Population‐level consequences of risky dispersal
Population‐level consequences of risky dispersal
复制标题
危险扩散对人口造成的后果
作者：
Allison K. Shaw;M. Jalasvuori;H. Kokko
在种群之间实现足够的连通性对于可持续性至关重要，但扩散的代价可能会对个体特征或行为产生不利影响，如果存在的话，这些特征或行为将改善连通性。现有的扩散模型往往忽视了个体面临的众多风险：虽然许多模型评估了死亡成本的影响，但也存在找不到新栖息地的风险，特别是在整个宜居区仍然很小和分散的情况下。很少有已知的规则来决定个体的进化是更多还是更少地分散，而不是对种群连通性和持久性来说是理想的。在这里，我们的目标是填补这一空白，同时也注意到进化可能不仅会产生次优的扩散行为：它还会影响个体在扩散中的异质性。直觉上，我们可能会认为异质性会改善连通性，因为一些人会旅行很远。然而，我们表明，只有在平均扩散距离相当短的情况下，这种情况才是正确的；异质性也会导致连通性降低，因为它可以减少最有利可图的(最安全的)中间扩散距离的比例。总体而言，我们的结果表明，通常与保护问题相关的条件(出生率低的物种栖息的小而零散的栖息地)也是最有可能导致次优扩散特征的条件。这引发了在迫切需要保护的情况下协助疏散的问题。
Achieving sufficient connectivity between populations is essential for persistence, but costs of dispersal may select against individual traits or behaviours that, if present, would improve connectivity. Existing dispersal models tend to ignore the multitude of risks to individuals: while many assess the effect of mortality costs, there is also a risk of failing to find new habitat, especially when the entire inhabitable area remains both small and fragmented. There are few known rules governing whether individuals evolve to disperse more, or less, than what is ideal for population connectivity and persistence. Here we aim to fill this gap, while also noting that evolution might not only produce suboptimal dispersal behaviour: it also influences individual heterogeneity in dispersal. Intuitively, we might expect heterogeneity to improve connectivity, as some individuals will travel far. However, we show that this is only true if dispersal distances on average are quite short; heterogeneity can also lead to reduced connectivity because it can reduce the proportion of the most profitable (‘safest’) intermediate dispersal distances. In general, our results show that conditions typically associated with conservation concerns (small and fragmented habitats inhabited by a species with a low birth rate) are also ones that are most likely to lead to suboptimal dispersal traits. This prompts the question of assisted dispersal in cases of urgent conservation concern.
影响因子：
2
作者：
FRANK, SA
通讯作者：
FRANK, SA