Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 城市绿地土壤呼吸速率的变化特征及其影响因子 DOI: 10.5846/stxb201601080058 作者: 作者单位: 广东工业大学,广东省环境科学研究院,广东省环境科学研究院,福建农林大学,广东省环境科学研究院,广东工业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学青年基金资助项目(31470703) Controlling factors of variation in soil respiration rate in urban green-space ecosystems Author: Affiliation: Guangdong University of Technology,Guangdong Provincial Academy of Environmental Science,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:城市绿地土壤呼吸作用深刻影响着城市生态系统碳循环过程,强化城市绿地土壤呼吸速率(Rs)的变化特征及其影响因素的研究,可揭示绿地在城市生态系统碳循环过程中的作用,为优化布局城市绿地和实现低碳排放目标提供科学依据。以广州市海珠湖公园的疏林、灌丛和草地3种典型植被类型的土壤为研究对象,于2013年11月-2014年10月采用静态箱-气相色谱法对公园绿地Rs进行跟踪观测。结果表明:海珠湖公园城市绿地在干湿季节中Rs差异显著;干季Rs较低且波动幅度较小,疏林、灌丛和草地的Rs变化范围分别为(1.66±0.18)-(3.26±0.20)μmol m-2 s-1、(1.27±0.15)-(3.67±0.16)μmol m-2 s-1和(1.94±0.08)-(6.82±1.13)μmol m-2 s-1;湿季Rs较高且波动幅度较大,疏林、灌丛和草地的Rs变化范围分别为(3.53±0.46)-(13.81±1.31)μmol m-2 s-1、(2.82±0.22)-(12.72±1.16)μmol m-2 s-1和(2.80±0.30)-(9.83±0.96)μmol m-2 s-1。T10和VWC10均对土壤呼吸过程有重要的影响,进一步通过回归分析得出,土壤10cm处温度(T10)和体积含水量(VWC10)分别解释Rs时间变异的40%左右和10-24%左右。T10和VWC10相互影响、共同作用于土壤呼吸过程,双因素复合模型的解释能力较单因素模型明显提高,均在50%以上,复合模型为Rs=α·exp(β·T10+γ·VWC10)。干湿季土壤呼吸的温度敏感性(Q10)有明显差异,湿季的Q10比干季的分别高0.44、0.70和0.46。 Abstract:Soil respiration is a major component of the carbon cycle in terrestrial ecosystems, and small changes have a significant effect on CO2 concentration in the atmosphere. Previous studies from different terrestrial ecosystems have confirmed that soil respiration is related to both global climate change and the carbon cycle. However, many studies have focused on non-urban ecosystems, such as forests, farmlands, and grasslands, while fewer studies have examined soil respiration in urban green-space ecosystems. In particular, few studies have addressed whether soil respiration is affected by different vegetation types in urban green-space ecosystems. This research explored soil respiration rate (Rs) in three different vegetation types in urban green-space, to provide basic scientific data on the contribution of urban green-space to the carbon cycle in urban ecosystems. Results will also facilitate the optimization of landscape patterns in urban green-spaces to reduce carbon emissions. In this study, Rs of three representative vegetation types (woodland, scrubland, and grassland) were investigated in Haizhu Lake Park of Guangzhou, Guangdong Province, China. From November 2013 to October 2014, we measured Rs monthly using a static chamber and gas chromatography, while simultaneously measuring soil temperature and volumetric water content. Results showed a significant difference in Rs between the wet and dry seasons. A relatively lower Rs, with less fluctuation, was noted in the dry season:(1.66±0.18)-(3.26±0.20) μmol m-2 s-1 for woodland, (1.27±0.15)-(3.67±0.16) μmol m-2 s-1 for scrubland, and (1.94±0.08)-(6.82±1.13) μmol m-2 s-1 for grassland. Conversely, a relatively higher Rs, with much more fluctuation, was noted in the wet season:(3.53±0.46)-(13.81±1.31) μmol m-2 s-1 for woodland, (2.82±0.22)-(12.72±1.16) μmol m-2 s-1 for scrubland, and (2.80±0.30)-(9.83±0.96) μmol m-2 s-1 for grassland. In addition, environmental factors that influenced soil respiration were very complicated in these urban green-space ecosystems, and two relatively important factors were soil temperature at 10 cm depth (T10) and soil volumetric water content at 10 cm depth (VWC10). Regression analysis showed that the exponential model explained the relationship between T10 and Rs well; T10 explained approximately 40%, while VWC10 explained 10%-24% of Rs variation across months. Notably, a dual-factor (including both T10 and VWC10) model:Rs=α·exp (βT10+γVWC10), better explained Rs variation across months, accounting for over 50% of Rs variation. Furthermore, a significant difference was noted in temperature sensitivity of soil respiration (expressed as Q10) between the wet and dry seasons; the wet season had a greater Q10 value than did the dry season (0.44, 1.15and 0.46, respectively). This study analyzed the differences in soil respiration and influential factors (T10 and VWC10) between three typical vegetation types in urban green-space ecosystems. However, there are many other potentially influential factors that were not considered, and further researcher is needed to explore these in the future. 参考文献 相似文献 引证文献

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