Plant–soil systems are key for understanding the effects of factors of global change. Recent work has highlighted the general importance of considering the simultaneous incidence of some factors or stressors. To help mechanistically dissect the possible interactions of such factors, we here propose three broad groups of mechanisms that may generally lead to nonadditivity of responses within a plant–soil system: direct factor interactions (that is one factor directly changing another), within-plant information processing and crosstalk, and effects of factors on groups of soil biota interacting with plants. Interactions are also possible within and across these groups. Factor interactions are very likely to be present in experiments, especially when dealing with an increasing number of factors. Identifying the nature of such interactions will be essential for understanding and predicting global change impacts on plants and soil.

中文翻译：

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支持植物-土壤系统中全球变化因子效应非可加性的机制

植物-土壤系统是了解全球变化因素影响的关键。最近的工作强调了考虑某些因素或压力源同时发生的重要性。为了帮助从机制上剖析这些因素的可能相互作用，我们在这里提出了三类机制，它们通常可能导致植物 - 土壤系统内响应的非可加性：直接因素相互作用（即一个因素直接改变另一个因素），植物内信息处理和串扰，以及因素对土壤生物群与植物相互作用的影响。这些群体内部和之间的互动也是可能的。实验中很可能会出现因子相互作用，尤其是在处理越来越多的因子时。