Oilfield reclamation recovers productivity but not composition of arthropod herbivores and predators

Authors: Sylvain, Zachary; Espeland, Erin; Rand, Tatyana; West, Natalie; Branson, David - Dave

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2019
Publication Date: 2/20/2019
Citation: Sylvain, Z.A., Espeland, E.K., Rand, T.A., West, N.M., Branson, D.H. 2019. Oilfield reclamation recovers productivity but not composition of arthropod herbivores and predators. Environmental Entomology. 48(2):299-308. https://doi.org/10.1093/ee/nvz012.
DOI: https://doi.org/10.1093/ee/nvz012

Interpretive Summary: Insects and spiders are important parts of rangeland ecosystems but are less well studied and understood than are plants and wildlife. This is especially true when examining how ecosystems recover following reclamation after energy development. Energy development is an important driver of land-use change in the northern Great Plains, but reclamation efforts typically focus only on plants under the assumption that other associated groups will recover on their own once the plant community is reestablished. We sampled spiders (predators) and Orthoptera (i.e., herbivores including grasshoppers, crickets and katydids) on reclaimed well sites (ranging from 3 to 33 years since reclamation) and on intact, native prairie at two distances (50 m and 150 m) from reclaim edges in western North Dakota rangelands. We found that predators and herbivores showed different degrees of recovery after energy development and reclamation. The abundance and biomass of both groups recovered on reclaims to similar levels found on native prairie; however while spider communities on reclaims closely resembled those of native prairie, Orthopteran communities on reclaims were clearly different from those on native prairie, even after 30 years of recovery time. Notably, the red-legged grasshopper (Melanoplus femurrubrum, a recognized grasshopper pest of crops), was more prevalent on reclaims than surrounding rangelands. Our results emphasize the importance of examining ecosystem recovery for organisms at many levels of the food web and suggest that energy development may have irreversible impacts to rangeland ecosystems.

Technical Abstract: Arthropods are a key, under-studied component of grassland ecosystems. Though arthropod community structure is often strongly influenced by plant community structure, plants and arthropods may respond differently to disturbance. Studying plant responses alone may therefore not fully capture altered ecosystem dynamics; thus multi-trophic approaches are critical to fully understand ecosystem responses to disturbance. Energy development is a large-scale driver of disturbance in northern Great Plains rangelands, and recovery of arthropod communities following reclamation is not well understood. We sampled Orthoptera and spiders on reclaimed well sites (“reclaims”) ranging from 3 to 33 years since reclamation, and two distances (50 and 150 m) from reclaim edges on native prairie at 14 sites in western North Dakota, USA, in 2016. Overall Orthopteran and spider abundances on reclaims and native prairie did not differ; however Orthopteran community structure was distinct on reclaims compared with native prairie, including increased abundances of Melanoplus femurrubrum (a noted crop pest) on reclaims. In contrast, there were no differences in spider community composition between reclaims and native prairie, with only one group (Salticidae) showing decreased abundances on reclaims. We present one of the first studies to investigate the impacts of energy development and reclamation on arthropod communities. While reclamation efforts successfully recovered the abundance and biomass of arthropod herbivores and predators, Orthopteran (but not spider) community structure on reclaims has not recovered to match that of intact prairie even 30 years after reclamation. These findings suggest that energy development may have irreversible impacts to rangeland arthropod communities.