Wang Yingxin, Wu Zhe, Wang Zhaofeng, Chang Shenghua, Qian Yongqiang, Chu Jianmin, Jia Zhiqing, Zhou Qingping, Hou Fujiang
State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Front Plant Sci. 2022 Mar 4;13:839920. doi: 10.3389/fpls.2022.839920. eCollection 2022.
Most alpine meadow on the Tibetan Plateau are at different stages of community succession induced by grazing practices. Quantifying the succession sequence and assessing the dynamics of plant composition, ecosystem coupling, and multifunctionality across successional stages are essential for reasonable restoration of degraded alpine meadow. Here, we selected areas with different grazing disturbance histories and used them as a space series (i.e., space-for-time substitution) to study the community succession. Our work quantified the plant succession sequence of alpine meadow induced by grazing with plant functional group approach. The plant succession sequence is from the tall sedge community with erect growth to the short undesirable toxic forbs community with prostrate growth. Ecosystem coupling, ecosystem multifunctionality and their relationships were all the lowest in Stage 4. Compared to Stage 4, the ecosystem multifunctionality index increased in Stages 1, 2, and 3 by 102.6, 89.8, and 207.6%, respectively; the extent of ecosystem coupling increased by 20.0, 16.8, and 21.2%, respectively. Our results indicated that the driving factors of ecosystem coupling and ecosystem multifunctionality were soil factor individual in early successional stage to plant-soil simultaneously in late successional stage. Our results also highlighted the importance of toxic weeds during the late stage of degraded succession and suggest that the expansion of toxic plants is a consequence of their greater suitability from a successional perspective. The findings of this study would provide valuable guidance for optimizing the management and restoration practice of alpine meadow.
青藏高原上的大多数高山草甸处于放牧导致的群落演替的不同阶段。量化演替序列并评估不同演替阶段植物组成、生态系统耦合和多功能性的动态变化，对于合理恢复退化的高山草甸至关重要。在此，我们选择了具有不同放牧干扰历史的区域，并将其作为空间序列（即空间换时间替代法）来研究群落演替。我们的工作采用植物功能群方法量化了放牧引起的高山草甸植物演替序列。植物演替序列是从直立生长的高莎草群落到匍匐生长的矮小有害有毒杂草群落。生态系统耦合、生态系统多功能性及其关系在第4阶段均为最低。与第4阶段相比，生态系统多功能性指数在第1、2和3阶段分别增加了102.6%、89.8%和207.6%；生态系统耦合程度分别增加了20.0%、16.8%和21.2%。我们的结果表明，生态系统耦合和生态系统多功能性的驱动因素在演替早期是土壤因素单独作用，在演替后期是植物 - 土壤共同作用。我们的结果还突出了有毒杂草在退化演替后期的重要性，并表明有毒植物的扩张是从演替角度来看它们更具适应性的结果。本研究结果将为优化高山草甸的管理和恢复实践提供有价值的指导。
