An increasing number of studies of above‐belowground interactions provide a fundamental basis for our understanding of the coexistence between plant and soil communities. However, we lack empirical evidence to understand the directionality of drivers of plant and soil communities under natural conditions: ‘Are soil microorganisms driving plant community functioning or do they adapt to the plant community?’ In a field experiment in an early successional dune ecosystem, we manipulated soil communities by adding living (i.e., natural microbial communities) and sterile soil inocula, originating from natural ecosystems, and examined the annual responses of soil and plant communities. The experimental manipulations had a persistent effect on the soil microbial community with divergent impacts for living and sterile soil inocula. The plant community was also affected by soil inoculation, but there was no difference between the impacts of living and sterile inocula. We also observed an increasing convergence of plant and soil microbial composition over time. Our results show that alterations in soil abiotic and biotic conditions have long‐term effects on the composition of both plant and soil microbial communities. Importantly, our study provides direct evidence that soil microorganisms are not “drivers” of plant community dynamics. We found that soil fungi and bacteria manifest different community assemblies in response to treatments. Soil fungi act as “passengers,” that is, soil microorganisms reflect plant community dynamics but do not alter it, whereas soil bacteria are neither “drivers” nor “passengers” of plant community dynamics in early successional ecosystems. These results are critical for understanding the community assembly of plant and soil microbial communities under natural conditions and are directly relevant for ecosystem management and restoration.

中文翻译：

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真菌群落是沙丘生态系统群落发展的过客，而细菌则不是


越来越多的地上地下相互作用的研究为我们理解植物和土壤群落的共存提供了基础基础。然而，我们缺乏经验证据来理解自然条件下植物和土壤群落驱动因素的方向性：“土壤微生物是驱动植物群落功能还是它们适应植物群落？”在早期演替沙丘生态系统的田间实验中，我们通过添加源自自然生态系统的活体（即天然微生物群落）和无菌土壤接种物来操纵土壤群落，并检查土壤和植物群落的年度反应。实验操作对土壤微生物群落具有持续影响，对活土壤接种物和无菌土壤接种物具有不同的影响。植物群落也受到土壤接种的影响，但活菌和无菌接种的影响没有差异。我们还观察到随着时间的推移，植物和土壤微生物组成越来越趋同。我们的结果表明，土壤非生物和生物条件的变化对植物和土壤微生物群落的组成具有长期影响。重要的是，我们的研究提供了直接证据，表明土壤微生物不是植物群落动态的“驱动因素”。我们发现土壤真菌和细菌对处理的反应表现出不同的群落组合。土壤真菌充当“乘客”，即土壤微生物反映植物群落动态但不改变它，而土壤细菌既不是早期演替生态系统中植物群落动态的“驱动者”也不是“乘客”。 这些结果对于了解自然条件下植物和土壤微生物群落的群落组装至关重要，并且与生态系统管理和恢复直接相关。