Pinyon-juniper extent maps (Draft v1 | July 2026)
The Pinyon-Juniper Mapping Project (PJMap) is developing a suite of spatial products to improve our understanding of pinyon-juniper (PJ) woodlands and support management across the western United States. As an initial step, the PJMap science team developed three complementary maps describing the current, potential, and historical distribution of PJ woodlands. These layers were created through a collaborative process to help define the ecological framework for the project and establish a consistent foundation for future mapping efforts.
These map products classify a pinyon-juniper woodland as any area that contains at least one of the PJ species defined here, either directly through species-specific data sources (FIA) or products that derive PJ woodlands through combined sources (e.g. LANDFIRE, RAP).
Together, these maps represent different aspects of PJ distribution:
- Current distribution – Areas with both the environmental potential to support pinyon-juniper woodlands and existing canopy cover (≥4%) of a subset of pinyon and juniper species. This layer represents a snapshot of existing PJ woodlands.
- Current potential distribution – Areas capable of supporting pinyon-juniper woodlands under current environmental conditions, regardless of whether woodlands are currently present. This layer broadly represents the site potential of PJ systems today.
- Historical distribution – An estimate of the distribution of pinyon-juniper woodlands prior to widespread Euro-American settlement. This layer provides historical context for understanding long-term woodland dynamics and change.
Rather than relying on a single dataset, these products integrate multiple complementary data sources to provide a more comprehensive representation of PJ distribution across the West. They are intended to serve both as standalone products—particularly for understanding current woodland extent for management, fire and fuels planning, and restoration—and as the foundation for future products describing ecological integrity, woodland condition, and management opportunities.
Status: These layers are preliminary (Draft v1; July 2026) and are under active development. They reflect ongoing discussions and are intended to inform the project’s analytical framework and mapping process. We welcome feedback as these products continue to evolve.
