The Beaufort Coastal Plain is a treeless, wind-swept plain ascending from the Beaufort Sea coast southward to the foothills of the Brooks Range. A dry polar climate dominates the region resulting in short cool summers and long cold winters. The proximity to the Arctic Ocean and abundant sea ice contribute to the cool and frequently foggy summers. Permafrost is continuous across the region, except under large rivers and thaw lakes. Permafrost and frost processes create unique surface features such as pingos, ice-wedge polygons and oriented thaw lakes. Permafrost also prevents surface drainage so soils are typically saturated and have thick organic horizons. Due to the abundance of thaw lakes and saturated soils, nearly the entire region supports wetland communities and is important for a wide variety of shorebirds, ducks, geese and swans. Vegetation is dominated by wet sedge tundra on flooded soils and by tussock tundra and sedge-Dryas tundra on gentle ridges. The coastal plain supports large caribou herds and is an important calving area. The plain also supports populations of arctic foxes, gray wolves, brown bears, muskoxen, lemmings, and arctic ground squirrels. Polar bears occasionally den on the coastal plain.
The Brooks Foothills are gently rolling hills and broad exposed ridges that extend from the northern edge of the Brooks Range. A dry polar climate dominates the foothills, but is somewhat warmer and wetter than the Beaufort Coastal Plain. The surface is also underlain by thick continuous permafrost and results in saturated soils and a thick organic horizon. Many braided streams and rivers of clear water exist in the foothills and support arctic char and arctic grayling. The vegetation is a vast expanse of mixed shrub-sedge tussock tundra, interspersed with willow thickets along rivers and drainages. Dryas tundra dominates ridges. The area is important to caribou, muskox, arctic ground squirrels, peregrine falcons, wolves and brown bears.
The Brooks Range is an east-west trending mountain range with high-energy streams and rivers cutting through narrow ravines and steep headwalls. The range also has a dry polar climate with air temperatures decreasing rapidly with rising elevation. Valleys and lower mountain slopes on the north side of the range are covered with mixed shrub-sedge tussock tundra and willow thickets surround rivers and streams. Alpine tundra and barrens dominate at higher elevations along the entire crest of the range. Dall sheep, gray wolves, brown bears, marmots and caribou inhabit the mountains. Arctic grayling are found in groundwater fed springs and streams.
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Management questions guide an ecoregional assessment. Management questions address specific information needs in order to produce meaningful information for future management actions. Management questions for the North Slope ecoregions align along these nine broad themes:
- Native Plant Communities
- Aquatic Resources
- Wildlife Resources
- Climate and Permafrost
- Invasive Species
- Energy Development
- Regional Socioeconomics
The management questions for the North Slope REA will be presented in the Task 1 Final Memorandum.
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Conservation elements are renewable resources of high conservation interest within an ecoregion. The North Slope REA will assess the current condition and forecasted future condition of the predominant terrestrial and aquatic ecosystems and species of regional concern within two broad categories:
- “Coarse-filter” conservation elements, which typically include all of the major ecosystem types within the assessment landscape, and represent all of the predominant natural ecosystem functions and services in the ecoregions;
- and “Fine-filter” conservation elements, which complement the first set of elements by including a limited subset of focal species assemblages and individual species.
A full list and explanation of the conservation elements will be included in the Task 1 Final Memorandum.
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A key purpose of this REA is to understand the influences of features or phenomena that have the potential to affect the size, condition and landscape context of conservation elements present in the North Slope ecoregions. These change agents are likely to be included in the assessment:
- Climate change
- Invasive species
A more complete discussion of the change agents will be included in the Task 1 Final Memorandum.
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Data, Maps, and Models
Geospatial data, maps, and models used in and produced by the REAs will be made available to the public upon final completion of each individual assessment.
Memos and Reports
For each REA, there is a series of memos which are supplemental documents to the final report. Memos document the major tasks and decision points made during the assessments and provide pertinent background information necessary to understand the justification and methods used during the assessment. As memos and the final report are completed, they can be downloaded through the table below.
North Slope (NOS) REA Memos and Reports