Pre-development and post-closure landscape dynamics in oil-sands mining : implications for assessment of reclamation and equivalent capability

Site-level evaluation of reclamation performance and residual impacts (i.e., post-reclamation effects) of large mining projects has conventionally used an approach in which landscape conditions (e.g., amounts of certain vegetation types or wildlife habitats) immediately prior to development are characterized and used as a baseline against which to assess post-reclamation conditions. This approach is static, in that it evaluates post-reclamation conditions, usually at a single time in the future, against a “snapshot” of conditions at a single pre-development time. However, many of the characteristics typically evaluated through this approach are both spatially and temporally dynamic, on both the “pre-disturbance” and post-reclamation landscape: • “pre-disturbance” – mining is almost always not the first disturbance of a landscape, which has generally been repeatedly subjected to substantial and recent perturbations such as wildfire, and thus has undergone many pre-mining cycles of disturbance and recovery; • post-reclamation – reclaimed landscapes evolve over time, and their characteristics and utility (to humans and other species) change with this evolution, which may be affected by new future cycles of disturbance and recovery. This conventional assessment conceptual model then is highly dependent on both the specific conditions existing in a project area immediately prior to industrial development, and on the future time selected for post-reclamation assessment. In this paper we argue that the broad application of this conceptual model has resulted in a simplistic understanding of landscape responses to industrial disturbances, and has contributed an arbitrary component to reclamation planning and assessment. We propose that alternative approaches (e.g., use of ecological simulation modelling) in which pre- and post-development landscape dynamics are explicitly acknowledged and accounted for are necessary to gain a more sophisticated and useful understanding of the role of mining and reclamation in the cycle of ecosystem disturbance and recovery. An example of such an approach is presented using a case study from oil-sands mining and reclamation in northeast Alberta, Canada.Non UBCUnreviewedOthe