Spread rates on fragmented landscapes: the interacting roles of demography, dispersal and habitat availability
Spread rates on fragmented landscapes: the interacting roles of demography, dispersal and habitat availability
复制标题
DOI：
10.1111/ddi.12487
复制
发表时间：
2016-12-01
影响因子：
4.6
通讯作者：
Travis, Justin M. J.
中科院分区：
文献类型：
--
作者：
Barros, Ceres;Palmer, Stephen C. F.;Travis, Justin M. J.
我们仍然缺乏对种群分布、分布和景观特征对物种范围扩张率的相对重要性以及这些因素如何相互作用的全面认识。本文通过研究生境质量、可得性和破碎化等生境特征与物种扩散特征的相互作用对物种RRE的影响，分析了这些影响对被动传播者的影响。此外，我们还评估了在我们了解物种的人口分布、分布和栖息地可用性的情况下，RRE的可预测性。方法利用基于个体的RangeShifter模拟平台，通过不同的平均扩散距离和迁移数量，模拟不同扩散能力物种在不同景观上的范围扩展。景观在生境质量（就承载力和物种增长率而言）和生境可利用性（就适宜生境的比例及其破碎化程度而言）方面各不相同。结果6个主效应对RRE变化的贡献率为55%，在生境破碎化程度较高的景观中，RRE变化速度较快，受生境破碎化程度影响较小。适宜生境数量与物种扩散特征之间的协同效应对范围扩展具有显著的正向影响。然而，值得注意的是，33%的RRE变化不能用任何被测因素或它们之间的相互作用来解释，并且可以被认为是固有的和不可减少的不确定性。基于模拟的方法提供了与保护规划相关的RRE驱动因素的重要见解。例如，我们的结果表明，什么时候分配资源来改善现有的栖息地比创造新的栖息地更好，反之亦然。此外，我们的研究结果强调，RRE通常存在很大的不确定性，这需要在生态管理中加以考虑。
AimWe still lack a comprehensive understanding of the relative importance of demographic, dispersal and landscape characteristics on species' rates of range expansion (RRE) and on how these factors interact. Here, we provide an analysis of these effects for passive dispersers, by investigating how habitat characteristics, such as habitat quality, availability and fragmentation, interplay with species' dispersal characteristics in determining species' RRE. In addition, we assessed the predictability of RRE in cases where we have the knowledge of a species' demography, dispersal and habitat availability.MethodsUsing the newly available individual-based modelling platform, RangeShifter we simulated the range expansion of species with different dispersal abilities, by varying mean dispersal distance and number of emigrants, on various landscapes. Landscapes varied in habitat quality (in terms of carrying capacity and species' growth rates) and in habitat availability (in terms of the proportion of suitable habitat and its degree of fragmentation).ResultsOur results show that 55% of the total variation in RRE was explained by our six main effects, being considerably faster in landscapes with more suitable habitat, but only slightly affected by the degree of habitat fragmentation. Also, synergies between the amount of suitable habitat and species dispersal characteristics had significant positive effects on range expansion. Notably, however, 33% of variation in RRE was not explained by any of the tested factors or interactions between them and can be considered inherent and irreducible uncertainty.Main conclusionsSimulation-based approaches provide important insights into the drivers of RRE that are relevant for conservation planning. For instance, our results indicate when it is likely to be better to allocate resources to improve existing habitat rather than creating new habitat, and vice versa. Additionally, our results emphasize that there will often be substantial uncertainty in the RRE, which needs to be taken into account for ecological management.