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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. ^[1] Thirty four ecosystems were defined for grasslands, forests, and woodlands. ^[1]

Contents

• Forest and woodland classification
• Grassland classification
• Alpine classification
• Notes

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

Notes