Plant resource allocation strategies are thought to be largely a consequence of changing abiotic conditions and evolutionary history. However, biotic interactions also influence how a plant allocates resources. As a result, plants mediate indirect interactions between organisms above‐ and belowground through resource allocation. Neighboring plants can influence plant fitness directly through competition for resources, and indirectly by altering associated community interactions (associational effects), such as pollination, herbivory, and a suite of belowground interactions. Given the importance of community interactions for plant success, and the known ability for plant neighbors to change these interactions, the goal of this “pandemic project” was to understand how heterospecific plant neighbors alter plant resource allocation, whether this occurred through above‐ or belowground mechanisms, and whether this in turn alters biotic interactions and the relationship between a focal plant and its herbivore and soil community interactions. To do so, we established a common garden experiment, manipulating plant neighbor identity and the extent of interaction among neighbors (aboveground only, vs. above‐ and belowground interactions, using customized pot types), and measured changes to a focal plant and its biotic interactions over two growing seasons. We found evidence of both neighbor effects and pot type, showing that neighbor interactions affect a focal plant through both above‐ and belowground processes, and how the focal plant is affected depends on neighbor identity. Though neighbors did not directly alter herbivory or most soil microbial interactions, they did alter the relationship between belowground microbial communities and a plant response trait (specific leaf area). Plant resource allocation responses were reduced with time, showing the importance of extending experiments beyond a single growing season, and are an important consideration when making predictions about plant responses to changing conditions. This study contributes to a growing body of work showing how community contexts affect the above‐ and belowground interactions of a plant through plant resource allocation strategies.

中文翻译：

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植物邻居通过改变资源分配来差异性地改变重点物种的生物相互作用


植物资源分配策略被认为在很大程度上是不断变化的非生物条件和进化历史的结果。然而，生物相互作用也会影响植物分配资源的方式。因此，植物通过资源分配介导地上和地下生物之间的间接相互作用。邻近植物可以通过争夺资源直接影响植物的适应性，也可以通过改变相关的群落相互作用（关联效应）间接影响植物的适应性，例如授粉、食草和一系列地下相互作用。鉴于群落互动对植物成功的重要性，以及植物邻居改变这些相互作用的已知能力，这个“大流行项目”的目标是了解异种植物邻居如何改变植物资源分配，这是通过地上还是地下机制发生的，以及这是否反过来改变了生物相互作用以及焦点植物与其食草动物和土壤群落相互作用之间的关系。为此，我们建立了一个共同的花园实验，操纵植物邻居的身份和邻居之间的相互作用程度（仅使用地上，与地上和地下的相互作用，使用定制的花盆类型），并测量了两个生长季节中焦点植物的变化及其生物相互作用。我们发现了邻域效应和盆栽类型的证据，表明邻域交互通过地上和地下过程影响焦点植物，而焦点植物的影响方式取决于邻居身份。 尽管邻居没有直接改变食草或大多数土壤微生物相互作用，但它们确实改变了地下微生物群落与植物反应性状（特定叶面积）之间的关系。植物资源分配响应随着时间的推移而减少，显示了将实验扩展到单个生长季节之外的重要性，并且是预测植物对变化条件的反应时的重要考虑因素。这项研究有助于越来越多的工作，展示群落环境如何通过植物资源分配策略影响植物的地上和地下相互作用。