Muhly Tyler, Serrouya Robert, Neilson Eric, Li Haitao, Boutin Stan
Alberta Biodiversity Monitoring Institute, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada; Stantec, Environmental Services, Sidney, British Columbia, Canada.
Alberta Biodiversity Monitoring Institute, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
PLoS One. 2015 Sep 8;10(9):e0136933. doi: 10.1371/journal.pone.0136933. eCollection 2015.
In-situ oil sands development (ISD) involves a network of facilities, wells, roads and pipelines to extract and transport subsurface bitumen. This technology is rapidly expanding and there is uncertainty whether ISDs restrict animal movement, leading to increased extinction probabilities for some wide-ranging species. Here we test for effects of simulated future (i.e., 50 years from now) and current ISDs on simulated movements of woodland caribou (Rangifer tarandus), a threatened species across North America. In simulations of future scenarios, we varied the spacing and permeability of ISDs and the presence/absence of protected areas. Permeability was measured as the number of times simulated caribou crossed ISDs with different levels of modelled permeability. We estimated the effects of these factors on caribou step length and annual home range size, key metrics of small and large spatiotemporal scales of movement, respectively. Current caribou crossings of above-ground pipeline features of ISDs were measured using camera traps and compared to expected caribou crossing rates based on present-day caribou movement simulations. Current crossing rates were evaluated within the context of predicted future crossing success rates necessary to maintain caribou step lengths and home ranges. With few exceptions, permeability across ISDs was the main factor affecting caribou movement, more so than spacing between developments or the presence of protected areas. However, minimal permeability (crossing rates of c. 15% to 60%, relative to an undisturbed site was needed to maintain existing home range size and step lengths. The effect of permeability on home range size and step length was non-linear, suggesting that small increases in permeability would provide a disproportionately greater benefit to caribou movement. Our predictions demonstrate that maintaining permeability across ISDs is more important than spacing between leases or including protected areas, and thus provides clear direction for mitigation efforts for features that will exist on the landscape for decades to come.
原地油砂开发（ISD）涉及一系列设施、油井、道路和管道，用于开采和运输地下沥青。这项技术正在迅速扩张，而ISD是否会限制动物迁移，从而导致一些分布广泛的物种灭绝概率增加，目前尚不确定。在此，我们测试了模拟的未来（即从现在起50年后）和当前的ISD对北美受威胁物种林地驯鹿（Rangifer tarandus）模拟迁移的影响。在未来情景模拟中，我们改变了ISD的间距和渗透率以及保护区的有无。渗透率通过模拟驯鹿穿越具有不同模拟渗透率水平的ISD的次数来衡量。我们估计了这些因素对驯鹿步长和年度家域面积的影响，这两个指标分别是小尺度和大尺度时空迁移的关键指标。利用相机陷阱测量了当前驯鹿穿越ISD地面管道设施的情况，并与基于当前驯鹿迁移模拟得出的预期穿越率进行了比较。在维持驯鹿步长和家域所需的预测未来穿越成功率的背景下，对当前穿越率进行了评估。除了少数例外情况，ISD的渗透率是影响驯鹿迁移的主要因素，比开发区之间的间距或保护区的存在影响更大。然而，需要最低渗透率（相对于未受干扰的地点，穿越率约为15%至60%）来维持现有的家域面积和步长。渗透率对家域面积和步长的影响是非线性的，这表明渗透率的小幅增加将为驯鹿迁移带来不成比例的更大益处。我们的预测表明，维持ISD的渗透率比租约之间的间距或纳入保护区更为重要，因此为未来几十年景观中将会存在的特征的缓解措施提供了明确的方向。
