Changes in plant assemblages can influence biotic and abiotic soil conditions. These changes can cause plant–soil feedbacks that can inhibit or facilitate plant germination and growth. Here, we contribute to a growing literature examining plant–soil feedbacks in the endangered sage scrub ecosystem by examining the germination and growth of Artemisia californica, the dominant native shrub species in the ecosystem, in soil conditioned by two widespread plant invaders (Brassica nigra, Bromus madritensis ssp. rubens), and the germination and growth of these invasive species in conspecific and heterospecific soils. Our findings suggest that: (i) A. californica soils can limit establishment of some species (B. nigra) but not others (B. madritensis), (ii) A. californica soil conditions reduce growth of all plant species, and (iii) non-natives are negatively impacted by soil microbes, but in some contexts can do better in heterospecific soil. As our findings were often incongruent with other studies that examined interactions among similar species at other sites, we suggest that we are at our infancy of understanding these complex interactions, and that developing a predictive framework for understanding plant soil feedbacks in the sage scrub ecosystem involves understanding how various plant species respond in different soil contexts within the ecosystem.

中文翻译：

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植物-土壤反馈对南加州常见的本地和非本地物种发芽和生长的影响

植物组合的变化会影响生物和非生物的土壤状况。这些变化会导致植物-土壤的反馈，从而抑制或促进植物的发芽和生长。在这里，我们促成越来越多的研究通过检查的萌发和生长研究的濒危圣人灌木丛生态系统植物-土壤反馈蒿丫，在生态系统中占主导地位的原生灌木树种，土壤由两个普遍的植物入侵者（空调，黑芥，马德雀麦SSP。鲁），并在同种和异种的土壤的萌发和这些入侵物种的生长。我们的发现表明：（i）加州土壤可以限制某些物种的建立（B. nigra）而非其他（B. madritensis），（ii）加州土壤土壤条件会降低所有植物的生长，并且（iii）非本地人受到土壤微生物的负面影响，但在某些情况下可以做得更好异种土壤。由于我们的发现通常与其他研究在其他地点的相似物种之间的相互作用的研究不一致，因此我们建议我们尚处于了解这些复杂相互作用的初期阶段，并且开发一种预测框架以了解鼠尾草灌木丛生态系统中的植物土壤反馈涉及了解各种植物物种如何在生态系统内的不同土壤环境中做出反应。