Surface-active arthropod community response to juniper removal and its implications for avian conservation in sagebrush ecosystems

Abstract

Terrestrial arthropods are a critical component of sagebrush ecosystems and serve as a key food source for higher trophic levels, including many avian species of conservation concern. The North American sagebrush (Artemisia sp.) biome is in peril, threatened in part by the phenomenon of juniper encroachment. Removal of encroached juniper (Juniperus sp.) has been used by land managers as a widespread restoration technique in sagebrush ecosystems, however, the impact of this restoration action on the arthropod community has not been thoroughly examined. In 2020 and 2021, we studied surface-active arthropod response to juniper treatment in the sagebrush of northern Nevada and northeastern California. Juniper treatments completed between 2008 and 2020 were sampled to assess the impact of this restoration action on the arthropod community over time. Surface-active arthropods were more than twice as abundant in treated sites as untreated sites, however, arthropod taxa diversity was lower in treated sites than untreated sites, despite significantly higher taxa richness in treated sites. Our results suggest that juniper treatments that increase arthropod abundance or diversity may benefit insectivorous sagebrush wildlife by increasing food availability, including for species of conservation concern such as the greater sage-grouse (Centrocercus urophasianus).