黑河天涝池五种植被类型土壤呼吸速率动态特征及其影响因子

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 黑河天涝池五种植被类型土壤呼吸速率动态特征及其影响因子 DOI: 10.5846/stxb201311102706 作者: 作者单位: 兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室,兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室,兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室,兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室,兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室,兰州大学生命科学学院干旱农业生态研究所草地农业生态系统国家重点实验室 作者简介: 通讯作者: 中图分类号: S154.4 基金项目: 国家自然科学基金项目(91025015) Variation in soil respiration rate and factors affecting it in five vegetation types in Tianlaochi catchment in Heihe River Author: Affiliation: State Key Laboratory of Grassland AgroEcosystem,Institute of Arid AgroEcology,School of Life Sciences,Lanzhou University,甘肃,甘肃,甘肃,甘肃,甘肃 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:对黑河天涝池流域的5种典型植被类型(干草原、亚高山草原、亚高山灌丛、祁连圆柏林和青海云杉林)的土壤呼吸速率及其影响因子进行测定分析。结果表明:5种植被类型土壤呼吸速率具有典型的日变化和月变化模式;5种植被类型土壤呼吸速率大小表现为亚高山草原 > 干草原 > 亚高山灌丛 > 祁连圆柏林 > 青海云杉林,土壤呼吸速率的变化范围因植被类型的不同而有所差异;5种植被类型土壤呼吸速率与土壤温度、地表温度和大气温度呈显著的指数关系,且与地表温度和大气温度的相关性强于土壤温度;5种植被类型的土壤呼吸速率与湿度呈显著的线性负相关,R2为 0.55-0.93,与风速呈显著的线性正相关关系;通过主成分分析表明影响5种植被类型土壤呼吸速率的主要因素各不相同,整体表现为在整个生长季 0-60 cm土壤的水热状况是主要的影响因素,其次是土壤表层的环境因子,最后为太阳辐射。 Abstract:Soil respiration (Rs) is an important component of an ecosystem's carbon cycle and the main pathway for carbon release from the ecosystem into the atmosphere. The transfer of carbon between the ecosystem and atmosphere is of interest in the study of greenhouse gas emission. In order to understand characteristics of the Rs dynamics and the factors controlling it, this study was conducted in five typical vegetation types in Tianlaochi catchment area of the Heihe River, located in Qilian Mountains, Northwestern China. Rs, soil temperature, and soil moisture were measured by an automated soil CO2 flux system (LI-8100) from May to September in 2013, and weather data for the corresponding study period were obtained from the weather station located in the experimental plot. The results showed that Rs in the five vegetation types displayed clear diurnal dynamic pattern. The Rs rate differed in different vegetation types, from the highest in subalpine steppe (2.01 to 12.10 μmol m-2 s-1), followed by Stipa purpurea steppe (1.40 to 8.45 μmol m-2 s-1), subalpine shrub (0.85 to 9.24 μmol m-2 s-1), Sabina przewalskii forest (1.09 to 4.14 μmol m-2 s-1), to the lowest in Picea crassifolia forest (1.25 to 3.19 μmol m-2 s-1). The daily change of Rs followed the fluctuations in surface air temperature, and there was a hysteresis between Rs and soil temperature. Rs rate had obvious seasonal variation, increasing from May and reaching the maximum in July, and then decreasing until the final measurements in September. The statistical analysis indicates that Rs rate was significantly positively correlated with soil temperature, surface air temperature, and air temperature, which relationship can be expressed with an exponential function. In relation to the temperature, Rs rate was more correlated to surface air temperature and air temperature than to soil temperature. For example, surface air temperature explained 79%-95% of the variation of Rs rate during the observation period, and air temperature explained 50%-77%, whereas soil temperature in the top 10 cm layer explained only 23%-47%; Rs rate had a significantly negative correlation with soil moisture in five vegetation types with R2 ranging from 0.55 to 0.93. Further analysis indicated the positive linear correlation between Rs rate and wind speed. Principal component analysis showed that soil temperature and moisture in the top 0-60 cm layer of the soil are the first-line impact factors for Rs rate in five vegetation types. The temperature and moisture in surface soil are the second main impact factor, and solar radiation is the third main factor to affect Rs rate. The results indicate that Rs was significantly different in different vegetation types, and changes in vegetation alter the pattern of the Rs rate. This study has important implications as it helps to understand the role that different vegetation types play in reduction of carbon emission. Such information will lay a foundation for assessing carbon source or carbon sequestration of different vegetation types in Qilian mountainous area. 参考文献 相似文献 引证文献