Evaluating the Revegetation Success of Foothills Fescue Grassland

Jay Woosaree, Alberta Innovates

Plains Rough fescue grassland (Festuca hallii [vasey] Piper) found almost entirely within Canada occur within the Aspen Parkland natural region extending from central Alberta, southeast through Saskatchewan and into Manitoba. Main concern is that fescue grassland now covers approximately less than 5% of the grassland they were once found. Public land managers and land stewardship organizations are concerned about the loss of fescue grassland due to resource development and with the difficulty of restoring the disturbed areas (Bradley, 2003) to its original state. Ability to revegetate and maintain the remaining fescue grassland is essential to preserve this ecosystem.

Past revegetation of disturbed land in Alberta was accomplished using mainly commercial non-native forage species. Many of these forage species are highly competitive and their use in re-vegetation projects has excluded native prairie species from returning to reclaimed sites. In some cases, these non-native species, such as smooth brome grass (Bromus inermis Leyss. spp. inermis), alfalfa (Medicago sativa L.), and crested wheatgrass (Agropyron cristatum L. Gaertn), Kentucky bluegrass (Poa pratensis L.), and Canada bluegrass (Poa compressa L.), have invaded surrounding native prairies from reclaimed areas (Adam et al., 2003). These species are now considered invasive plants of natural habitats (White et al. 1995). The use of these forage species in reclamation has resulted in landscape fragmentation, reduced species diversity and a decrease in ecosystem function across the landscape.

Alberta starts advocating the use of native species in 1995 (Alberta Environmental Protection, 1995), but a low availability of native species limits their use in reclamation projects. Following 1995, cultivars of wheatgrasses became common in seed mixes because they were available in large quantities, are relatively cheap and provide a rapid establishment. Although these wheatgrasses are regarded as better than a non-native forage seed mix, concerns were still raised (Gill Environmental Consulting, 1996) about the species diversity of reclaimed areas and their compatibility with the surrounding native vegetation. The problem is further confounded by the 1995 reclamation criterion stipulating rapid establishment of 80% plant cover (Alberta Environment, 2007). Reclamation industries thereby use a high seeding rate in order to obtain the desired plant cover. At the time reclamation criteria were established, our understanding of grassland ecosystem recovery processes was lacking. A five year study was undertaken to determine what constitutes successful reclamation on abandoned well sites in the native fescue prairie. The goal of this project was to develop a methodology for re-vegetating well site disturbances on native fescue prairie that would jump start natural successional processes and return the site to sound ecological structure and function similar to that of the surrounding undisturbed native prairie.

Policy Issue
The effectiveness of industrial footprint reclamation. One of the primary challenges facing the oil and gas industry is effectively returning a range of landscapes to pre-disturbance conditions

Knowledge Gap
Wildlife (including mammal, amphibian and bird) use of reclaimed habitats compared to pre-disturbed habitats

2011 Report