The Dominant Overstory Vegetation Map represents actual vegetation recorded by LANDSAT imagery taken primarily in July of 1988. Current vegetation patterns may be slightly different due to vegetation’s successional stages and recent timber harvest. Most vegetation is not uniform but a composite of different species.  A mapping unit is given to a single vegetation classification when at least 60% of the area is covered by one vegetation type.  For areas where there are two primary vegetation types the classification is referred to as a mosaic and indicates that two vegetation types are approximately equal in area.  The nominal minimum mapping unit is 320 acres, although most mapped areas are larger.  

Detailed information from Manual of Oregon Actual Vegetation (1992) by Jimmy Kagan is listed below for each vegetation classification.

• Glossary of Acronyms

• Urban / Industrial

• Agricultural Cropland / Pastureland

• Alpine Communities

• Subalpine Lodgepole Pine Forest and Woodland

• Mountain Hemlock Forest

• Mountain Hemlock Parkland

• Mountain Hemlock - True Fir - Lodgepole Pine Forest

• Mixed Conifer and Broadleaf Deciduous Forest

• Silver Fir - Western Hemlock - Noble Fir Forest

• Douglas Fir - Western Hemlock - Grand Fir Forest

• Douglas Fir - Oregon White Oak Forest and Woodland

• Oregon Ash - Black Cottonwood - Bottomland Pasture Mosaic / Ponderosa Pine Forest and Woodland

• Oregon Ash - Black Cottonwood - Bottomland Pasture Mosaic
  

The data for the Dominant Overstory Vegetation Map was taken from the Oregon Gap Analysis Program directed by the Idaho Cooperative Fish & Wildlife Research Unit, University of Idaho, in cooperation with the Oregon Department of Fish and Wildlife and the Oregon Natural Heritage Program. The data and more detailed descriptions can be found at Oregon Geospatial Data Clearinghouse under Vegetation/species Idaho F&W Gap Vegetation - 1:250,000.

last updated 11/22/00
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