Xu Yuting, Cui Ke, Zhang Xiaoshan, Diwu Guodong, Zhu Yuanjun, Deng Lei, Zhong Yangquanwei, Yan Weiming
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi, China.
Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China.
mBio. 2025 Mar 12;16(3):e0283424. doi: 10.1128/mbio.02834-24. Epub 2025 Jan 24.
Soil microbial diversity and community life strategies are crucial for nutrient cycling during vegetation restoration. Although the changes in topsoil microbial communities during restoration have been extensively studied, the structure, life strategies, and function of microbial communities in the subsoil remain poorly understood, especially regarding their role in nutrient cycling during vegetation restoration. In this study, we conducted a comprehensive investigation of the changes in the soil microbial community, assembly process, life strategies, and nutrient cycling functional genes in soil profiles (0-100 cm) across a 36 year chronosequence (5, 15, 28, and 36 years) of fenced grassland and one grazing grassland on the Loess Plateau of China. Our results revealed that soil organic carbon increased by 76.0% in topsoil and 91.6% in subsoil after 36 years of restoration. The bacterial communities were influenced primarily by soil depth, while the fungal communities were highly sensitive to the years of restoration. Microbes in the subsoil recovered faster, and the microbial community structure and functional genes in the soil profiles gradually became more consistent following restoration. In addition, we observed a transition in microbial life history strategies from a persistent -strategy to a rapid -strategy during restoration. Notably, the fungal community assembly process played an important role in changes in nutrient cycling genes, which were accompanied by increased carbon fixation and nitrogen mineralization function. Overall, our findings provide several novel insights into the impact of changes in the fungal community on soil nutrient cycling in the soil profile during vegetation restoration.IMPORTANCEOur study revealed that microbes in the subsoil recovered faster than those in the topsoil, which contributed to the reduction in differences in microbial community structure and the distribution of functional genes throughout the soil profile during the restoration process. Importantly, the assembly of fungal communities plays a pivotal role in driving changes in nutrient cycling genes, such as increased carbon fixation and nitrogen mineralization, alongside a reduction in carbon degradation gene abundance. These alterations increase soil organic carbon and nutrient availability during restoration. Our results increase the understanding of the critical role of fungal communities in soil nutrient cycling genes, which facilitate nutrient accumulation in soil profiles during grassland restoration. This insight can guide the development of strategies for manipulating fungal communities to increase soil nutrients in grasslands.
土壤微生物多样性和群落生活策略对于植被恢复过程中的养分循环至关重要。尽管恢复过程中表层土壤微生物群落的变化已得到广泛研究，但对亚表层土壤微生物群落的结构、生活策略和功能仍知之甚少，尤其是它们在植被恢复过程中对养分循环的作用。在本研究中，我们对中国黄土高原围栏草地和一块放牧草地的36年时间序列（5年、15年、28年和36年）土壤剖面（0-100厘米）中的土壤微生物群落变化、组装过程、生活策略和养分循环功能基因进行了全面调查。我们的结果表明，经过36年的恢复，表层土壤有机碳增加了76.0%，亚表层土壤增加了91.6%。细菌群落主要受土壤深度影响，而真菌群落对恢复年限高度敏感。亚表层土壤中的微生物恢复得更快，恢复后土壤剖面中的微生物群落结构和功能基因逐渐变得更加一致。此外，我们观察到恢复过程中微生物生活史策略从持久性策略向快速性策略的转变。值得注意的是，真菌群落组装过程在养分循环基因的变化中起重要作用，同时伴随着碳固定和氮矿化功能的增加。总体而言，我们的研究结果为植被恢复过程中真菌群落变化对土壤剖面土壤养分循环的影响提供了一些新的见解。重要性我们的研究表明，亚表层土壤中的微生物比表层土壤中的微生物恢复得更快，这有助于减少恢复过程中整个土壤剖面微生物群落结构和功能基因分布的差异。重要的是，真菌群落的组装在驱动养分循环基因的变化中起关键作用，例如碳固定增加和氮矿化增加，同时碳降解基因丰度降低。这些变化在恢复过程中增加了土壤有机碳和养分有效性。我们的结果增进了对真菌群落在土壤养分循环基因中的关键作用的理解，这有助于草地恢复过程中土壤剖面中的养分积累。这一见解可以指导制定操纵真菌群落以增加草地土壤养分的策略。
