Early seral vegetation communities increase insect abundance and diversity in a semiarid natural gas field during early and late growing season

Abstract

Insects are critical components of terrestrial ecosystems and are often considered ecosystem engineers. Due to the vast amount of ecosystem services they provide, because statistically valid samples can be captured in short durations, and because they respond rapidly to environmental change, insects have been used as indicators of restoration success and ecosystem functionality. In Wyoming (USA), thousands of acres of land surface has been disturbed to extract natural resources. While traditional reclamation practices of these lands focused on site stabilization and weed control, more recent efforts have been made to restore ecosystem services. It has been suggested that a spatial and temporal mosaic of flowering species will benefit insect populations. In this study, we compared early seral reclamation sites (i.e., well pads undergoing interim reclamation) to reference areas at two points within a growing season. We found reference ecosystems were devoid of forb species, while one year old reclaimed sites contained late-season blooming Rocky Mountain beeplant (Cleome serrulata) and three-four year old well pads contained early-season blooming perennial forb species, mainly western yarrow (Achillea millefolium). We compared insect abundance and family richness on 6 well pads with early season perennial forbs and 6 well pads with the late season annual forb, Rocky Mountain beeplant to insect communities on adjacent reference areas. A total of 237 insects were found on early season reclaimed sites compared to 84 on reference sites, while 858 insects were found on late season reclaimed sites compared to 40 on reference sites. Insect abundance and family richness was significantly higher on reclaimed well pads compared to reference areas at both points in the growing season. We also found interesting differences in abundance at family levels.