施氮对不同土壤有机碳水平桉树人工林温室气体通量的影响
文献类型：学位论文
| 作者 | 李睿达 |
| 学位类别 | 硕士 |
| 答辩日期 | 2014-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 郑华,王效科 |
| 关键词 | 温室气体 施肥梯度 土壤有机碳 交互作用 桉树人工林 greenhouse gases nitrogen levels soil organic carbon interaction effect Eucalyptus plantation |
| 其他题名 | Impacts of nitrogen application on greenhouse gases fluxes in a Eucalyptus plantation with different soil organic carbon levels |
| 学位专业 | 生物工程 |
| 中文摘要 | 施氮或氮沉降对森林土壤温室气体通量影响已有比较深入的研究，但施氮对不同土壤有机碳水平人工林土壤温室气体通量的影响很少研究。本研究以我国南方广泛种植的桉树人工林为对象，采用野外控制实验和室内分析，比较研究了4种施氮处理（对照 C：0 kg∙hm-2；低氮 L：84.2 kg∙hm-2；中氮 M：166.8 kg∙hm-2；高氮 H：333.7 kg∙hm-2）对土壤有机碳水平存在显著性差异的 2块桉树人工林样地土壤温室气体（CO2、N2O和 CH4）通量的影响。结果表明： （1）施氮后 CO2和 N2O排放通量出现明显的激发效应。施氮 1个月后各个处理土壤 CO2和 N2O排放通量出现最高值，且施氮处理下的排放通量显著高于对照（P<0.01），至生长季后期 CO2和N2O排放通量逐渐降低，处理间差异逐渐缩小。CH4吸收通量的季节性动态变化不明显。 （2）施氮强度和土壤有机碳含量是影响土壤 CO2和N2O排放的重要因素。施氮极显著增加 N2O排放通量（P<0.001），高氮处理显著促进CO2排放同时显著抑制 CH4吸收（P<0.05）。高土壤有机碳水平样地CO2和 N2O排放通量显著高于低水平土壤有机碳样地（P<0.01）；CH4吸收通量在 2个样地间无显著性差异（P>0.05）。 （3）施氮和土壤有机碳对CO2和N2O排放通量的影响存在显著的交互作用P<0.05）。与低土壤有机碳水平样地比较，高土壤有机碳水平样地 CO2和N2O排放通量对施氮的响应更为敏感。高土壤有机碳样地的高氮处理显著促进了 CO2排放（P<0.05），而低土壤有机碳样地的高氮处理并未显著促进 CO2排放（P>0.05）。高氮处理下高有机碳样地的N2O排放通量显著高于低有机碳样地的N2O排放通量（P<0.05）。低氮处理能显著增加N2O的排放；而低土壤有机碳水平样地的中氮处理才能显著增加N2O的排放（P<0.01）。 （4）桉树人工林生长季土壤排放（或吸收）的 3种温室气体之间存在显著的相关关系（P<0.01）。CO2通量与 N2O通量之间表现出显著的正相关关系，CH4与CO2和N2O均表现出显著负相关关系。 （5）环境因素对低、高土壤有机碳水平桉树人工林土壤的温室气体排放产生显著影响。5cm处土壤温度与CO2和N2O排放通量存在极显著正相关关系（P<0.001）。10 cm处土壤含水量与 N2O排放通量存在显著相关（P<0.05）。 上述研究结果表明：施氮对桉树人工林温室气体通量的影响既与施氮强度有关，也与土壤有机碳水平密切相关。估算不同施氮水平下的温室气体通量变化时，由土壤有机碳不同带来的温室气体通量差异不可忽视。同时，本研究结果也可为评估施肥对人工林土壤温室气体通量的影响提供参数。 |
| 英文摘要 | It had been well studied that effects of nitrogen fertilization or nitrogen deposition on forest soil greenhouse gases fluxes. While little had been piloted about the effects of nitrogen application on soil greenhouse gas fluxes with different soil organic carbon content. In our study, we conducted in the Eucalyptus plantation in Southeast China. Combined with field control experiment and lab analysis, we compared 4 levels of nitrogen fertilization (Control: 0 kg∙hm-2; Low N: 84.2 kg∙hm-2; Medium N: 166.8 kg∙hm-2; High N: 333.7 kg∙hm-2) on soil GHGs fluxes from two sites (LC and HC) whose soil organic carbon (SOC) had significant difference (P<0.05). The results shown: (1) Fertilization had significant priming effects on CO2 and N2O emission fluxes. In a month after fertilization, both CO2 and N2O had the flux peaks and decreased by the end of growing season, and the differences among the treatments gradually disappeared. However, CH4 oxidation fluxes had no significant temporal dynamics between the two sites during growing season. (2) The amount of fertilization and SOC levels were two crucial factors that has significant effect on CO2 and N2O (P<0.001).Fertilization strongly increased N2O emission fluxes (P<0.001)。High N treatment had a significant positive effect on CO2 emission, and significantly depressed CH4 oxidation (P<0.05). CO2 and N2O emission fluxes were significant higher in HC than that in LC (P<0.01), but no difference was found in CH4 oxidation fluxes between two sites (P>0.05). (3) Fertilization and SOC had great interactive effect on CO2 and N2O emission (P<0.05). Compared with fluxes in LC, the fluxes in HC were much more sensitive to N input. High N could promote CO2 emission significantly in HC site (P<0.05), but it had no significant effect on CO2 emission in LC (P>0.05). N2O emission fluxes in HC site was significant higher than that in LC site under High N treatment. Also, in HC site, Low N could stimulate N2O emitted remarkably (P<0.01), while Medium N could significantly arouse N2O emission in LC site (P<0.01). (4) During the growing season, GHGs fluxes shown significant correlationships (P<0.01). Soil CO2 and N2O emission fluxes following fertilization in two sites revealed a strong interaction, and soil CH4 oxidation had significant negative relationship between both CO2 and N2O emission. (5) Environmental factors had significant effects on soil greenhouse gases. Soil temperature at 5 cm was the main environmental factor affected the CO2 and N2O emission flux (P<0.001). Soil water content also had a significant effect on N2O emission (P<0.05). Soil temperature and water content displayed week effects on soil CH4 uptake. In conclusion, the effects of nitrogen fertilization on soil GHGs fluxes are not only in connection with intensify of nitrogen, but also closely tied to the SOC content. When we assess the effects of nitrogen on soil GHGs fluxes, the difference induced by SOC should not be ignored. |
| 公开日期 | 2015-07-07 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/15718]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 李睿达. 施氮对不同土壤有机碳水平桉树人工林温室气体通量的影响[D]. 北京. 中国科学院研究生院. 2014. |
入库方式： OAI收割
来源：生态环境研究中心
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。