Home/Ecosystems/ Glacier and Ice Field

Glacier and Ice Field

EVT 7735North American Glacier and Ice Field

CES100.728GNRSnow-iceSnow-ice

Summary

This widespread ecological system is composed of unvegetated landscapes of annual/perennial ice and snow in the North American arctic, and south into the highest elevations of the Rocky Mountains, Pacific coastal ranges, and the Sierra Madre of Mexico. They occur where snowfall accumulation exceeds melting. The primary ecological processes include snow/ice retention, wind desiccation, and permafrost. The snowpack/ice field never melts or, if so, then for only a few weeks. In places the ice fields are extensive, covering huge areas, while in the alpine, ice fields are part of the alpine mosaic consisting of alpine bedrock and scree, tundra dry meadow, wet meadow, fell-fields, and dwarf-shrubland. There are no vascular plants occurring in this system; biotic composition may include algal blooms, insect communities, and birds or mammals foraging on the insects.

Source: NatureServe Explorer

Distribution

This ecological system is found throughout North America where high latitude or altitude results in permanent ice and snow fields, from the arctic and boreal regions south into the mountains of Alaska south and east through the cordillera of the Cascades and the Rocky Mountains. It also occurs in the alpine areas of the Sierra Madre in Mexico.

Source: NatureServe Explorer

Ecologically Associated Animals (3)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Birds (3)

Common Name	Scientific Name	G-Rank
Black Rosy-Finch	Leucosticte atrata	G4
Brown-capped Rosy-Finch	Leucosticte australis	G4
Gray-crowned Rosy-Finch	Leucosticte tephrocotis	G5

Source: NatureServe Ecological System assessment

State Conservation Ranks (7)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

State	S-Rank
AK	SNR
CO	SNR
ID	SNR
MT	SNR
OR	SNR
WA	SNR
WY	SNR

Roadless Areas (6)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

California (2)

Area	Forest	Coverage	Hectares
Mt. Shasta A	Shasta-Trinity National Forest	3.7%	10.08
Hall Natural Area	Inyo National Forest	2.1%	44.1

Montana (1)

Area	Forest	Coverage	Hectares
Crazy Mountain	Gallatin National Forest	1.4%	477.9

Oregon (1)

Area	Forest	Coverage	Hectares
Mt. Hood Additions	Mt. Hood National Forest	2.2%	118.62

Washington (1)

Area	Forest	Coverage	Hectares
White Chuck Mountain	Mt Baker-Snoqualmie National Forest	1.4%	33.39

Wyoming (1)

Area	Forest	Coverage	Hectares
Sulphur Creek	Shoshone National Forest	0.5%	65.52

Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.