Reigada Carolina, Schreiber Sebastian J, Altermatt Florian, Holyoak Marcel
Department of Entomology and Acarology, Escola Superior de Agricultura Luiz de Queiroz (ESALQ), University of São Paulo, Piracicaba, Brazil.
Am Nat. 2015 Feb;185(2):183-95. doi: 10.1086/679502. Epub 2015 Jan 9.
A challenge for conservation management is to understand how population and habitat dynamics interact to affect species persistence. In real landscapes, timing and duration of disturbances can vary, and species' responses to habitat changes will depend on how timing of dispersal and reproduction events relate to the landscape temporal structure. For instance, increasing disturbance frequency may promote extinction of species that are unable to appropriately time their reproduction in an ever-changing habitat and favor species that are able to track habitat changes. We developed a mathematical model to compare the effects of pulsed dispersal, initiated by shifts in habitat quality, with temporally continuous dispersal. We tested the effects of habitat (and population) turnover rates on metapopulation establishment, persistence, and long-term patch occupancy. Pulsed dispersal reduced patch occupancy and metapopulation longevity when habitat patches are relatively permanent. In such cases, demographic extinction was the primary form of local extinction. Conversely, when habitat patches are short-lived and new ones are frequently formed, pulsed dispersal promoted rapid colonization, increased occupancy, and prolonged metapopulation persistence. Our results show that species responsiveness to habitat disturbance is critical to metapopulation persistence, having profound implications for the species likely to persist in landscapes with altered disturbance regimes.
保护管理面临的一个挑战是了解种群动态和栖息地动态如何相互作用以影响物种的持续生存。在现实景观中，干扰的时间和持续时间可能各不相同，物种对栖息地变化的反应将取决于扩散和繁殖事件的时间与景观时间结构的关系。例如，干扰频率增加可能会促使那些无法在不断变化的栖息地中适时繁殖的物种灭绝，并有利于那些能够追踪栖息地变化的物种。我们开发了一个数学模型，以比较由栖息地质量变化引发的脉冲式扩散与时间上连续扩散的影响。我们测试了栖息地（和种群）周转率对集合种群建立、持续生存和长期斑块占据情况的影响。当栖息地斑块相对持久时，脉冲式扩散会降低斑块占据率和集合种群寿命。在这种情况下，种群统计学意义上的灭绝是局部灭绝的主要形式。相反，当栖息地斑块寿命短暂且新斑块频繁形成时，脉冲式扩散会促进快速定殖、增加占据率并延长集合种群的持续生存时间。我们的结果表明，物种对栖息地干扰的反应能力对于集合种群的持续生存至关重要，这对可能在干扰格局改变的景观中持续生存的物种具有深远影响。
