Background and AimsPlants affect the soil environment via litter inputs and changes in biotic communities, which feed back to subsequent plant growth. Here we investigated the individual contributions of litter and biotic communities to soil feedback effects, and plant ability to respond to spatial heterogeneity in soil legacy.MethodsWe tested for localised and systemic responses of Trifolium repens to soil biotic and root litter legacy of seven grassland species by exposing half of a root system to control soil and the other half to specific inoculum or root litter.ResultsSoil inoculation triggered a localised reduction in root length while litter locally increased root biomass independent of inoculum or litter species identity. Nodule formation was locally suppressed in response to soil conditioned by another legume (Vicia cracca) and showed a trend towards systemic reduction in response to conspecific soil. V. cracca litter also caused a systemic response with thinner roots produced in the part of the root system not directly exposed to the litter.ConclusionsSpatial heterogeneity in root litter distribution and soil communities generate distinct local and systemic responses in root morphology and nodulation. These responses can influence plant-mutualist interactions and nutrient cycling, and should be included in plant co-existence models.

中文翻译：

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根凋落物和土壤遗产的空间异质性对豆科植物根部性状有不同影响

背景和目标植物通过凋落物输入和生物群落的变化影响土壤环境，从而反馈到随后的植物生长。在这里，我们研究了凋落物和生物群落对土壤反馈效应的个体贡献，以及植物对土壤遗留物空间异质性的反应能力。方法我们通过以下方法测试了白三叶草对土壤生物和根凋落物遗留物的局部和系统反应：将根系的一半暴露于土壤中，另一半暴露于特定的接种物或根凋落物中。结果土壤接种引发了根长的局部减少，而凋落物局部增加了根生物量，与接种物或凋落物的物种特性无关。根瘤形成因受到另一种豆科植物（Vicia cracca）调节的土壤而受到局部抑制，并显示出因同种土壤而系统减少的趋势。V. cracca凋落物还引起了系统反应，在未直接暴露于凋落物的根系部分中产生了较细的根。结论根凋落物分布和土壤群落的空间异质性在根形态和结瘤方面产生不同的局部和系统反应。这些反应可以影响植物互利相互作用和养分循环，应包含在植物共存模型中。