Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.
Center of the Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China.
Mol Ecol. 2021 May;30(10):2390-2403. doi: 10.1111/mec.15882. Epub 2021 Mar 27.
Disentangling the biogeographic patterns of rare and abundant microbes is essential in order to understand the generation and maintenance of microbial diversity with respect to the functions they provide. However, little is known about ecological assembly processes and environmental adaptation of rare and abundant microbes across large spatial-scale wetlands. Using Illumina sequencing and multiple statistical analyses, we characterized the taxonomic and phylogenetic diversity of rare and abundant bacteria and fungi in Qinghai-Tibet Plateau wetland soils. Abundant microbial taxa exhibited broader environmental thresholds and stronger phylogenetic signals for ecological traits than rare ones. By contrast, rare taxa showed higher sensitivity to environmental changes and closer phylogenetic clustering than abundant ones. The null model analysis revealed that dispersal limitation belonging to stochastic process dominated community assemblies of abundant bacteria, and rare and abundant fungi, while variable selection belonging to deterministic process governed community assembly of rare bacteria. Neutral model analysis and variation partitioning analysis further confirmed that abundant microbes were less environmentally constrained. Soil ammonia nitrogen was the crucial factor in mediating the balance between stochasticity and determinism of both rare and abundant microbes. Abundant microbes may have better environmental adaptation potential and are less dispersed by environmental changes than rare ones. Our findings extend knowledge of the adaptation of rare and abundant microbes to ongoing environmental change and could facilitate prediction of biodiversity loss caused probably by climate change and human activity in the Qinghai-Tibet Plateau wetlands.
为了了解稀有微生物和丰富微生物在其功能方面的产生和维持，解析稀有微生物和丰富微生物的生物地理模式至关重要。然而，人们对稀有微生物和丰富微生物在大尺度湿地中的生态组装过程和环境适应性知之甚少。本研究利用 Illumina 测序和多种统计分析方法，描述了青藏高原湿地土壤中稀有和丰富细菌和真菌的分类和系统发育多样性。丰富的微生物类群表现出更宽的环境阈值和更强的生态特征系统发育信号，而稀有类群则表现出对环境变化的更高敏感性和更密切的系统发育聚类。零模型分析表明，扩散限制属于随机过程主导着丰富细菌、稀有和丰富真菌群落的组装，而可变选择属于确定性过程主导着稀有细菌群落的组装。中性模型分析和变异划分分析进一步证实，丰富的微生物受到的环境限制较小。土壤氨氮是调节稀有微生物和丰富微生物的随机性和确定性平衡的关键因素。丰富的微生物可能具有更好的环境适应潜力，并且比稀有微生物受环境变化的影响更小。本研究结果扩展了稀有微生物和丰富微生物对持续环境变化的适应知识，并有助于预测可能由气候变化和人类活动引起的青藏高原湿地生物多样性丧失。
