A terrestrial ecological system is defined as a group of plant community types that tend to co-occur within landscapes with similar ecological processes, substrates, and/or environmental gradients. A given terrestrial ecological system will typically manifest itself in a landscape at intermediate geographic scales of 10s to 1,000s of hectares and persist for 50 or more years. Ecological processes include natural disturbances such as fire and flooding. Substrates may include a variety of soil surface and bedrock features, such as shallow soils, alkaline parent materials, sandy/gravelling soils, or peatlands. Finally, environmental gradients include local climates, hydrologically defined patterns in coastal zones, arid grassland or desert areas, or montane, alpine or subalpine zones.
To download the below list of ecological systems as a zipped Microsoft Excel file, click here. For detailed descriptions of the ecological systems, please see our final reports or use NatureServe's Ecological System Explorer tool.
| Ecological System Code | Ecological System Description |
| 0 | Background |
| 1 | Disturbed, Non-specific |
| 2 | Recently Burned |
| 11 | Open Water |
| 12 | Perennial Ice/Snow |
| 15 | Conservation Reserve Program |
| 21 | Developed, Open Space |
| 22 | Developed, Low Intensity |
| 23 | Developed, Medium Intensity |
| 24 | Developed, High Intensity |
| 30 | Barren Land (Non-Specific) |
| 31 | Barren Land (Rock/Sand/Clay) |
| 32 | Unconsolidated Shore |
| 33 | Quarries, Mines, Gravel Pits and Oil Wells |
| 41 | Deciduous Forest |
| 42 | Evergreen Forest |
| 43 | Mixed Forest |
| 61 | Orchards Vineyards and Other High Structure Agriculture |
| 71 | Grassland/Herbaceous |
| 80 | Agriculture |
| 81 | Pasture/Hay |
| 82 | Cultivated Cropland |
| 84 | Invasive Annual / Perennial Grassland / Forbland |
| 85 | Recently Burned |
| 88 | High Structure Agriculture |
| 95 | Emergent Herbaceous Wetlands |
| 110 | Urban or build-up land |
| 111 | Residential |
| 112 | Commercial and services |
| 113 | Industrial |
| 114 | Transportation, communications, utilities |
| 115 | Industrial and commercial complexes |
| 116 | Mixed urban or built-up land |
| 117 | Other urban or built-up land |
| 120 | Agricultural land |
| 121 | Cropland and pasture |
| 122 | Orchard, vineyard, nursery, horticultural areas |
| 123 | Confined feeding operations |
| 124 | Other agriculture land |
| 130 | Rangeland |
| 131 | Herbaceous rangeland |
| 132 | Shrub and brush rangeland |
| 133 | Mixed rangeland |
| 140 | Forest land |
| 141 | Deciduous forest land |
| 142 | Evergreen forest land |
| 143 | Mixed conifer hardwood type forest land |
| 144 | Conifer type forest land |
| 145 | Hardwood type forest land |
| 150 | Water |
| 151 | Stream or canal |
| 152 | Perennial Lake or Pond |
| 153 | Reservoir |
| 154 | Bay or estuary |
| 155 | Playa |
| 156 | Intermittent Stream Channel |
| 157 | Ocean |
| 158 | Intermittent Lake or Pond |
| 159 | High Water Line/Gravel/Sand Bar |
| 160 | Wetland |
| 161 | Forested wetland |
| 162 | Non-forested wetland |
| 170 | Barren land |
| 171 | Dry salt flats |
| 172 | Beaches |
| 173 | Sandy area other than beaches |
| 174 | Bare exposed rock |
| 175 | Strip mines, quarries, and gravel pits |
| 176 | Transitional areas |
| 177 | Mixed barren land |
| 180 | Tundra |
| 181 | Shrub and brush tundra |
| 182 | Herbaceous tundra |
| 183 | Bare ground tundra |
