Insect abundance and richness response to ecological reclamation on well pads 5-12 years into succession in a semi-arid natural gas field

Abstract

Natural gas extraction is a critical driver of the economy in western North America. Ecological reclamation is important to ensure surface disturbance impacts associated with natural gas development are not permanent and to assist native biota. Previous studies in semi-arid natural gas fields within Sublette County, Wyoming, USA have shown insects respond favorably to 1-3-year-old well pads undergoing reclamation compared to older successional, reference vegetation communities dominated by Wyoming big sagebrush (Artemisia tridenta spp. Wyomingensis). Here we examined well pads which were initially seeded between 5, 8, 10, 11, and 12 prior to our study. We used a free, image-based software called SamplePoint to quantify vegetation on these well pads and adjacent reference areas from high-resolution cell phone camera pictures. Insects were collected with a sweep net and identified to the family and morphospecies level. Statistical analyses were conducted to compare both vegetation and insect communities between reclamation sites and their paired reference area. We found little statistical difference between vegetation communities across our study, but found significantly more insect abundance in 3 of 5 years and significantly higher family and species richness in 4 of 5 years. Our results suggest reclamation of natural gas well pads within an old successional stand of sagebrush continues to support higher levels of insect biodiversity and abundance for at least 12 years. As insects are the most diverse group of animals on Earth and because they provide a wide array of ecosystem services, our findings suggest ecological reclamation plays an important role in returning biodiversity and ecosystem functionality to a semi-arid and old successional sagebrush-steppe ecosystem.