Document Type
Report
Publication Date
11-2016
Subjects
Vegetation -- Soil surveys
Abstract
This classification of historical vegetation map units is based on General Land Office (GLO) surveyors' descriptions of vegetation, independent of modern vegetation classification. Vegetation data in the survey notes include species encountered along the survey lines, distances from section or quarter corners to "witness" or bearing trees, diameters of witness trees, and general descriptions of vegetation along each line. The surveyors were usually consistent in differentiating stands with dissimilar structure or composition, and they routinely segregated forest (“timber”), savanna ("openings"), and woodland ("scattering timber") from prairie. Today, these structural classes are often segregated by percent canopy cover or stand density, but such data were not recorded in GLO notes and must be extrapolated from distances between survey corners and witness trees.
The classification consists of ten vegetation classes (herbaceous upland, upland forest, riparian and wetland forest, shrubland, composition unknown, woodland, prairie, savanna, water, and emergent wetlands excluding wet prairie), each of which is subdivided into several to many subclasses. Use of classes and subclasses as map units in GIS enables users to display data at both coarse and fine scales
Rights
This work is licensed under CC BY-SA 4.0
Persistent Identifier
https://archives.pdx.edu/ds/psu/44281
Citation Details
Christy, John; Alverson, Edward R.; Dougherty, Molly P.; Kolar, Susan C.; Alton, Clifford W.; Hawes, Susan M.; Hickman, Gene; Hiebler, Jennifer A.; and Nielsen, Eric M., "Classification of Historical Vegetation in Oregon and Washington, as Recorded by General Land Office Sureyors" (2016). Institute for Natural Resources Publications. 176.
https://archives.pdx.edu/ds/psu/44281