By Published On: August 14, 2023

New Report Compiles Knowledge on Climate Resilience of Pinyon-Juniper Woodlands

This article was originally published in the Bureau of Land Management’s internal newsletter, the BLM Daily, on August 14, 2023.

Pinyon-juniper woodlands are incredibly complex and fascinating places that have recently been receiving a lot of attention. A highly diverse ecosystem of 100 million acres, “PJ” is often used to describe such diverse habitat types as the ancient western juniper of eastern Oregon, the Utah juniper and two-needle pinyon stands of the Colorado Plateau, and the young pinyons and junipers expanding into imperiled sagebrush steppe. It’s as if this ecosystem is being displayed in one color on a map of the West, when really it should be depicted in a suite of different shades reflecting the characteristics and management challenges unique to each region and vegetation type. Given their place in the spotlight, here’s an attempt to send this ecosystem a little love, provide some important context to the threats it’s facing, and highlight innovative BLM woodland management efforts.

This story is a climate change story, and there’s nothing like climate change to springboard the need for nuance straight into the spotlight. Field-based and remotely sensed data clearly show that pinyon-juniper woodlands are expanding their footprint at the biome scale. Infill has caused widespread, but variable, increases in woodland density within existing woodlands. Yet, drought, wildfires, insects, and disease have killed hundreds of millions of trees in the pinyon-juniper woodlands in portions of the West, particularly in the Colorado Plateau and adjacent states. Pinyon jay populations continue to plummet. Many folks are left wondering what’s going on.

“We used to think about PJ mostly in the context of sage-grouse and fuels management,” said Renee Chi, BLM National Wildlife Biologist. “Although that work was and continues to be highly important, we’re learning that we’ve got to expand our focus in some areas to think about climate resilience. This is particularly important in persistent woodlands, where trees have been growing for thousands of years, but are increasingly dying due to drought and wildfire. In addition, we’re concerned that highly dense woodlands contribute to mortality risk and provide poor wildlife habitat.” 

Pinyon-juniper woodlands are part of a resilient mosaic of habitats across the West. Hikers take in iconic vistas, hunters seek out trophy mule deer, pinyon jays nest in their canopies, and Indigenous peoples collect their pine nuts for sustenance. Tribal identities are closely tied to these woodlands. Wildlife and livestock rely on them for forage and cover. Woodlands also provide many ecosystem services, from carbon storage to water supply. Photo from Paul Burow.

Yet, knowledge is limited in many aspects of pinyon-juniper woodland management. To support BLM staff in answering some questions on this topic, Chi and other BLMers partnered with the Intermountain West Joint Venture and the U.S. Fish and Wildlife Service to compose a report highlighting recent science on primary threats to persistent pinyon-juniper woodlands, identifying the role of changing climate, and featuring new efforts to build pinyon-juniper woodland health and climate resilience. 

“In this report, we walk through what’s going on in persistent pinyon juniper woodlands and the current thinking on how to best manage them in support of a broad suite of benefits, from climate resilience to wildlife habitat to Indigenous use,” said Mariah McIntosh, Science to Implementation Specialist for the Intermountain West Joint Venture and an author on the report.  

BLM is at the frontier of partnering with researchers to learn about woodland management from innovative treatments, and some of this work is highlighted in the report.

In Southwest Colorado, The Tres Rios Field Office, Southwest District Fire Management Unit, and Colorado State Office are working with researchers to experimentally assess the efficacy of different silvicultural treatments in enhancing pinyon-juniper ecosystem health and reducing fire risk on BLM lands. Read the full report to learn more about this work. Photo: Ian Barrett, Fuels Program Lead, Colorado State Office.

After reading the report, we hope you’ll give a little more love to the “PJ” in your corner of the West.