| 模拟氮沉降对重庆缙云山马尾松林土壤呼吸和酶活性的季节性影响 |
| 摘要点击 2323 全文点击 1025 投稿时间：2016-03-16 修订日期：2016-05-18 |
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| 中文关键词 模拟氮沉降 土壤呼吸 土壤酶 马尾松林 土壤温度 土壤湿度 |
| 英文关键词 simulated nitrogen deposition soil respiration soil enzymes Masson pine forest soil temperature soil moisture |
| 作者 | 单位 | E-mail | | 曾清苹 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400715
四川沃尔宜环保科技有限公司, 成都 610000 | 709904956@qq.com | | 何丙辉 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400715 | hebinghui@swu.edu.cn | | 李源 | 重庆市涪陵区林业局, 重庆 408000 | | | 夏力文 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400715 | | | 杨龙龙 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400715 | | | 邓雪梅 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400715 | | | 李川 | 重庆市涪陵区林业局, 重庆 408000 | |
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| 中文摘要 |
| 土壤酶参与土壤碳氮转化，同时土壤碳氮状况又是土壤酶活性的基础，而大气氮沉降通过影响土壤酶活性进而影响土壤CO2释放. 通过野外模拟试验，探讨不同氮沉降量对马尾松土壤呼吸和酶活性的影响，探索该区域马尾松土壤呼吸（Rs）与土壤温度（T）、土壤湿度（W）、Ure（脲酶）、Ive（转化酶）、CAT（过氧化氢酶）及ACP（酸性磷酸酶）的关系，为深入研究氮沉降对马尾松林森林生态系统的影响提供参考. 2014年5月~2015年7月在缙云山马尾松林设置3个氮添加水平和一个无氮添加的对照处理：低氮[N5，20 g·（m2·a）-1]，中氮[N10，40 g·（m2·a）-1]、高氮[N15，60 g·（m2·a）-1]和对照[N0，0 g·（m2·a）-1]，每个处理量分4次，在每个季度开始各施1次，每个处理各9次重复，采用ACE（automated soil CO2 exchange station，UK）自动土壤呼吸监测系统分别对土壤呼吸、土壤温度和土壤湿度进行分析测定. 结果表明：1土壤酶和土壤呼吸均具有明显的季节变化规律，各处理土壤呼吸均表现为夏季最高，其次是春季和秋季，最低为冬季，而各处理土壤酶活性则无一致的变化规律. 2总体而言，氮沉降对土壤呼吸和酶活性均有抑制作用，且抑制程度随氮浓度增加而加强，但冬季氮沉降对马尾松林土壤呼吸有促进作用，春、夏、秋这3个季节氮沉降对Ure、Ive、CAT及ACP有抑制作用，而冬季氮沉降对4种土壤酶活性影响则存在差异. 3逐步回归表明，无氮和低氮处理时，T、Ure和Ive对Rs的贡献较大，且随着T、Ure和Ive的增加，Rs也急剧增加；中氮处理时，T、Ure和CAT对Rs的贡献较大，Rs随着T、Ure和Ive的增加而增加；高氮处理时，Rs随着Ure的增加而降低，随着CAT和W的增加而增加. |
| 英文摘要 |
| Soil enzymes involved in the conversion of soil carbon and nitrogen, meanwhile the availability of soil carbon and nitrogen is the base of soil enzymes, yet atmospheric N deposition influences the release of soil CO2 by reduce the activities of soil enzyme. The objective of this study was to investigate the effect of different nitrogen deposition on soil respiration and soil enzymes, and explore the relationship among soil respiration, soil temperature, soil moisture and soil enzymes in the Masson pine forest. The results might provide a reference for further study on the effects of nitrogen deposition on pine forest ecosystem. From May 2014 to July 2015, three nitrogen application treatments and a control treatment were set up: low nitrogen [N5, 20 g·(m2·a)-1], moderate nitrogen [N10, 40 g·(m2·a)-1], high nitrogen [N15, 60 g·(m2·a)-1] and control treatment [N0, 0 g·(m2·a)-1) in the Masson pine forest. We measured soil respiration, soil temperature, and soil moisture simultaneously by using the Automated Soil CO2 Exchange Station (ACE, UK). The results showed that: 1 Soil enzymes and soil respiration had obvious seasonal variation, soil respiration of N0, N5, N10 and N15 was the highest in Summer, followed by the Spring and Autumn, and the lowest in Winter, and no consistent change rule was found in soil enzymes. 2 Generally, nitrogen deposition suppressed soil respiration and soil enzymes, and these inhibitory effects were strengthened with increasing levels of nitrogen deposition. The only exception in which nitrogen deposition enhanced soil respiration was in the Masson pine forest in Winter, In Spring, Summer and Autumn, nitrogen deposition suppressed soil enzymes, while there was difference among Ure, Ive, CAT and ACP in Winter. 3 stepwise regression showed that in control treatment and low nitrogen treatment, T, Ure and Ive made great contributions to the Rs, and Rs rapidly increased with the increase of T, Ure and Ive. In middle nitrogen treatment, T, Ure and CAT made great contributions to the Rs, and Rs increased with the increase of T, Ure and CAT. In high nitrogen treatment, Rs decreased with the increase of Ure, yet Rs increased with the increase of CAT and W. |
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