Ma Xin-Xin, Zhao Yun-Ge, Ma Ning, Li Wen, Sun Hui, Xu Ming-Xiang
Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China.
Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2022 Jan;33(1):67-75. doi: 10.13287/j.1001-9332.202201.007.
Grazing is an important driving factor for soil carbon sequestration in grasslands. The objective of this study was to clarify the effects of grazing and its intensity on soil organic carbon stocks (SOCS) in the revegetated grasslands in the Loess Plateau region. With the grasslands excluded from grazing ＞20 years as the control, we investigated the SOCS in the 0-20 cm soil layer in three grazing intensities in the west, middle, and east of wind-water erosion crisscross region and the water erosion region. The intensity of grazing in the study was represented by the number of goat dung in the sampling sites, which included 0-10, 10-20, and more than 20 goat dung·m, respectively. Results showed that grazing significantly affected SOCS in the 0-20 cm soil layer in the west of crisscross region, 0-10 cm soil layer in the east of crisscross region, and 0-5 cm soil layer in the water erosion region. There was no significant effect in each soil layer in the middle of crisscross region. Only in the west of crisscross region, the SOCS in the grazing intensity of 0-10 and ＞20 goat dung·m significantly decreased by 34.8%-50.9%, whereas the SOCS in each grazing intensity was not different from that in the enclosure in the other three regions. The SOCS was mainly affected by grazing intensity in the east of crisscross region and by soil physical and chemical properties and (or) litter biomass in the other three regions. In conclusion, grazing intensity of 10-20 goat dung·m did not affect SOCS in the 0-20 cm soil layer in the revegetated grassland on the Loess Plateau, China.
放牧是草原土壤碳固存的重要驱动因素。本研究的目的是阐明放牧及其强度对黄土高原地区植被恢复草原土壤有机碳储量（SOCS）的影响。以20多年未放牧的草原为对照，我们调查了风水蚀交错区西部、中部和东部以及水蚀区三种放牧强度下0-20厘米土层的SOCS。研究中的放牧强度以采样点山羊粪便数量表示，分别为0-10、10-20和超过20个山羊粪便·平方米。结果表明，放牧对交错区西部0-20厘米土层、交错区东部0-10厘米土层和水蚀区0-5厘米土层的SOCS有显著影响。交错区中部各土层均无显著影响。仅在交错区西部，0-10和＞20个山羊粪便·平方米放牧强度下的SOCS显著下降34.8%-50.9%，而其他三个区域各放牧强度下的SOCS与围栏内无差异。交错区东部的SOCS主要受放牧强度影响，其他三个区域则受土壤理化性质和（或）凋落物生物量影响。总之，10-20个山羊粪便·平方米的放牧强度对中国黄土高原植被恢复草原0-20厘米土层的SOCS没有影响。
