Plant competition alters the temporal dynamics of plant-soil feedbacks

1. Most studies on plant-soil feedback (PSF) and plant competition measure the feedback response at one moment only. However, PSFs and competition may both change over time, and how PSF and competition interact over time is unclear. 2. We tested the temporal dynamics of PSF and interspecific competition for the forb Jacobaea vulgaris and the grass Holcus lanatus. We grew both species individually and in interspecific competition in soil that was first conditioned in the greenhouse by J. vulgaris, by H. lanatus or without plant growth. For a period of 11 weeks, we harvested plants twice a week and analyzed the fungal and chemical composition of the different soils at the end of the first and second growth phase. 3. During the second growth phase, when grown in isolation, both species produced more biomass in heterospecific conditioned soil than in conspecific conditioned soil. Young J. vulgaris exhibited a strong negative conspecific feedback, but this effect diminished over time and bec...1. 现有关于植物-土壤反馈（plant-soil feedback, PSF）与植物竞争的研究，大多仅在单一时间点测定反馈响应。然而，植物-土壤反馈与种间竞争均可能随时间发生动态变化，二者随时间的相互作用机制目前仍不明晰。 2. 本研究针对阔叶草本千里光（Jacobaea vulgaris）与禾本科草本绒毛草（Holcus lanatus），探究植物-土壤反馈与种间竞争的时间动态特征。我们将两个物种分别以单种种植以及种间竞争组合的方式，种植于经植物培育的土壤中：这些土壤先在温室中由千里光、绒毛草单独培育，或未种植任何植物作为空白对照。在为期11周的实验周期内，我们每周进行两次植物收获，并在第一、第二生长阶段结束时，分析不同土壤的真菌群落组成与化学特性。 3. 在第二生长阶段中，两个物种单种种植时，在异种培育土壤中的生物量均高于同种培育土壤。幼龄千里光表现出强烈的同种负反馈效应，但该效应随时间推移逐渐减弱并...