不同放牧管理措施下张掖草地土壤有机碳储量时空统计分析

Spatiotemporal statistical analysis of soil organic carbon storage in Zhangye grassland under different grazing management measures

摘要:

【目的】 研究不同放牧管理措施对张掖草地土壤有机碳储量的影响，为实现草地可持续发展提供基础数据和科学依据。【方法】 使用本地化DAYCENT模型模拟1970-2022年张掖草地在无放牧管理措施和不同放牧管理措施（休牧围栏、轮牧围栏和退化草地改良）下土壤有机碳储量（SOCR）的时空分布。【结果】 参数本地化的DAYCENT模型有效模拟了张掖土壤有机碳的动态变化。草地土壤有机碳随时间推移而显著增加，不同放牧管理措施对土壤有机碳积累起到积极作用。空间上土壤有机碳储量呈现自西南向东北递增的分布格局，其中民乐县、高台县、肃南县东北部是土壤有机碳储量的高值区。【结论】 从长期发展来看，休牧围栏固碳能力强于轮牧围栏、退化草地改良，轮牧围栏以轻微的固碳优势高于退化草地改良。张掖草地管理可通过合理的放牧措施实现土壤长期固碳。

Abstract:

【Objective】 The objective of this study is to investigate the effects of different grazing management measures on soil organic carbon storage in Zhangye grassland and to provide essential data and scientific support for the sustainable development of grassland.【Method】 The spatiotemporal distribution of soil organic carbon storage （SOCR） in Zhangye grassland from 1970 to 2022 was simulated by using the localized DAYCENT model. Simulation was conducted no grazing management measures and various grazing management practices，including fallow grazing fence，rotational grazing fence，and degraded grassland improvement.【Result】 The DAYCENT model with parameter localization effectively simulated the dynamic changes insoil organic carbon in Zhangye. Soil organic carbon （SOC） increased significantly over time，and different grazing management practices positively influenced SOC accumulation. Spatially，soil organic carbon storage showed an increasing distribution pattern from southwest to northeast， with high-value areas of organic carbon storage were found in the northeast of Minle County，Gaotai County and Su- nan County.【Conclusion】 From the perspective of long-term development，the carbon sequestration capacity of fallow grazing fences is stronger than that of rotational grazing fences and degraded grassland improvement. The carbon sequestration advantage of rotational grazing fences is slightly higher than that of degraded grassland improvement. In terms of grassland management in Zhangye，long-term soil carbon sequestration can be achieved through reasonable grazing measures.