Abstract：
Protists, a crucial part of the soil food web, are increasingly acknowledged as significant influencers of nutrient cycling and plant performance in farmlands. While topographical and climatic factors are often considered to drive microbial communities on a continental scale, higher trophic levels like heterotrophic protists also rely on their food sources. In this context, bacterivores have received more attention than fungivores. Our study explored the connection between the community composition of protists (specifically Rhizaria and Cercozoa) and fungi across 156 cereal fields in Europe, spanning a latitudinal gradient of 3000 km. We employed a machine-learning approach to measure the significance of fungal communities in comparison to bacterial communities, soil abiotic factors, and climate as determinants of the Cercozoa community composition. Our findings indicate that climatic variables and fungal communities are the primary drivers of cercozoan communities, accounting for 70% of their community composition. Structural equation modelling (SEM) unveiled indirect climatic effects on the cercozoan communities through a change in the composition of the fungal communities. Our data also imply that fungivory might be more prevalent among protists than generally believed. This study uncovers a hidden facet of the soil food web, suggesting that the benefits of microbial diversity could be more effectively integrated into sustainable agriculture practices.
摘要：
原生生物,土壤食物网的关键部分，越来越被认为是农田养分循环和植物性能的重要影响者。虽然地形和气候因素通常被认为在大陆尺度上驱动微生物群落，更高的营养水平，如异养原生生物也依赖于他们的食物来源。在这种情况下，细菌比真菌受到更多的关注。我们的研究探索了欧洲156个谷物田的原生生物（特别是根瘤菌和Cercozoa）的群落组成与真菌之间的联系，跨越3000公里的纬度梯度。我们采用了机器学习方法来测量真菌群落与细菌群落相比的重要性。土壤非生物因素，和气候是Cercozoa群落组成的决定因素。我们的发现表明，气候变量和真菌群落是cercozoan群落的主要驱动因素，占其社区组成的70%。结构方程模型（SEM）通过真菌群落组成的变化揭示了气候对cercozoan群落的间接影响。我们的数据还暗示，在原生生物中，真菌可能比人们普遍认为的更为普遍。这项研究揭示了土壤食物网的一个隐藏的方面，这表明微生物多样性的好处可以更有效地整合到可持续农业实践中。
