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This classification is an update of the 2004 classification of native vegetation of Oregon by Kagan, Christy, Murray and Titus. As before, this classification lists the native plant associations known to occur in Oregon, and includes both successional and climax vegetation types that were part of the presettlement landscape of Oregon and can still be found in the state. It serves as an index to the diversity, distribution and relative rarity of the state's native plant associations, and as a guide to their literature. Published and unpublished reports supported by quantitative data were the primary sources for the classification. In order to accurately identify or describe a plant association, we recommend reading the written descriptions or keys presented in the references cited for each association.

This update incorporates recent classification efforts and scholarship, removes a handful of associations that are no longer present in Oregon, and reconciles the 2004 classification with the United States National Vegetation Classification (USNVC) version 2.02 (2018). The USNVC is a hierarchical plant community classification designed to standardize vegetation classification in the United States (Jennings et al. 2009). It employs a nested system of six physiognomic ranks and two floristically-defined ranks. Only associations, the finest level of that classification are described here. This list includes some newly described or provisional associations not included in the USNVC, which do not have standard USNVC codes.

Plant associations are listed by scientific name, followed by common name. Listings include the global and state rank of each association, a unique code linking to the National Vegetation Classification (USNVC), the Omernik based ecoregions in Oregon in which it occurs, and its distribution in other western states and provinces. Also included is a list of primary references in which the association was described. Sampling methods and concepts of species and associations differ greatly among researchers. Publications from other states or provinces in the Pacific Northwest are included for associations known to occur in, but not described from Oregon.


This work is licensed under CC BY-NC 4.0

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Kaganetal2019_Classification_of_the_Native_Vegetation_of_Oregon.xlsx (285 kB)
Classification of Native Vegetation of Oregon - 2019 Table