| 184 | Wet tundra |
| 185 | Mixed tundra |
| 190 | Perennial snow or ice |
| 191 | Perennial snowfields |
| 192 | Glaciers |
| 1000 | Nonforest (non-specific) |
| 2101 | Undifferentiated Barren Land |
| 2102 | Disturbed/Successional - Recently Chained Pinyon-Juniper |
| 2201 | Open Water (Fresh) |
| 2202 | Open Water (Brackish/Salt) |
| 2301 | Unconsolidated Shore |
| 3116 | Temperate Pacific Intertidal Mudflat |
| 3118 | North Pacific Alpine and Subalpine Bedrock and Scree |
| 3120 | North American Warm Desert Bedrock Cliff and Outcrop |
| 3121 | North American Warm Desert Active and Stabilized Dune |
| 3122 | Temperate Pacific Freshwater Mudflat |
| 3123 | North American Warm Desert Badland |
| 3128 | Inter-Mountain Basins Volcanic Rock and Cinder Land |
| 3129 | Rocky Mountain Cliff, Canyon and Massive Bedrock |
| 3130 | North American Alpine Ice Field |
| 3135 | Rocky Mountain Alpine Bedrock and Scree |
| 3139 | Inter-Mountain Basins Shale Badland |
| 3140 | North Pacific Volcanic Rock and Cinder Land |
| 3143 | North American Warm Desert Pavement |
| 3152 | Inter-Mountain Basins Wash |
| 3155 | North Pacific Montane Massive Bedrock, Cliff and Talus |
| 3157 | North Pacific Active Inland Dune |
| 3158 | North Pacific Coastal Cliff and Bluff |
| 3159 | North Pacific Serpentine Barren |
| 3160 | Inter-Mountain Basins Active and Stabilized Dune |
| 3161 | North American Warm Desert Playa |
| 3164 | Mediterranean California Southern Coastal Dune |
| 3165 | Mediterranean California Northern Coastal Dune |
| 3166 | Mediterranean California Coastal Bluff |
| 3167 | Mediterranean California Serpentine Barrens |
| 3168 | Southern California Coast Ranges Cliff and Canyon |
| 3169 | Central California Coast Ranges Cliff and Canyon |
| 3170 | Klamath-Siskiyou Cliff and Outcrop |
| 3171 | Sierra Nevada Cliff and Canyon |
| 3172 | Mediterranean California Alpine Bedrock and Scree |
| 3173 | Inter-Mountain Basins Cliff and Canyon |
| 3174 | Columbia Plateau Ash and Tuff Badland |
| 3177 | North Pacific Maritime Coastal Sand Dune and Strand |
| 3179 | Inter-Mountain Basins Playa |
| 3180 | North American Warm Desert Volcanic Rockland |
| 3183 | Colorado Plateau Mixed Bedrock Canyon and Tableland |
| 4101 | North Pacific Oak Woodland |
| 4103 | Northern Rocky Mountain Western Larch Savanna |
| 4104 | Rocky Mountain Aspen Forest and Woodland |
| 4105 | Rocky Mountain Bigtooth Maple Ravine Woodland |
| 4201 | Central and Southern California Mixed Evergreen Woodland |
| 4202 | California Coastal Redwood Forest |
| 4203 | Colorado Plateau Pinyon-Juniper Woodland |
| 4204 | Columbia Plateau Western Juniper Woodland and Savanna |
| 4205 | East Cascades Mesic Montane Mixed-Conifer Forest and Woodland |
| 4206 | Great Basin Pinyon-Juniper Woodland |
| 4207 | Inter-Mountain Basins Subalpine Limber-Bristlecone Pine Woodland |
| 4208 | Klamath-Siskiyou Lower Montane Serpentine Mixed Conifer Woodland |
| 4209 | Klamath-Siskiyou Upper Montane Serpentine Mixed Conifer Woodland |
| 4210 | Madrean Encinal |
| 4211 | Madrean Pine-Oak Forest and Woodland |
| 4212 | Madrean Pinyon-Juniper Woodland |
| 4214 | Mediterranean California Dry-Mesic Mixed Conifer Forest and Woodland |
| 4215 | Mediterranean California Mesic Mixed Conifer Forest and Woodland |
| 4216 | Mediterranean California Mixed Oak Woodland |
| 4217 | Mediterranean California Lower Montane Black Oak-Conifer Forest and Woodland |
