内蒙古不同类型草原土壤团聚体含量的分配及其稳定性  

Allocation of mass and stability of soil aggregate in different types of Nei Mongol grasslands

作　　者：王甜 徐姗 赵梦颖 李贺[1,2] 寇丹 方精云 胡会峰[1] 

机构地区：[1]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093 [2]中国科学院大学,北京100049 [3]中国科学院华南植物园,广州510650

出　　处：《植物生态学报》2017年第11期1168-1176,共9页Chinese Journal of Plant Ecology

基　　金：国家重点基础研究发展计划(973计划)(2015CB954201和2014CB954303)

摘　　要：土壤团聚体是土壤结构的重要组成部分,是土壤保护其有机碳的一种重要物理与生物机制,但迄今为止对其空间格局分布的研究较少。该文研究了我国内蒙古3种草原类型(草甸草原、典型草原、荒漠草原)不同土层深度的土壤团聚体质量百分比及其稳定性的分布规律。结果显示:土壤团聚体的质量百分比在3种草原类型各个土层深度的分布均呈现草甸草原>典型草原=荒漠草原的趋势,而沿土层深度3种草原类型的土壤团聚体的质量百分比含量并未呈现显著规律。各层的土壤团聚体质量百分比均与年降水量呈显著正相关关系;除70–100 cm土层外,其与年平均气温均呈负相关关系。对土壤团聚体稳定性而言,在0–10 cm和10–20 cm两个土层深度,草甸草原土壤团聚体的平均质量直径与几何平均直径显著大于典型草原和荒漠草原,而在其他土层,3种草原类型间无显著差异。随着土层深度的增加,草甸草原和典型草原土壤团聚体的平均质量直径与几何平均直径均呈现逐渐降低的趋势。该文对于理解内蒙古不同类型草原土壤有机碳的稳定性和保护机制具有重要意义。Aims Soil aggregate is an important component of soil structure, playing an important role in the physical and biological protection mechanism of soil organic carbon （SOC） through isolating SOC from microorganisms. As far as we know, there are few studies, however, on exploring the spatial distribution of soil aggregate at the re- gional scale. Our objective was to investigate the mass allocation and stability of soil aggregate in different types of Nei Mongol grasslands. Methods We have established 78 sites with a size of 10 m ~ 10 m across the transect of Nei Mongol grasslands and collected soil samples from different soil depth up to 1 m. We used wet sieving method to separate different sizes of aggregate partition and used mean mass diameter （MMD） and geometric mean diameter （GMD） in order to evaluate the stability of soil aggregate. The two-way ANOVA was used to test the difference of mass percentage and stability of soil aggregate in different grassland types and soil depths. In addition, a linear regression analysis was used to analyze the correlations of mass percentage and stability of soil aggregate with both mean annual pre- cipitation （MAP） and mean annual temperature （MAT）. Important findings The results showed that the mass percentages of soil aggregate were highest in meadow steppe, while almost equal in typical steppe and desert steppe. However, no significant patterns were found along the soil depth. The mass percentage of soil aggregate fractions were positively correlated with MAP in all soil layers, but negatively correlated with MAT except the layer of 70-100 cm. For the stability of soil aggregate, at 0-10 and 10-20 cm, MMD and GMD of meadow steppe were significantly greater than those of typical and desert steppes, whereas no significant differences among three grassland types were found for other soil layers. Besides, MMD and GMD in meadow steppe and typical steppe gradually decreased along the soil depth.

关 键 词：内蒙古草原 土壤团聚体质量百分比 土壤团聚体稳定性 土层深度 气候因子 

分 类 号：S812.2[农业科学—草业科学]