October 3, 2026.
Long-term observations by members of three Tribal Nations are helping researchers identify areas of declining pinyon-juniper woodland health in California’s Eastern Sierra, while providing information that federal land managers plan to use in future restoration and monitoring.
A new study published in the journal People and Nature is the first research publication resulting from the Pinyon Community Climate Action, or PiCCA, Network, a three-year collaboration involving Tribal Nations, federal agencies, community organizations, volunteers and university researchers.
The study draws on monitoring led by Tribal partners and a household survey of Eastern Sierra residents. Researchers found that more than 80 percent of the surveyed trees appeared healthy, but identified three areas with a high proportion of unhealthy trees. Those areas were locations where Tribal partners had previously identified woodland decline.
The findings provide scientific evidence consistent with observations made by Tribal members over approximately the past decade.
Diana Macias, the study's lead author and a University of California President's Postdoctoral Fellow in the laboratory of UC Berkeley researcher Miranda Redmond, said the results align with the on-the-ground observations made by Tribal partners.
Tribal monitoring came first.
Members of the Bishop Paiute Tribe, Big Pine Paiute Tribe, and Washoe Tribe of Nevada and California have monitored pinyon-juniper woodlands and observed changes in tree health over many years.
The Bishop Paiute Tribe established the Tribal Citizen Wunupu, or Pinyon Pine Nut Tree, Survey in 2018 to track changes in pinyon grove health and pine nut harvests.
The effort was developed with the participation of Monty Bengochia, a former Bishop Paiute tribal historic preservation officer, Tribal Environmental Protection Agency board member and Tribal Council member. The work continues under Thomas Gustie, environmental director for the Bishop Paiute Tribe and a co-author of the new study.
The PiCCA Network built on that work.
The network met quarterly from October 2023 through May 2026 to develop research grounded in Tribal sovereignty and community-based monitoring. Members of the Bishop Paiute and Big Pine Paiute Tribes led monitoring efforts, with assistance from Friends of the Inyo volunteers and students from Palisade Glacier High School. Some monitoring days were open to the broader community while others were limited to Tribal members.
At monitoring sites, participants recorded tree age estimates, tree health, stress indicators and cone production.
What the researchers found.
Monitoring conducted during 2024 and 2025 found substantial differences in cone production among sites, ranging from zero to as many as 60 cones per tree.
Trees in poor condition produced approximately 50 percent fewer cones than healthy trees. Older, mature trees produced approximately 60 percent more cones than younger trees.
Researchers also found that more than 80 percent of the surveyed trees appeared healthy.
However, three areas contained a high proportion of unhealthy trees. One of the areas specifically identified in the study was Westgard Pass, where the results corresponded with areas in which Tribal partners had already reported declining woodland health.
The findings should not be interpreted as evidence that all pinyon-juniper woodlands throughout the Eastern Sierra are declining.
Instead, the research documents specific areas of concern and provides scientific support for observations made by Tribal monitors.
A culturally important ecosystem.
Pinyon-juniper woodlands extend across much of the American West, including portions of California, Nevada, Utah, Colorado, New Mexico and Arizona.
In California, the ecosystems cover more than 3 million acres, according to UC Berkeley. They provide habitat for species including pinyon jays and bobcats. Pinyon pine nuts are also a culturally significant food resource for Tribal communities and, in some areas, an important source of income.
Pinyon-juniper woodlands occupy some of the hottest and driest environments where trees can survive. Water availability is limited, and the trees generally grow slowly.
That makes mature trees particularly important to woodland health and regeneration.
The study's findings that mature trees produce substantially more cones than younger trees underscore the importance of maintaining existing mature stands while also considering reforestation.
A complicated management history.
Pinyon-juniper woodlands have experienced significant changes in both land use and management.
During the mid-to-late nineteenth century, Euro-American settlers harvested pinyon-juniper forests for charcoal used in mining operations as well as for fuel.
More recently, land-management practices in some areas have emphasized restoration of neighboring sagebrush and grassland ecosystems, including habitat associated with the Bi-State sage-grouse. In some cases, that has involved removing pinyon and juniper trees from areas that also have strong cultural importance to Tribal communities.