| 4218 | California Montane Jeffrey Pine-(Ponderosa Pine) Woodland |
| 4219 | Mediterranean California Red Fir Forest |
| 4220 | Mediterranean California Subalpine Woodland |
| 4221 | Mediterranean California Mesic Serpentine Woodland and Chaparral |
| 4222 | North Pacific Dry Douglas-fir-(Madrone) Forest and Woodland |
| 4223 | North Pacific Hypermaritime Sitka Spruce Forest |
| 4224 | North Pacific Maritime Dry-Mesic Douglas-fir-Western Hemlock Forest |
| 4225 | North Pacific Maritime Mesic Subalpine Parkland |
| 4226 | North Pacific Maritime Mesic-Wet Douglas-fir-Western Hemlock Forest |
| 4228 | North Pacific Mountain Hemlock Forest |
| 4229 | North Pacific Mesic Western Hemlock-Silver Fir Forest |
| 4230 | Mediterranean California Mixed Evergreen Forest |
| 4231 | Northern California Mesic Subalpine Woodland |
| 4232 | Northern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest |
| 4233 | Northern Rocky Mountain Subalpine Woodland and Parkland |
| 4234 | Northern Rocky Mountain Mesic Montane Mixed Conifer Forest |
| 4236 | Rocky Mountain Foothill Limber Pine-Juniper Woodland |
| 4237 | Rocky Mountain Lodgepole Pine Forest |
| 4238 | Southern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest and Woodland |
| 4239 | Southern Rocky Mountain Mesic Montane Mixed Conifer Forest and Woodland |
| 4240 | Northern Rocky Mountain Ponderosa Pine Woodland and Savanna |
| 4241 | Southern Rocky Mountain Ponderosa Pine Woodland |
| 4242 | Rocky Mountain Subalpine Dry-Mesic Spruce-Fir Forest and Woodland |
| 4242 | Rocky Mountain Subalpine Dry-Mesic Spruce-Fir Forest and Woodland |
| 4243 | Rocky Mountain Subalpine Mesic Spruce-Fir Forest and Woodland |
| 4244 | Rocky Mountain Subalpine-Montane Limber-Bristlecone Pine Woodland |
| 4245 | Sierra Nevada Subalpine Lodgepole Pine Forest and Woodland |
| 4266 | Middle Rocky Mountain Montane Douglas-fir Forest and Woodland |
| 4267 | Rocky Mountain Poor-Site Lodgepole Pine Forest |
| 4268 | California Coastal Closed-Cone Conifer Forest and Woodland |
| 4269 | Sierran-Intermontane Desert Western White Pine-White Fir Woodland |
| 4271 | North Pacific Hypermaritime Western Red-cedar-Western Hemlock Forest |
| 4272 | North Pacific Dry-Mesic Silver Fir-Western Hemlock-Douglas-fir Forest |
| 4301 | East Cascades Oak-Ponderosa Pine Forest and Woodland |
| 4302 | Inter-Mountain Basins Aspen-Mixed Conifer Forest and Woodland |
| 4303 | Inter-Mountain Basins Curl-leaf Mountain Mahogany Woodland and Shrubland |
| 4304 | North Pacific Broadleaf Landslide Forest and Shrubland |
| 4329 | North Pacific Wooded Volcanic Flowage |
| 4333 | North Pacific Lowland Mixed Hardwood-Conifer Forest and Woodland |
| 5201 | Colorado Plateau Mixed Low Sagebrush Shrubland |
| 5202 | Columbia Plateau Scabland Shrubland |
| 5203 | Inter-Mountain Basins Mat Saltbush Shrubland |
| 5204 | Mediterranean California Alpine Fell-Field |
| 5205 | North Pacific Dry and Mesic Alpine Dwarf-Shrubland, Fell-field and Meadow |
| 5206 | North Pacific Mesic Low Shrubland |
| 5207 | Rocky Mountain Alpine Dwarf-Shrubland |
| 5208 | Rocky Mountain Alpine Tundra/Fell-field/Dwarf-shrub Map Unit |
| 5251 | Chihuahuan Creosotebush, Mixed Desert and Thorn Scrub |
| 5255 | Colorado Plateau Blackbrush-Mormon-tea Shrubland |
| 5256 | Great Basin Xeric Mixed Sagebrush Shrubland |
| 5257 | Inter-Mountain Basins Big Sagebrush Shrubland |
| 5258 | Inter-Mountain Basins Mixed Salt Desert Scrub |
