Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving Fertilizers, Laboratory of Bio-interactions and Crop Health, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China.
Laboratorio de Biodiversidad y Funcionamiento Ecosistemico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes 10, E-41012, Sevilla, Spain; Unidad Asociada CSIC-UPO (BioFun), Universidad Pablo de Olavide, 41013 Sevilla, Spain.
Sci Total Environ. 2022 Jul 1;828:154405. doi: 10.1016/j.scitotenv.2022.154405. Epub 2022 Mar 8.
Pedogenesis determines soil physicochemical properties and many biodiversity facets, including belowground microbial bacteria and fungi. At the local scale, top-down predation by microbial protists regulates the soil microbiome, while the microbiome also affects protistan communities. However, it remains unknown how pedogenesis affects protistan communities and the potential protist-microbiome predator-prey relationships. With 435 soil samples representing different stages of pedogenesis ranging in soil age from centuries to millennia, we examined the influence of pedogenesis on the main protistan groups, and the interrelationships between protistan predators and microbial prey biomass. We revealed an enrichment in the diversity of total protists across pedogenesis and increasing richness of phototrophic protists in the medium compared with the early stages of pedogenesis. The richness of predatory protists accumulated throughout pedogenesis, which was more strongly determined by microbial biomass than environmental factors. Predator-prey associations were stronger in the young and the medium soils than in the older soils, likely because prey biomass accumulated in the latter and might be no longer limit predators. Together, our work provides evidence that pedogenesis shapes predatory protists differently than their prey, leading to shifts in predator-prey relationships. This knowledge is critical to better understand how soil food webs develop across soil development which might lead to changes in ecosystem functions.
成土作用决定了土壤的物理化学性质和许多生物多样性方面，包括地下微生物细菌和真菌。在局部尺度上，微生物原生动物的自上而下捕食作用调节了土壤微生物组，而微生物组也影响着原生动物群落。然而，成土作用如何影响原生动物群落以及潜在的原生动物-微生物捕食者-猎物关系尚不清楚。本研究利用 435 个土壤样本，这些样本代表了从几百年到几千年不等的不同成土阶段，我们研究了成土作用对主要原生动物类群的影响，以及原生动物捕食者和微生物猎物生物量之间的相互关系。我们发现，在整个成土过程中，总原生动物的多样性不断增加，与早期相比，中光营养型原生动物的丰富度也在增加。捕食性原生动物的丰富度在整个成土过程中逐渐积累，这更多地取决于微生物生物量，而不是环境因素。在年轻和中等土壤中，捕食者-猎物的关联比在较老的土壤中更强，这可能是因为猎物生物量在后者中积累，可能不再限制捕食者。总之，我们的研究结果表明，成土作用对捕食性原生动物的塑造方式不同于其猎物，导致捕食者-猎物关系发生变化。这一知识对于更好地理解土壤食物网如何在土壤发育过程中发展至关重要，这可能导致生态系统功能发生变化。