Researchers say tree removal can have unintended consequences depending on the location and circumstances.
Clearing trees can create opportunities for invasive grasses such as cheatgrass to spread in some areas, potentially affecting fire patterns. Removing mature trees can also reduce wildlife habitat and seed sources.
At the same time, researchers emphasize that more work is necessary to understand the causes of woodland decline and determine the most effective management strategies.
The Forest Service's 2022–2023 monitoring report recorded a sharp increase in dead pinyon pines in portions of the Inyo National Forest, from fewer than 2,000 in 2021 to more than 70,000 in 2022. Most of those deaths occurred in areas important for recreation and cultural use.
Tribal sovereignty and control of information.
An important element of the PiCCA project is the way information is collected and managed.
Each participating Tribal environmental department collects, stores and controls its own data and determines what information it will share.
UC Berkeley researchers do not control the Tribal data. Information made publicly available through the research has been aggregated and locations shifted so that individual groves cannot be identified.
The approach reflects principles of Tribal data sovereignty, allowing Tribal Nations to determine how information concerning their communities and culturally important landscapes is managed.
The project itself grew from Tribal-led monitoring rather than simply applying outside scientific research to Tribal lands and resources.
Reconnecting people with the land.
The project also examined how residents of the Eastern Sierra relate to pinyon-juniper woodlands.
A separate household survey conducted from fall 2024 through spring 2025 included more than 700 residents in Mono, Inyo and Alpine counties. Researchers found that 69 percent of respondents correctly identified pinyon-juniper woodland when shown a photograph.
The researchers found that people who recognized the woodland sometimes reported a stronger sense of environmental responsibility, particularly among residents who considered themselves less informed about climate change.
The findings suggest that familiarity with a particular landscape may contribute to a person's connection to and responsibility for that place.
The researchers also found that respondents with four-year college degrees were more likely to correctly identify pinyon-juniper woodland but reported lower levels of cultural connection and personal responsibility for the land than some other respondents, even after researchers accounted for factors including gender, political views and length of residence.
Researchers say the findings illustrate that people can develop relationships with the land through education, family knowledge, community activities and direct experience.
From monitoring to restoration.
The research is beginning to inform management decisions.
The Inyo National Forest and the Bureau of Land Management's Bishop Field Office plan to use the woodland monitoring information to help inform pinyon pine restoration efforts. They also plan follow-up assessments with forest-health specialists to investigate specific causes of woodland decline.
The Big Pine Paiute Tribe is also undertaking restoration in the Westgard Pass area on land that was excavated more than a decade ago for satellite arrays associated with a university research project.
The Tribe's pinyon woodland specialist is overseeing the restoration, while PiCCA crews conducted monitoring at the site before restoration work began.
The project has also supported cultural activities connected to the woodlands.
Families participated in monitoring activities, while Tribal members shared stories and knowledge connected to camping, hunting and gathering.
In 2025, Tribal members learned to make an Eho, a traditional pine-nut harvesting pole. They later used the poles to gather pine nuts for a Tuba Nuga, or pine-nut dance, and learned to prepare Ikibe, a traditional pine-nut food.
Danelle Gutierrez, historic preservation officer for the Big Pine Paiute Tribe, described the goal as reconnecting Tribal members with the mountains, their resources, songs and language.
A model for collaborative stewardship.
The PiCCA project's funding has ended, and researchers are seeking additional support to continue working with Tribal partners.
For researchers, the project demonstrates the potential value of combining Tribal monitoring with university research and federal land-management expertise.
For Tribal partners, the work is about more than collecting scientific measurements.
It is also about maintaining relationships with culturally important landscapes and passing knowledge between generations.
The study's authors argue that land-management decisions should incorporate the management practices developed by Tribal Nations over generations and that Tribes should have authority in decisions affecting these culturally important landscapes.
The Eastern Sierra project does not suggest that every pinyon-juniper woodland is declining. Instead, it demonstrates how Tribal observations can identify areas of concern, community-based monitoring can document those changes, and collaborative research can provide information for future stewardship and restoration.
The study is dedicated to Monty Bengochia, who died in 2022, in recognition of his work developing woodland monitoring and promoting environmental stewardship.
