AMF communities in soil of grasslands of differing age (deltaBEF)

The link between biodiversity and ecosystem functioning strengthens with ecosystem age. Arbuscular mycorrhizal are a potential driver, due to their role in plant survival and niche exploration. We study the development of AMF communities in the long-time biodiversity Jena Experiment. Nested within the pre-existing grasslands of varying plant diversity, subplots with combinations of common plant and soil histories were established: grassland plots with neither plant nor soil history, with only soil history, and with both plant and soil history. We found that bulk soil AMF communities were determined rather by soil history than by plant history. In monocultures of different plant species, AMF communities became more alike with common history, while in more diverse grasslands the AMF communities did not significantly converge or diverge over time. Our hypothesis that AM fungal communities might shift from mainly generalists to more specialists over time could not be confirmed. Communities in grasslands with plant or soil history were more similar to each other than to plots without any common history. Claroideoglomus showed tendencies of higher abundance in grasslands with soil history, while Paraglomus seemed to decrease in abundance over time. We found no interactive effect of plant diversity and history treatment.

生物多样性与生态系统功能之间的关联随生态系统存续时长增加而增强。丛枝菌根真菌（Arbuscular Mycorrhizal Fungi, AMF）是潜在的驱动因子，因其在植物存活与生态位开拓中发挥关键作用。本研究依托长期生物多样性研究平台耶拿试验田（Jena Experiment），探究AMF群落的演替规律。研究嵌套于原有不同植物多样性的草地生态系统中，设置了包含不同植物起源与土壤起源组合的亚样地：包括既无植物起源也无土壤起源的草地样地、仅具土壤起源的样地，以及兼具植物与土壤起源的样地。研究发现，原状土壤中的AMF群落主要受土壤起源影响，而非植物起源。在单一植物物种的栽培样地中，具有共同起源的AMF群落相似度随时间提升；而在植物多样性更高的草地样地中，AMF群落并未随时间发生显著的趋同或趋异变化。我们提出的"AMF群落随时间从广适性类群向专化性类群转变"的假说未得到验证。具有植物起源或土壤起源的草地样地中的AMF群落，彼此间的相似度高于与无任何共同起源样地的群落相似度。类球囊霉属（Claroideoglomus）在具土壤起源的草地样地中呈现丰度升高的趋势，而副球囊霉属（Paraglomus）的丰度则随时间呈下降趋势。本研究未发现植物多样性与起源处理之间存在交互效应。