Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4389798 | Ecological Engineering | 2013 | 10 Pages |
Oil sands mining creates vast areas of disturbed land with contaminated sediment and sub-saline water that require reclamation. Thus far reclamation of wetlands on oil sand leases has been sporadic, although some marshes and shallow water wetlands developing on the leases have begun to exhibit viable vegetation communities. To identify the communities found on oil sands leases that demonstrate ecological performance similar to that of natural wetlands, and to provide guidance on specific revegetation practices, we compared the vegetation communities of 25 natural fresh to sub-saline marshes, which represent the most realistic outcome of the reclaimed wetlands, and 20 oil sands reclaimed marshes. We found that wetlands did not have consistent vegetation communities on the basis of their construction history, and that exposure to oil sands process-affected water does not determine the vegetation community that will develop in reclaimed oil sands wetlands. We identified three wet meadow vegetation communities among our study wetlands using the statistical technique of hierarchical cluster analysis: sedge-dominated natural reference, reclaimed sedge, and disturbed/saline. Notably, the reclaimed sedge communities in the oil sands sites were different from sedge communities in natural marshes; Carex aquatilis Wahlenb. dominates reclaimed sites whereas Carex atherodes Spreng. dominates natural sites. The majority of vegetation communities that develop in reclaimed wetlands produce less aboveground biomass than natural wetlands, despite having similar species richness and percent cover. In general, oil sands reclaimed wetlands have lower levels of sediment nutrients and lower sediment water content than natural wetlands, and these deficiencies may be limiting vegetation community biomass production compared to natural wetlands. The presence of a Carex species-dominated vegetation community at some reclaimed sites shows promise for future reclamation success, if revegetation targets the establishment of this community.
► We identified three wet meadow vegetation communities among study wetlands. ► Oil sands sedge communities were different from sedge communities in natural marshes. ► Reclaimed wetland communities produced less biomass than natural communities. ► Carex species-dominated vegetation communities show promise for future reclamation.