Expansion of pinyon pine and juniper woodlands into shrublands and grasslands has altered ecosystem function and wildlife habitat across large portions of the interior western U.S. In December 2020, the Bureau of Land Management established the Pinyon-Juniper Management Categorical Exclusion (PJCX) to expedite the regulatory process for pinyon-juniper removal projects on public lands, largely intended to benefit mule deer and sage-grouse habitats. Discontinued by BLM in November 2022, the PJCX permitted removal of trees by either manual cutting, mechanical cutting, or mastication. USGS and University of Idaho researchers conducted a literature review to better understand the likely responses of plant communities, soils, and woodland and sagebrush wildlife communities to different pinyon-juniper removal treatment types. A key finding is that although pinyon-juniper removal may have some benefits to wildlife and native plants, risks from invasive grasses remains a primary concern for nearly all tree removal strategies. The authors identified a lack of research on factors like climate change and livestock grazing and noted that monitoring is needed over longer durations and larger areas to make strong conclusions.   

Shinneman, D.J., McIlroy, S.K., Poessel, S.A., Johnson, T.N., Downing, R.L., Young, A.C., and Katzner, T.E., 2023, Ecological effects of pinyon-juniper removal in the western United States- a synthesis of scientific research, January 2014 - March 2021: U.S. Geological Survey Open-File Report 2023-1041, 56 p., https://doi.org/10.3133/ofr20231041.