Soil Arbuscular Mycorrhizal Fungi Metagenome. soil metagenome

Biological invasions are a major factor contributing to global change and ecosystem degradation. Many of the harmful effects of biological invasions are caused by alterations in the richness and abundance of native versus invasive organisms. However, the effects of invasive species on the diversity of native biota are often scale-dependent and may show opposing trends at different spatial extents. For obligately symbiotic organisms such as arbuscular-mycorrhizal fungi (AMF), the effects of plant invasions on their diversity remain largely unknown. To examine possible scale-dependent changes in AMF with plant invasions, we sampled AMF across spatial gradients and used hierarchical modeling to relate species richness to area. Our results show that AMF have a species-area relationship similar to many macroorganisms and that biological invasions decrease species richness at small spatial scales. These results provide some of the first evidence of the scale-dependent and effects of invasions on microbial mutualist diversity.

生物入侵是驱动全球变化与生态系统退化的核心因素之一。生物入侵所引发的诸多有害效应，源于本土与入侵生物的物种丰富度及个体多度发生改变。然而，入侵物种对本土生物群落多样性的影响往往具有尺度依赖性，在不同空间尺度下可能呈现截然相反的变化趋势。对于丛枝菌根真菌（arbuscular-mycorrhizal fungi, AMF）这类专性共生生物而言，植物入侵对其多样性的影响目前仍知之甚少。为探究植物入侵驱动下丛枝菌根真菌多样性可能存在的尺度依赖性变化，我们在空间梯度上开展了丛枝菌根真菌样本采集，并通过层级模型将物种丰富度与采样面积进行关联分析。研究结果显示，丛枝菌根真菌具备与多数大型生物相似的物种-面积关系，且植物入侵在小空间尺度下会降低其物种丰富度。本研究为揭示生物入侵对微生物共生生物多样性的尺度依赖性影响提供了首批实证依据。