Zhao Yanyun, Ding Yong, Hou Xiangyang, Li Frank Yonghong, Han Wenjun, Yun Xiangjun
School of Ecology and Environment, Inner Mongolia University/Inner Mongolia Key Laboratory of Grassland Ecology, Hohhot, China.
Grassland Research Institute of the Chinese Academy of Agricultural Sciences/ Key Laboratory of Grassland Ecology and Restoration of the Ministry of Agriculture, Hohhot, China.
PLoS One. 2017 Oct 30;12(10):e0186980. doi: 10.1371/journal.pone.0186980. eCollection 2017.
Soil represents the largest terrestrial organic carbon pool. To address global climate change, it is essential to explore the soil organic carbon storage patterns and their controlling factors. We investigated the soil organic carbon density (SOCD) in 48 grassland sites along the Eurasian steppe eastern transect (ESET) region, which covers the Inner Mongolia grassland subregion and Mongolia grasslands subregion. Specifically, we analyzed the SOCD in the top 30 cm soil layer and its relationships with climatic variables, soil texture, grazing intensity and community biomass productivity. The results showed that the average SOCD of the ESET was 4.74 kg/m2, and the SOCD of the Inner Mongolia grassland subregion (4.11 kg/m2) was significantly lower than that of the Mongolia grassland subregion (5.79 kg/m2). Significant negative relationships were found between the SOCD and the mean annual temperature (MAT), mean annual precipitation (MAP) and grazing intensity in the ESET region. The MAT and grazing intensity were identified as the major factors influencing the SOCD in the ESET region; the MAP and MAT were the major factors influencing the SOCD in the Inner Mongolia grassland subregion; and the MAT and soil pH were the major factors influencing the SOCD in the Mongolia grassland subregion.
土壤是最大的陆地有机碳库。为应对全球气候变化，探索土壤有机碳储存模式及其控制因素至关重要。我们调查了欧亚草原东部样带（ESET）区域48个草原站点的土壤有机碳密度（SOCD），该区域涵盖内蒙古草原亚区域和蒙古草原亚区域。具体而言，我们分析了0至30厘米土层的SOCD及其与气候变量、土壤质地、放牧强度和群落生物量生产力的关系。结果表明，ESET的平均SOCD为4.74千克/平方米，内蒙古草原亚区域的SOCD（4.11千克/平方米）显著低于蒙古草原亚区域（5.79千克/平方米）。在ESET区域，SOCD与年平均温度（MAT）、年平均降水量（MAP）和放牧强度之间存在显著负相关关系。MAT和放牧强度被确定为影响ESET区域SOCD的主要因素；MAP和MAT是影响内蒙古草原亚区域SOCD的主要因素；MAT和土壤pH值是影响蒙古草原亚区域SOCD的主要因素。
