guantao1, LIANG Zheng1 & TU Lihua1**
College of Forestry, Sichuan Agricultural University, Ya’an 625014, China
Abstract
Objectives: To understanding the effect of nitrogen deposition on forest ecosystem carbon cycle, the response of soil respiration to nitrogen deposition is needed to be known. This paper aimed to reveal the soil respiration response mode to nitrogen deposition and its mechanism in a secondary evergreen broad-leaved forest in Wawushan Mountain.
Methods: From May 2013, a field experiment including three treatments was conducted in this secondary forest, i. e.,no N added (control), 50 kg N∙ hm–2∙ a–1 (low-N), and 150 kg N∙ hm–2∙ a–1 (high-N). From September 2013 to August 2014, the author used LI-8100 to investigate the soil respiration rate at the end of each month.
Results: S