2026-10-02 カリフォルニア大学バークレー校（UCB）
米国カリフォルニア州東部シエラ地域のピニョン・ジュニパー林について、先住民が長年観察してきた森林衰退が科学的調査によって裏付けられた。UCバークレーを中心とする「Pinyon Community Climate Action（PiCCA）」ネットワークは、先住民部族、行政機関、研究者、市民が協力し、2024～2025年に森林の健康状態や松かさ生産量を調査した。その結果、調査木の8割以上は健全だった一方、部族が以前から衰退を指摘していた3地域では不健康な木の割合が高かった。また、状態の悪い木は健全な木より松かさ生産量が50％少なく、成熟木は若木より約60％多く生産していた。研究は、気候変動や外来種による影響だけでなく、伝統的生態学的知識を森林管理に組み込む重要性を示す。部族が管理意思決定を共有し、地域住民の参加型モニタリングを進めることが、森林再生と文化的価値の維持につながると提言している。
A collaborative, three-year project involving tribal nations, federal agencies, volunteers, and university researchers is informing stewardship of culturally important pinyon-juniper woodland ecosystems across the Eastern Sierra. Photos by Maggie Riley and Jan Rhoades (left), Andrew Brodhead/Stanford University (center), and Yarrow Syskine (right).
＜関連情報＞
- https://ourenvironment.berkeley.edu/news/tribal-members-saw-pinyon-juniper-woodlands-declining-new-study-confirms-it
- https://besjournals.onlinelibrary.wiley.com/doi/10.1002/pan3.70432
ピニョンマツとジュニパーの森林地帯におけるケアへの道筋：先住民主導のモニタリングと一般市民へのアンケート調査からの知見 Pathways to care in pinyon–juniper woodlands: Insights from Indigenous-led monitoring and a public survey
Diana S. Macias, Thomas Gustie, Paul B. Burow, Brian Adkins, Ana Bacoch, Alexander B. Basaraba, Jacqueline C. Beidl, Benjamin Fillmore, …
People and Nature Published;29 September 2026
DOI:https://doi.org/10.1002/pan3.70432
Abstract
- Conservation decisions often require navigating tensions among ecological, cultural, economic and social priorities. While debates frequently centre on single-species outcomes, less is known about how care for landscapes may contribute to co-stewardship.
- Pinyon–juniper woodlands of California’s Eastern Sierra Nevada provide a compelling case study. These culturally significant, climate-stressed ecosystems are cared for by Tribes of the Eastern Sierra and Great Basin and managed by federal agencies, requiring coordination across knowledge systems and institutional mandates.
- We examined care through an Indigenous-led woodland monitoring network designed to track changes in woodland health and cone production, priorities identified by Tribal Environmental Departments.
- We also conducted a regional household survey to assess residents’ recognition of pinyon–juniper woodlands (via photo) and tested whether species knowledge and demographic factors predicted four composite indices related to care: support for environmental education, environmental responsibility, reciprocity-connectedness to nature, and cultural heritage values.
- Across 516 monitored trees (2024–2025), cone production varied across sites and tree characteristics: trees in poor condition produced approximately 50% fewer cones, and old mature trees produced approximately 60% more cones. Most trees were healthy (83%), yet juvenile density was low (mean = 3.85). Areas of poor health aligned with long-standing observations by Indigenous stewards and highlighted newly assessed areas of stress.
- Household survey respondents (n = 732) correctly identified pinyon–juniper woodlands at high rates (69%), with variation across groups: higher rates were found among men and in individuals with higher educational attainment, liberal political orientation and longer residence in the Eastern Sierra.
- Pinyon–juniper knowledge showed no main effect on care indices but was modestly associated with higher environmental responsibility among respondents with lower climate change knowledge. The four indices were positively correlated and organized into two axes, with climate change knowledge and political orientation as the strongest predictors.
- Together, these findings show that care for pinyon–juniper woodlands operates across social–ecological scales, from on-the-ground stewardship that reasserted Indigenous sovereignty to place-based pathways into environmental responsibility.
- Effective co-stewardship depends on Indigenous leadership, institutional support and attention to how environmental values are socially structured, offering lessons for care-based stewardship under accelerating climate pressures and constrained resources.
