Abstract:
Invasions are commonly found to benefit from disturbance events. However, the importance of the relative timing of the invasion and disturbance for invader success and impact on community composition remains uncertain. Here, we experimentally test this by invading a five-species bacterial community on eight separate occasions-four before a disturbance and four after. Invader success and impact on community composition was greatest when the invasion immediately followed the disturbance. However, the subsequent invasions had negligible success or impact. Pre-disturbance, invader success and impact was greatest when the invader was added just before the disturbance. Importantly, however, the first three pre-disturbance invasion events had significantly greater success than the last three post-disturbance invasions. Moreover, these findings were consistent across a range of propagule pressures. Overall, we demonstrate that timing is highly important for both the success and impact on community composition of an invader, with both being lower as time since disturbance progresses.
摘要:
入侵通常会从干扰事件中受益。然而,入侵和干扰的相对时间对入侵者成功的重要性以及对社区组成的影响仍不确定。这里,我们通过在八次不同的情况下入侵五种细菌群落来进行实验测试,其中四次在干扰之前,四次在干扰之后。当入侵紧随干扰之后,入侵者的成功和对社区组成的影响最大。然而,随后的入侵取得了微不足道的成功或影响。预干扰,入侵者的成功和影响是最大的,当入侵者被添加之前的干扰。重要的是,然而,前三次扰动前入侵事件的成功率明显高于后三次扰动后入侵.此外,这些发现在一系列繁殖压力中是一致的.总的来说,我们证明了时机对于入侵者的成功和对社区组成的影响都非常重要,随着干扰的进行,两者都会随着时间的推移而降低。