School of Geography, Planning and Environmental Management, The University of Queensland, Brisbane, Queensland, Australia; ARC Centre of Excellence for Environmental Decisions, The University of Queensland, Brisbane, Queensland, Australia; NERP Environmental Decisions Hub, The University of Queensland, Brisbane, Queensland, Australia.
Office of Environment and Heritage New South Wales, Hurstville, New South Wales, Australia; School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.
PLoS One. 2014 Mar 19;9(3):e91093. doi: 10.1371/journal.pone.0091093. eCollection 2014.
Roads and vehicular traffic are among the most pervasive of threats to biodiversity because they fragmenting habitat, increasing mortality and opening up new areas for the exploitation of natural resources. However, the number of vehicles on roads is increasing rapidly and this is likely to continue into the future, putting increased pressure on wildlife populations. Consequently, a major challenge is the planning of road networks to accommodate increased numbers of vehicles, while minimising impacts on wildlife. Nonetheless, we currently have few principles for guiding decisions on road network planning to reduce impacts on wildlife in real landscapes. We addressed this issue by developing an approach for quantifying the impact on wildlife mortality of two alternative mechanisms for accommodating growth in vehicle numbers: (1) increasing the number of roads, and (2) increasing traffic volumes on existing roads. We applied this approach to a koala (Phascolarctos cinereus) population in eastern Australia and quantified the relative impact of each strategy on mortality. We show that, in most cases, accommodating growth in traffic through increases in volumes on existing roads has a lower impact than building new roads. An exception is where the existing road network has very low road density, but very high traffic volumes on each road. These findings have important implications for how we design road networks to reduce their impacts on biodiversity.
道路和车辆交通是对生物多样性最普遍的威胁之一，因为它们会破坏栖息地、增加死亡率，并为自然资源的开发开辟新的区域。然而，道路上的车辆数量正在迅速增加，这种情况在未来可能会继续下去，这将给野生动物种群带来更大的压力。因此，一个主要的挑战是规划道路网络以容纳更多的车辆，同时尽量减少对野生动物的影响。尽管如此，我们目前几乎没有指导道路网络规划决策以减少对真实景观中野生动物影响的原则。我们通过开发一种方法来解决这个问题，该方法用于量化两种替代机制对容纳车辆数量增长的影响，这两种机制是：（1）增加道路数量，（2）增加现有道路上的交通量。我们将这种方法应用于澳大利亚东部的考拉（Phascolarctos cinereus）种群，并量化了每种策略对死亡率的相对影响。我们表明，在大多数情况下，通过增加现有道路上的交通量来容纳交通增长的影响比建造新道路要小。一个例外是现有道路网络的道路密度非常低，但每条道路上的交通量非常高。这些发现对我们如何设计道路网络以减少对生物多样性的影响具有重要意义。
