Plants face trade‐offs between allocating resources to growth, while also defending against herbivores or pathogens. Species differences along defense trade‐off axes may promote coexistence and maintain diversity. However, few studies of plant communities have simultaneously compared defense trade‐offs against an array of herbivores and pathogens for which defense investment may differ, and even fewer have been conducted in the complex natural communities in which these interactions unfold. We tested predictions about the role of defense trade‐offs with competition and growth in diversity maintenance by tracking plant species abundance in a field experiment that removed individual consumer groups (mammals, arthropods, fungi) and added nutrients. Consistent with a growth–defense trade‐off, plant species that increased in mass in response to nutrient addition also increased when consumers were removed. This growth–defense trade‐off occurred for all consumer groups studied. Nutrient addition reduced plant species richness, which is consistent with trade‐off theory. Removing foliar fungi increased plant diversity via increased species evenness, whereas removal of other consumer groups had little effect on diversity, counter to expectations. Thus, while growth–defense trade‐offs are general across consumer groups, this trade‐off observed in wild plant communities does not necessarily support plant diversity maintenance.

中文翻译：

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植物生长与防御的权衡在与真菌、昆虫和哺乳动物消费者的相互作用中普遍存在

植物面临着分配资源以促进生长和防御食草动物或病原体之间的权衡。沿着防御权衡轴的物种差异可能会促进共存并保持多样性。然而，很少有植物群落的研究同时比较了防御投资可能不同的一系列食草动物和病原体的防御权衡，而在这些相​​互作用展开的复杂自然群落中进行的研究就更少了。我们通过在田间实验中跟踪植物物种丰度来测试关于防御权衡与竞争和增长在多样性维持中的作用的预测，该实验去除了单个消费群体（哺乳动物、节肢动物、真菌）并添加了营养物质。与生长与防御的权衡一致，当消费者被移除时，因营养添加而增加质量的植物种类也会增加。这种增长与防御的权衡发生在所有研究的消费者群体中。养分添加降低了植物物种丰富度，这与权衡理论一致。去除叶面真菌通过增加物种均匀度来增加植物多样性，而去除其他消费群体对多样性几乎没有影响，这与预期相反。因此，虽然生长与防御之间的权衡在消费者群体中普遍存在，但在野生植物群落中观察到的这种权衡并不一定支持植物多样性的维持。