The spatial patterns of anthropogenic disturbance in the western Canadian boreal forest following oil and gas development

Abstract

Resource development can have significant consequences for the distribution of vegetation cover and for species persistence. Modelling changes to anthropogenic disturbance regimes over time can provide profound insights into the mechanisms that drive land cover change. We analyzed the spatial patterns of anthropogenic disturbance before and after a period of significant oil and gas extraction in two boreal forest subregions in Alberta, Canada. A spatially explicit model was used to map levels of anthropogenic forest crown mortality across 700 000 ha of managed forest over a 60-year period. The anthropogenic disturbance regime varied both spatially and temporally and was outside the historical range of variability characterized by regional fire regimes. Levels of live forest crown within anthropogenic disturbances declined and edge density increased following oil and gas development, whereas patch size varied regionally. In some places, anthropogenic disturbance generated profoundly novel landscapes with spatial patterns that had no historical analogue in the boreal system. The results illustrate that a shift in one sector of the economy can have dramatic outcomes on landscape structure. The results also suggest that any efforts to better align cumulative anthropogenic disturbance patterns with the historic baseline will almost certainly require a concerted and collaborative effort from all of the major stakeholders.Résumé : L'exploitation des ressources peut avoir d'importantes conséquences sur la répartition du couvert végétal et la persistance des espèces. La modélisation des changements temporels dus aux régimes de perturbation anthropique peut déboucher sur une meilleure connaissance des mécanismes qui déterminent les modifications du couvert végétal. Nous avons analysé la configuration spatiale des perturbations anthropiques avant et après une période durant laquelle une quantité importante de pétrole et de gaz a été extraite dans deux forêts boréales en Alberta, au Canada. Un modèle spatialement explicite a été utilisé pour cartographier le niveau de mortalité d'origine anthropique dans le couvert forestier sur un territoire de forêt aménagée de 700 000 ha pendant une période de 60 ans. Le régime de perturbation anthropique a varié dans le temps et l'espace et excédait les limites historiques de variabilité caractérisées par des régimes de feu régionaux. Les niveaux de couvert forestier vivant dans les zones de perturbation anthropique ont diminué et la densité de lisière a augmenté à la suite de l'exploitation du pétrole et du gaz tandis que la dimension des parcelles de forêt variait selon la région. À certains endroits, les perturbations anthropiques ont engendré des paysages totalement nouveaux dont la configuration spatiale n'avait aucun équivalent dans l'histoire du système boréal. Les résultats illustrent le fait qu'un changement dans un secteur de l'économie peut avoir des effets dramatiques sur la structure du paysage. Les résultats indiquent aussi que toute tentative visant faire en sorte que la c...

The importance of considering multiple interacting species for conservation of species at risk

“…Compounding this mature forest loss is the pervasive network of linear features resulting from energy exploration and extraction, which represents a smaller loss in areal extent but plays a disproportionally large role in loss of forest ecosystem function (Pickell et al. ). Nonetheless, predation is the proximate cause of caribou declines, and anthropogenic features bolster alternative prey populations (Toews et al.…”

“…We estimated density to characterize potential predation risk from 3 carnivore species–wolf, black bear, and coyote–on caribou, moose, and white‐tailed deer in a region with high anthropogenic disturbance, Alberta's Oil Sands Region (Pickell et al. ), during the caribou calving season when vulnerability is greatest (Wittmer et al. ).…”

“…Landscape change is considered the ultimate cause of caribou decline; Canada's boreal forest is second only to tropical forests in terms of annual loss of tree cover (Hansen et al 2013). Compounding this mature forest loss is the pervasive network of linear features resulting from energy exploration and extraction, which represents a smaller loss in areal extent but plays a disproportionally large role in loss of forest ecosystem function (Pickell et al 2015). Nonetheless, predation is the proximate cause of caribou declines, and anthro-pogenic features bolster alternative prey populations (Toews et al 2017) and expedite travel by wolves (Canis lupus) (Dickie et al 2017).…”

“…Our motivation was to illustrate how the density of multiple interacting species can be estimated from a camera trap survey, as a basis for more comprehensive and effective conservation decisions. We estimated density to characterize potential predation risk from 3 carnivore species-wolf, black bear, and coyote-on caribou, moose, and white-tailed deer in a region with high anthropogenic disturbance, Alberta's Oil Sands Region (Pickell et al 2015), during the caribou calving season when vulnerability is greatest (Wittmer et al 2005). Published research on the potential impact of predator densities on caribou populations is limited, but given that bears and coyotes are known caribou predators, it is logical to hypothesize that higher densities of predators will lead to greater caribou predation and ultimately further caribou declines.…”

Boreal predator co‐occurrences reveal shared use of seismic lines in a working landscape

“…The Canadian boreal forest is one biome experiencing dramatic landscape change due to natural resource extraction, which is creating a heterogeneous “working” landscape shared between industry and wildlife (Pickell, Andison, Coops, Gergel, & Marshall, ). Logging alone has an area footprint of approximately 15 million hectares, while energy development has created over half a million kilometers of linear features across the region (Pasher, Seed, & Duffe, ).…”