Trends in avian use of reclaimed boreal forest habitat in Canada's oil sands

Abstract

Located in the northeastern portion of the Canadian province of Alberta, the Athabasca Oil Sands Region (AOSR) supports large-scale bitumen mining operations. Such development has considerable impacts upon the landscape; however, upland habitat reclamation is underway, providing an opportunity to assess wildlife usage patterns associated with reclaimed habitats relatively early in the reclamation process. Using passerines and woodpeckers as an indicator of wildlife usage of landforms reclaimed to an upland forest type consistent with the surrounding and naturally occurring upland boreal forest, across six oil sands leases in the mineable portion of the oil sands region, we observed that reclaimed areas increased in community similarity to reference mature boreal forest plots over 35 years. Community similarity 35 years post-disturbance between reference and reclaimed sites varied from 20-65%, with an overall average of ~43%. Such low and variable similarity values were expected, as 35 years is early in the recovery process from the perspective of forest succession. Younger plots disturbed by activities other than mining, such as fire and logging (9 to 10 years post-disturbance), were associated with bird communities that were more similar to older reclaimed plots (those >30 years post-reclamation) suggesting that areas not disturbed by mining are progressing along different recovery trajectories than areas disturbed by mining. Given the time it takes for vegetation communities in the boreal to mature, continued research is required to assess the longer-term functionality of reclaimed habitats, the end point of succession in all disturbed habitat types, as well as to determine what level of community similarity between reference and reclaimed plots is satisfactory from an ecological and regulatory perspective. Despite the observed differences between reclaimed habitats and mature forests, reclamation efforts in the mineable portion of the AOSR appear to be contributing to the development of upland boreal forest habitats that resemble those of the surrounding and naturally occurring boreal forest.