Granivory from native rodents and competition from an exotic invader strongly and equally limit the establishment of native grasses
Granivory from native rodents and competition from an exotic invader strongly and equally limit the establishment of native grasses
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来自本地啮齿动物的谷物和来自外来入侵者的竞争强烈且同样地限制了本地草的建立
作者：
Jacob E. Lucero;R. Callaway
种子捕食和资源竞争是影响植物群落组装的基本生物过滤器，但实证研究很少评估它们相对于彼此的重要性。在这里，我们利用啮齿动物的围堵和实验性种子添加来比较啮齿动物的食粮和资源竞争如何影响美国大盆地沙漠中一种外来入侵者（无芒雀麦）和两种本土束草（Pseudoroegneria spicata 和 Elymus elymoides）的净建立。啮齿类食谷动物限制了两种本土草本植物的建立，但对白芒草没有显着影响。来自白荠菜的竞争限制了两种本土草本植物的建立，但两种本土草本植物都没有对白荠菜产生显着的竞争效应。有趣的是，我们发现啮齿类食谷类动物和 B. tectorum 的竞争在相同程度上限制了本地草本植物的建立，这表明这些生物相互作用可能对 P. spicata 和 E. elymoides 的本地建立造成同样重要的障碍。通过在同时协调的实验中评估多种生物相互作用的强度，我们可以了解它们对群落水平模式的相对贡献。
Seed predation and resource competition are fundamental biotic filters that affect the assembly of plant communities, yet empirical studies rarely assess their importance relative to one another. Here, we used rodent exclosures and experimental seed additions to compare how rodent granivory and resource competition affected the net establishment of an exotic invader (Bromus tectorum) and two native bunchgrasses (Pseudoroegneria spicata and Elymus elymoides) in the Great Basin Desert, USA. Rodent granivory limited the establishment of both native grasses, but had no significant effect on B. tectorum. Competition from B. tectorum limited the establishment of both native grasses, but neither native grass imposed a significant competitive effect on B. tectorum. Interestingly, we found that rodent granivory and B. tectorum competition limited the establishment of native grasses to the same extent, suggesting that these biotic interactions may impose equally important barriers to the local establishment of P. spicata and E. elymoides. By evaluating the strength of multiple biotic interactions in simultaneous, coordinated experiments, we can understand their relative contributions to community-level patterns.