| 5259 | Mojave Mid-Elevation Mixed Desert Scrub |
| 5260 | North Pacific Avalanche Chute Shrubland |
| 5261 | North Pacific Montane Shrubland |
| 5263 | Rocky Mountain Lower Montane-Foothill Shrubland |
| 5264 | Sonora-Mojave Creosotebush-White Bursage Desert Scrub |
| 5265 | Sonora-Mojave Mixed Salt Desert Scrub |
| 5268 | Sonoran Mid-Elevation Desert Scrub |
| 5269 | Southern California Coastal Scrub |
| 5270 | Southern Colorado Plateau Sand Shrubland |
| 5301 | Apacherian-Chihuahuan Mesquite Upland Scrub |
| 5302 | California Maritime Chaparral |
| 5303 | California Mesic Chaparral |
| 5304 | California Montane Woodland and Chaparral |
| 5305 | California Xeric Serpentine Chaparral |
| 5308 | Colorado Plateau Pinyon-Juniper Shrubland |
| 5309 | Great Basin Semi-Desert Chaparral |
| 5310 | Mogollon Chaparral |
| 5311 | Northern and Central California Dry-Mesic Chaparral |
| 5312 | Northern Rocky Mountain Montane-Foothill Deciduous Shrubland |
| 5313 | Rocky Mountain Gambel Oak-Mixed Montane Shrubland |
| 5314 | Sonora-Mojave Semi-Desert Chaparral |
| 5315 | Sonoran Paloverde-Mixed Cacti Desert Scrub |
| 5316 | Southern California Dry-Mesic Chaparral |
| 5326 | Northern Rocky Mountain Subalpine Deciduous Shrubland |
| 5327 | Northern Rocky Mountain Avalanche Chute Shrubland |
| 5401 | California Central Valley Mixed Oak Savanna |
| 5402 | California Coastal Live Oak Woodland and Savanna |
| 5403 | California Lower Montane Blue Oak-Foothill Pine Woodland and Savanna |
| 5404 | Inter-Mountain Basins Juniper Savanna |
| 5405 | Madrean Juniper Savanna |
| 5407 | Southern California Oak Woodland and Savanna |
| 5409 | Willamette Valley Upland Prairie and Savanna |
| 5425 | Klamath-Siskiyou Xeromorphic Serpentine Savanna and Chaparral |
| 5426 | Northern Rocky Mountain Foothill Conifer Wooded Steppe |
| 5450 | Apacherian-Chihuahuan Semi-Desert Grassland and Steppe |
| 5452 | Columbia Plateau Steppe and Grassland |
| 5453 | Columbia Plateau Low Sagebrush Steppe |
| 5454 | Inter-Mountain Basins Big Sagebrush Steppe |
| 5455 | Inter-Mountain Basins Montane Sagebrush Steppe |
| 5456 | Inter-Mountain Basins Semi-Desert Shrub Steppe |
| 5457 | Northern California Coastal Scrub |
| 7101 | California Central Valley and Southern Coastal Grassland |
| 7102 | California Mesic Serpentine Grassland |
| 7103 | California Northern Coastal Grassland |
| 7106 | Columbia Basin Foothill and Canyon Dry Grassland |
| 7107 | Inter-Mountain Basins Semi-Desert Grassland |
| 7108 | Mediterranean California Alpine Dry Tundra |
| 7109 | Mediterranean California Subalpine Meadow |
| 7110 | North Pacific Montane Grassland |
| 7112 | Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland |
| 7113 | Northern Rocky Mountain Subalpine-Upper Montane Grassland |
| 7115 | Columbia Basin Palouse Prairie |
| 7116 | Rocky Mountain Alpine Fell-Field |
| 7117 | Rocky Mountain Dry Tundra |
| 7118 | Rocky Mountain Subalpine-Montane Mesic Meadow |
| 7119 | Southern Rocky Mountain Montane-Subalpine Grassland |
| 7157 | North Pacific Alpine and Subalpine Dry Grassland |
| 7161 | North Pacific Hypermaritime Shrub and Herbaceous Headland |
| 7162 | North Pacific Herbaceous Bald and Bluff |
| 8311 | Ruderal Wetland |
| 8401 | Introduced Upland Vegetation - Treed |
| 8402 | Introduced Upland Vegetation - Shrub |
| 8403 | Introduced Upland Vegetation - Annual and Biennial Forbland |
