Recovery of plains rough fescue grasslands on reclaimed well sites

Abstract

Plains rough fescue (Festuca hallii), once dominant in grasslands of the Northern Great Plains, has been reduced to remnants mainly through agricultural and energy sector development. This study assessed the impacts of oil and gas well site disturbances on plains rough fescue grassland to predict successional trends following disturbance. We examined trends in vegetation cover, richness, diversity, and community composition for two construction techniques (topsoil stripping, minimum disturbance), three revegetation methods (agronomic seed mix, native seed mix, natural recovery), and two reclamation scenarios (reclaimed within < 10 yrs; reclaimed within > 10 yrs) relative to adjacent undisturbed prairie (reference sites) over 28 years in 33 grassland sites. Reclamation success was more closely related to methods of construction and revegetation than years since reclamation. Species richness, diversity, both native and non-native species cover, and species composition were similar between undisturbed prairie and areas subject to minimum disturbance and natural recovery. In contrast, undisturbed prairie differed from areas with topsoil stripping and seeding to either agronomic or native species. Plant community composition on minimum disturbance sites with natural recovery was returning to a predisturbed plains rough fescue community within 10 years after reclamation. Impacts of construction method that involved intensive soil handling and seeding with native or non-native seed mixes were disruptive to recovery of fescue grassland. We therefore recommend retaining grassland sod intact through minimum disturbance and utilizing natural recovery as the best option for successful reclamation of native rough fescue grassland after well site disturbance.