Plant community development on petroleum drill sites in northwestern Wyoming

Abstract

Plant community and soil development were investigated on oil/gas drilling sites occupying both sagebrush and coniferous forest vegetation types in northwestern Wyoming. Sites ranged from 3 to 33 years in age since abandonment. Some sites were seeded at abandonment, while others revegetated naturally. Vegetation and soils were sampled and compared on disturbed and adjacent undisturbed sites. Both soils and vegetation were altered by drilling activities. Disturbed soils generally had higher bulk density and pH and lower organic matter content than undisturbed soils. All disturbed sites were vegetationally dissimilar to adjacent native sites. However, sagebrush disturbances were progressing toward undisturbed conditions more rapidly than coniferous forest disturbances. Seeding accelerated vegetation development, although at different rates between sagebrush and coniferous forest disturbances. Seeding and establishment of introduced grass species on disturbed sites did not prevent natural recolonization of native species.