| 8404 | Introduced Upland Vegetation - Annual Grassland |
| 8405 | Introduced Upland Vegetation - Perennial Grassland |
| 8406 | Introduced Riparian and Wetland Vegetation |
| 8407 | Introduced Upland Vegetation - Perennial Grassland and Forbland |
| 8480 | Introduced Riparian Vegetation |
| 8490 | Introduced Wetland Vegetation |
| 8500 | Recently Burned Vegetation |
| 8501 | Recently burned forest |
| 8502 | Recently burned grassland |
| 8503 | Recently burned shrubland |
| 8506 | Cultivated Crops and Irrigated Agriculture |
| 8601 | Harvested Forest - Northwestern Conifer Regeneration |
| 8602 | Harvested forest-shrub regeneration |
| 8603 | Harvested Forest - Grass/Forb Regeneration |
| 8604 | Harvested forest-herbaceous regeneration |
| 9101 | California Central Valley Riparian Woodland and Shrubland |
| 9103 | Inter-Mountain Basins Greasewood Flat |
| 9104 | Inter-Mountain Basins Montane Riparian Systems |
| 9106 | North Pacific Lowland Riparian Forest and Shrubland |
| 9108 | North Pacific Montane Riparian Woodland and Shrubland |
| 9109 | Rocky Mountain Montane Riparian Systems |
| 9111 | Northern Rocky Mountain Conifer Swamp |
| 9151 | North American Warm Desert Wash |
| 9155 | Northern Rocky Mountain Lower Montane Riparian Woodland and Shrubland |
| 9156 | Rocky Mountain Lower Montane Riparian Woodland and Shrubland |
| 9166 | North Pacific Bog and Fen |
| 9168 | Great Basin Foothill and Lower Montane Riparian Woodland and Shrubland |
| 9170 | Columbia Basin Foothill Riparian Woodland and Shrubland |
| 9171 | Rocky Mountain Subalpine-Montane Riparian Woodland |
| 9172 | North American Warm Desert Lower Montane Riparian Woodland and Shrubland |
| 9173 | North Pacific Shrub Swamp |
| 9178 | North American Warm Desert Riparian Mesquite Bosque |
| 9182 | North American Warm Desert Riparian Woodland and Shrubland |
| 9187 | Rocky Mountain Subalpine-Montane Riparian Shrubland |
| 9188 | Mediterranean California Alkali Marsh |
| 9190 | North Pacific Hardwood-Conifer Swamp |
| 9217 | Rocky Mountain Alpine-Montane Wet Meadow |
| 9219 | Temperate Pacific Freshwater Aquatic Bed |
| 9220 | North Pacific Intertidal Freshwater Wetland |
| 9221 | Willamette Valley Wet Prairie |
| 9222 | North American Arid West Emergent Marsh |
| 9225 | North Pacific Hardpan Vernal Pool |
| 9230 | North Pacific Maritime Eelgrass Bed |
| 9231 | Columbia Plateau Vernal Pool |
| 9233 | Northern Columbia Plateau Basalt Pothole Ponds |
| 9234 | Rocky Mountain Subalpine-Montane Fen |
| 9235 | Inter-Mountain Basins Interdunal Swale Wetland |
| 9248 | Mediterranean California Subalpine-Montane Fen |
| 9250 | Northern California Volcanic Vernal Pool |
| 9251 | Northern California Claypan Vernal Pool |
| 9255 | Mediterranean California Serpentine Fen |
| 9260 | Temperate Pacific Freshwater Emergent Marsh |
| 9262 | Mediterranean California Coastal Interdunal Wetland |
| 9264 | Modoc Basalt Flow Vernal Pool |
| 9265 | Temperate Pacific Montane Wet Meadow |
| 9266 | Mediterranean California Eelgrass Bed |
| 9281 | Temperate Pacific Tidal Salt and Brackish Marsh |
| 9297 | Inter-Mountain Basins Alkaline Closed Depression |
| 9321 | Columbia Plateau Silver Sagebrush Seasonally Flooded Shrub-Steppe |
| 9325 | Mediterranean California Serpentine Foothill and Lower Montane Riparian Woodland and Seep |
| 9330 | Mediterranean California Foothill and Lower Montane Riparian Woodland |
| 10000 | Notaly plots |
| 20008 | Agriculture |