Looking at Lime Hills from Stony River, Alaska
BLM/Alaska Photo by Piia Kortsalo
Looking at Lime Hills from Stony River, Alaska

Yukon Kuskokwim Rapid Ecoregional Assessment (REA)

Status | Location and Setting | Management Questions | Conservation Elements | Change Agents | Data, Maps, and Models | Memos and Reports

REA Status  
The Yukon Kuskokwim REA was initiated in August 2012 and is scheduled for completion in mid-2014. REA Task 1 (the refinement of management questions, conservation elements, and change agents) was completed in February 2013. Currently, the list of datasets to be used in the assessment as well as the methods, models, and tools are being developed. These tasks are scheduled to be completed by May 2013. See the Memos and Reports section for a list of scheduled tasks and to download the completed documents.


States in the Yukon:
Alaska
 

Contact: Project Manager
for more information


  Location Map

Yukon Kuskokwim REA Map

Location and Setting
The Yukon Kuskokwim REA in Interior Alaska encompasses three distinct ecoregions: the Yukon Lowlands, the Kuskokwim Mountains, and the Lime Hills (YKL). Combined, these ecoregions total nearly 41 million acres managed by seven major landowners.

The Yukon Lowlands are part of an extensive wetland system associated with the lower stretches of the Yukon and Koyukuk rivers in the western regions of Interior Alaska. White spruce and balsam poplar line the major rivers. They surround tall stands of alder and willow which grow throughout the floodplains and river bars. Wet sedge meadows and aquatic vegetation fill sloughs and oxbow ponds. Black spruce woodlands, birch-ericaceous shrubs and sedge-tussock bogs cover areas underlain with permafrost.

The Kuskokwim Mountains are old, low, rolling mountains south and east of the Yukon Lowlands. These mountains are underlain with thin to moderately thick permafrost. White spruce, white birch, and trembling aspen cover the uplands and black spruce and tamarack fill the lowlands.

The Lime Hills are glacially dissected mountains descending from the west side of the Alaska Range and south of the Kuskokwim Mountains. This region’s heavy glaciation resulted in sharp mountain ridges with steep headwalls and broad U-shaped valleys. Shrub communities of willow, birch and alder dominate the vegetation. Valley bottoms and mountains slopes are spruce forests and woodlands.

These three ecoregions support large wildlife populations of moose, bear, beavers, furbearers and scattered caribou herds; waterfowl; and, important runs of sockeye, Chinook, chum and coho salmon in the larger rivers. 

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Management Questions
Management questions guide an ecoregional assessment. Successful management questions address specific information needs in order to produce meaningful information for future management actions. Sixty-four management questions were selected for the Yukon Kuskokwim REA that align along these 13 broad themes:

  • Land cover
  • Wildlife
  • Aquatics
  • Soil dynamics
  • Hydrology
  • Climate
  • Fire
  • Invasive species
  • Socioeconomics
  • Subsistence
  • Sport and commercial hunting and fishing
  • Land use
  • Traditional ecological knowledge

See the Memos and Reports section to view Memorandum 1, which outlines the selection process and provides the full list of management questions.

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Conservation Elements
Conservation elements are renewable resources of high conservation interest within an ecoregion. This REA will assess the current condition and forecasted future condition of two types of conservation elements:

  • “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.

Thirty conservation elements were selected for assessment in this REA: nine coarse-filter terrestrial elements, five coarse-filter aquatic elements, nine fine-filter terrestrial elements, and seven fine-filter aquatic elements. See the Memos and Reports section to view Memorandum 1, which provides the full list of conservation elements.

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Change Agents
A key purpose of this REA is to understand the influences of significant widespread change agents on the natural resources of the ecoregions in the Yukon Kuskokwim REA. Change agents are features or phenomena that have the potential to affect the size, condition, and landscape context of conservation elements. The following change agents will be assessed:

  • Climate change
  • Fire
  • Invasive species
  • Insect defoliators and disease
  • Anthropogenic uses

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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.


Yukon Kuskokwim (YKL) REA Memos and Reports

Description

Document Link

Management questions, conservation elements, and change agentsTask 1 Final Memorandum (PDF)
Datasets for analysis 
Analytical models and tools 
REA work planTask 4 Final Workplan
Preliminary findings for review 
REA report, maps, and supporting documents 
REA Land Status MapLand Status Map