As oil and gas development has grown on arid lands, so have the number of abandoned well pads. Without support, these heavily degraded pads may take up to a century to recover to previous cover values. Research is needed to understand barriers to native shrub establishment and/or growth and how to overcome them during restoration. To that end, we compared the physiological status of Wyoming big sagebrush, Artemisia tridentata var. wyomingensis, and soil compaction between abandoned pads and adjacent reference sites. The study was conducted in the sagebrush community of the Northern Colorado Plateau in Utah, in the summer of 2018. We measured rates of photosynthesis, stomatal conductance, internal CO2 concentrations, transpiration, predawn and midday water potentials on Artemisia tridentata var. wyomingensis or Wyoming Big Sagebrush, in both disturbed pads and adjacent undisturbed reference sites. We also measured soil compaction levels on and off pads to determine whether compaction is among the potential barriers to shrub establishment.
Results/Conclusions
Sagebrush on pads had higher rates of photosynthesis and lower predawn potentials than plants off the pad, indicating greater water availability on the pads, probably because of very low plant densities. However, soil compaction was greater on pads than reference sites. This suggests that soil compaction may inhibit establishment rates but that successful establishers may benefit from reduced competition for water in this arid environment. These initial results will guide our next experiment, in which we will test different methods of soil preparation to enhance the survivorship of seedlings and transplants.