Ma Xinwei, Ren Baihui, Yu Jianxin, Wang Jiayu, Bai Long, Li Jiahuan, Li Daiyan, Meng Meng
College of Horticulture, Shenyang Agricultural University, Shenyang, Liaoning, China.
Front Microbiol. 2023 Jun 28;14:1205574. doi: 10.3389/fmicb.2023.1205574. eCollection 2023.
Soil microbial communities are critical in regulating grassland biogeochemical cycles and ecosystem functions, but the mechanisms of how environmental factors affect changes in the structural composition and diversity of soil microbial communities in different grassland soil types is not fully understood in northwest Liaoning, China.
We investigated the characteristics and drivers of bacterial and fungal communities in 4 grassland soil types with 11 sites across this region using high-throughput Illumina sequencing.
Actinobacteria and Ascomycota were the dominant phyla of bacterial and fungal communities, respectively, but their relative abundances were not significantly different among different grassland soil types. The abundance, number of OTUs, number of species and diversity of both bacterial and fungal communities in warm and temperate ecotone soil were the highest, while the warm-temperate shrub soil had the lowest microbial diversity. Besides, environmental factors were not significantly correlated with soil bacterial Alpha diversity index. However, there was a highly significant negative correlation between soil pH and Shannon index of fungal communities, and a highly significant positive correlation between plant cover and Chao1 index as well as Observed species of fungal communities. Analysis of similarities showed that the structural composition of microbial communities differed significantly among different grassland soil types. Meanwhile, the microbial community structure of temperate steppe-sandy soil was significantly different from that of other grassland soil types. Redundancy analysis revealed that soil total nitrogen content, pH and conductivity were important influencing factors causing changes in soil bacterial communities, while soil organic carbon, total nitrogen content and conductivity mainly drove the differentiation of soil fungal communities. In addition, the degree of connection in the soil bacterial network of grassland was much higher than that in the fungal network and soil bacterial and fungal communities were inconsistently limited by environmental factors. Our results showed that the microbial community structure, composition and diversity of different grassland soil types in northwest Liaoning differed significantly and were significantly influenced by environmental factors. Microbial community structure and the observation of soil total nitrogen and organic carbon content can predict the health changes of grassland ecosystems to a certain extent.
土壤微生物群落对调节草地生物地球化学循环和生态系统功能至关重要，但在中国辽宁西北部，不同草地土壤类型中环境因素如何影响土壤微生物群落结构组成和多样性变化的机制尚不完全清楚。
我们利用高通量Illumina测序技术，对该地区11个地点的4种草地土壤类型中的细菌和真菌群落特征及驱动因素进行了调查。
放线菌门和子囊菌门分别是细菌和真菌群落的优势门类，但它们在不同草地土壤类型中的相对丰度无显著差异。暖温交错带土壤中细菌和真菌群落的丰度、OTU数量、物种数量和多样性均最高，而暖温灌丛土壤的微生物多样性最低。此外，环境因素与土壤细菌α多样性指数无显著相关性。然而，土壤pH值与真菌群落的香农指数呈极显著负相关，植物盖度与真菌群落的Chao1指数及观测物种数呈极显著正相关。相似性分析表明，不同草地土壤类型间微生物群落的结构组成存在显著差异。同时，温带草原-沙地土壤的微生物群落结构与其他草地土壤类型显著不同。冗余分析表明，土壤全氮含量、pH值和电导率是导致土壤细菌群落变化的重要影响因素，而土壤有机碳、全氮含量和电导率主要驱动土壤真菌群落的分化。此外，草地土壤细菌网络的连接程度远高于真菌网络，且土壤细菌和真菌群落受环境因素的限制不一致。我们的结果表明，辽宁西北部不同草地土壤类型的微生物群落结构、组成和多样性存在显著差异，并受环境因素的显著影响。微生物群落结构以及土壤全氮和有机碳含量的观测在一定程度上可以预测草地生态系统的健康变化。
