Forest-Range Environmental Study Ecosystems

Forest-Range Environmental Study Ecosystems, known as FRES, is a system for the classification of ecosystems developed by the United States Forest Service as a management tool for the entire lower 48. Thirty four ecosystems were defined for grasslands, forests and woodlands.

Forest and woodland classification

 * FRES 10 White pine - red pine - jack pine
 * FRES 11 Spruce - fir
 * FRES 12 Longleaf - slash pine
 * FRES 13 Loblolly - shortleaf pine
 * FRES 14 Oak pine
 * FRES 15 Oak - hickory
 * FRES 16 Oak - gum - cypress
 * FRES 17 Elm - ash - cottonwood
 * FRES 18 Maple - beech - birch
 * FRES 19 Aspen - birch
 * FRES 20 Douglas-fir
 * FRES 21 Ponderosa pine
 * FRES 22 Western white pine
 * FRES 23 Fir - spruce
 * FRES 24 Hemlock - Sitka spruce
 * FRES 25 Larch
 * FRES 26 Lodgepole pine
 * FRES 27 Redwood
 * FRES 28 Western hardwoods
 * FRES 29 Sagebrush
 * FRES 30 Desert shrub
 * FRES 31 Shinnery
 * FRES 32 Texas savanna
 * FRES 33 Southwestern shrubsteppe
 * FRES 34 Chaparral - mountain shrub
 * FRES 35 Pinyon - juniper

Grassland classification

 * FRES 36 Mountain grasslands
 * FRES 37 Mountain meadows
 * FRES 38 Plains grasslands
 * FRES 39 Prairie
 * FRES 40 Desert grasslands
 * FRES 41 Wet grasslands
 * FRES 42 Annual grasslands

Alpine classification

 * FRES 44 Alpine meadows and barren