The relationship between biodiversity and ecosystem functioning strengthens with ecosystem age. However, the interplay between the plant diversity - ecosystem functioning relationship and Glomeromycotinian arbuscular mycorrhizal fungi (AMF) community assembly has not yet been scrutinized in this context, despite AMF’s role in plant survival and niche exploration. We study the development of AMF communities by disentangling soil- and plant-driven effects from calendar year effects. Within a long-term grassland biodiversity experiment, the pre-existing plant communities of varying plant diversity were re-established as split plots with combinations of common plant and soil histories: split plots with neither common plant nor soil history, with only soil but no plant history, and with both common plant and soil history. We found that bulk soil AMF communities were primarily shaped by common soil history, and additional common plant history had little effect. Further, the steepness of AMF diversity and plant diversity relationship did not strengthen over time, but AMF community evenness increased with common history. Specialisation of AMF towards plant species was low throughout, giving no indication of AMF communities specialising or diversifying over time. The potential of bulk soil AMF as mediators of variation in plant and microbial biomass over time and hence as drivers of biodiversity and ecosystem relationships was low. Our results suggest that soil processes may be key for the build-up of plant community-specific mycorrhizal communities with likely feedback effects on ecosystem productivity, but the plant-available mycorrhizal pool in bulk soil itself does not explain the strengthening of biodiversity and ecosystem relationships over time.

生物多样性和生态系统功能之间的关系随着生态系统年龄的增长而加强。然而，尽管 AMF 在植物生存和生态位探索中发挥着重要作用，但植物多样性 - 生态系统功能关系与肾分枝菌根真菌 (AMF) 群落组装之间的相互作用尚未得到仔细研究。我们通过将土壤和植物驱动的影响与历年影响分开来研究 AMF 群落的发展。在一项长期的草原生物多样性实验中，不同植物多样性的现有植物群落被重新建立为具有常见植物和土壤历史组合的裂区：既没有共同植物也没有土壤历史的裂区，只有土壤但没有土壤。植物历史，以及常见的植物和土壤历史。我们发现，大块土壤 AMF 群落主要是由共同的土壤历史形成的，而其他共同的植物历史几乎没有影响。此外，AMF多样性和植物多样性关系的陡峭度并没有随着时间的推移而加强，但AMF群落的均匀度随着共同历史的增加而增加。 AMF 对植物物种的专业化程度始终较低，没有迹象表明 AMF 群落随着时间的推移而专业化或多样化。大量土壤 AMF 作为植物和微生物生物量随时间变化的调节剂，从而作为生物多样性和生态系统关系的驱动因素的潜力很低。我们的结果表明，土壤过程可能是植物群落特异性菌根群落建立的关键，可能对生态系统生产力产生反馈影响，但散装土壤中植物可用的菌根库本身并不能解释生物多样性和生态系统关系的加强随着时间的推移。