| 我国西南地区氮饱和马尾松林土壤和植物15N自然丰度对长期氮施加的响应 |
| 摘要点击 1993 全文点击 1204 投稿时间：2015-01-24 修订日期：2015-03-09 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 15N自然丰度 氮饱和 马尾松林 N沉降 15N富集因子 |
| 英文关键词 15N natural abundance N saturation masson pine forest N deposition 15N enrichment factor |
| 作者 | 单位 | E-mail | | 刘文静 | 清华大学环境学院,国家环境保护大气复合污染来源与控制重点实验室,北京 100084 | wenjingliuthu@163.com | | 康荣华 | 挪威生命科学大学环境科学学院,奥斯 NO-1432,挪威 | | | 张婷 | 清华大学环境学院,国家环境保护大气复合污染来源与控制重点实验室,北京 100084 | | | 朱婧 | 挪威生命科学大学环境科学学院,奥斯 NO-1432,挪威 | | | 段雷 | 清华大学环境学院,国家环境保护大气复合污染来源与控制重点实验室,北京 100084 | lduan@tsinghua.edu.cn |
|
| 中文摘要 |
| 我国快速增长的氮沉降可能造成森林生态系统的氮饱和,进而导致一系列严重的环境后果. 为了深入研究氮沉降对我国森林生态系统的影响,进而评价和预测森林生态系统的氮状态,本研究选取我国西南地区典型的马尾松林生态系统,对土壤和植物的15N自然丰度(δ15N)进行了测定,探讨用15N富集因子(εp/s)作为氮状态指标的可行性. 对该马尾松林连续7 a施加NH4NO3或NaNO3的控制实验结果表明,长期的高氮输入显著增加了土壤和植物的δ15N. 同时,该生态系统对不同形态的氮输入有不同的响应,即在NH4+沉降下δ15N显著高于NO3-沉降下的值.15N富集因子与氮沉降量、净硝化速率和淋溶量均呈显著的正相关关系,特别是本研究与之前研究的所有马尾松林的15N富集因子与氮沉降量之间线性相关,表明15N富集因子可用来表征氮状态. 由于在相同氮沉降的情况下,NH4+的效应强于NO3-,建议我国在未来控制氮氧化物排放的同时也应当重视氨的排放控制. |
| 英文摘要 |
| Increasing N deposition in China will possibly cause N saturation of forest ecosystem, further resulting in a series of serious environmental problems. In order to explore the response of forest ecosystem to N deposition in China, and further evaluate and predict the N status of ecosystem, the 15N natural abundance (δ15N) of soil and plants was measured in a typical Masson pine (Pinus massoniana) forest in southwest China to examine the potential use of 15N enrichment factor (εp/s) as an effective indicator of N status. Long-term high N addition could significantly increase δ15N of soil and plants, which was suggested by an on-going N fertilizing experiment with NH4NO3 or NaNO3 for 7 years. Meanwhile, δ15N of soil and plants under NH4+ deposition was significantly higher than that under NO3- deposition, suggesting different responses of ecosystem to different N-forms of deposition. The 15N enrichment factor (εp/s) had positive correlations with N deposition, N nitrification, and N leaching in the soil water. Linear correlation between 15N enrichment factor and N deposition was found for all Masson pine forests investigated in this and previous studies in China, demonstrating that 15N enrichment factor could be used as an indicator of N status. The NH3 emission control should also be carried out accompanying with NOx emission control in the future, because NH4+ deposition had significantly greater impact on the forest ecosystem than NO3- deposition with the same equivalence. |
|
|
|
