Inventorying, Classifying, and Correlating Juniper and Pinyon Communities To Soils in Western United States

U.S. Department of Agriculture
Natural Resoures Conservation Service
Grazing Lands Technology Institute


This publication provides general guidance for the inventorying, classifying, and correlation of juniper and pinyon (or piñon) into ecological sites. These guidelines are based on the ecological site descriptions for rangelands and forest lands. These guidelines are to be used during soil survey operations and any time ecological site development and revision is taking place. Soil surveys on western rangelands and forest lands are normally completed with each major soil component correlated to a rangeland or forest land ecological site. As part of the National Cooperative Soil Survey, soil surveys include the characterization and classification of plant communities growing on each soil. The National Cooperative Soil Survey is a joint effort of the U.S. Department of Agriculture and other Federal agencies, state agencies including the Agricultural Experiment Stations and local agencies. USDA’s Natural Resources Conservation Service (NRCS) coordinates the Federal part. In the juniper or pinyon plant transitions between climax forest land and rangeland often exhibit vegetation that is of recent derivation and may not have been typical of the site when natural ecological processes were functioning on the site. The changes in the past 150 to 300 years often mask the potential plant communities of the sites and can create inconsistencies in inventory processes. Knowing where pinyon or juniper communities, or both, have increased on rangeland, or invaded into adjacent rangeland is essential for understanding their ecology. The land also must be managed within its capabilities and limitations.