The biologically significant unit (BSU) is a geographical/spatial area within greater sage-grouse habitat that contains relevant and important habitats which is used as the basis for comparative calculations to support evaluation of changes to habitat. This BSU unit, or subset of this unit is used in the calculation of the anthropogenic disturbance threshold and in the adaptive management habitat trigger. While the BSU defines the geographic extent and scale of these two measures, how they are calculated differs based on the specific measures to reflect appropriate assessment and evaluation as supported by scientific literature.
Biologically Significant Unit (BSU)
There are 10 BSUs for the Idaho and Southwestern Montana GRSG EIS sub-region. For the Idaho and Southwestern Montana Greater Sage-Grouse Plan Amendment FEIS the biologically significant unit is defined as: a geographical/spatial area within greater sage-grouse habitat that contains relevant and important habitats which is used as the basis for comparative calculations to support evaluation of changes to habitat.
Idaho: BSUs include all of the Idaho Fish and Game modeled nesting and delineated winter habitat, based on 2011 inventories within Priority and/or Important Habitat Management Area of the Administrative Draft Proposed Plan (ADPP)) within a Conservation Area. There are eight BSUs for Idaho identified by Conservation Area and Habitat Management Area: Idaho Desert Conservation Area - Priority; Idaho Desert Conservation Area - Important; Idaho Mountain Valleys Conservation Area - Priority; Idaho Mountain Valleys Conservation Area - Important; Idaho Southern Conservation Area - Priority; Idaho Southern Conservation Area - Important; Idaho West Owyhee Conservation Area - Priority; and Idaho West Owyhee Conservation Area - Important.
Raft River : Utah portion of the Sawtooth National Forest, 1 BSU. All of this areas was defined as Priority habitat in the ADPP. Raft River - Priority
Montana: All of the Priority Habitat Management Area. 1 BSU. SW Montana Conservation Area - Priority
Habitat Management Area
The Habitat Management Area is a coordinated delineation of sage-grouse Management Areas between Idaho BLM, U.S. Forest Service, State of Idaho and the U.S. Fish and Wildlife Service, based on considerations of sage-grouse occupancy, landscape, habitat and land use/adaptive management opportunities. Priority Areas have the highest conservation value based on various sage-grouse population and habitat considerations and reflect the most restrictive management designed to promote sage-grouse conservation. Important zones are closely aligned with Priority, but management is somewhat less restrictive, providing additional management flexibility. The General management zone designation is the least restrictive due to generally lower occupancy of sage-grouse and more marginal habitat conditions.
Idaho-Montana Greater Sage-Grouse Conservation Areas for the Idaho and Southwestern Greater Sage-Grouse (GRSG) Final Environmental Impact Statement (FEIS). The Conservation Areas are seamless and cover the extent of the Idaho-SW Montana GRSG EIS. They include non-habitat as well as habitat identified in ADPP alternatives and in Alternatives A-F. The Sage-grouse Conservation Areas are intended to be used for summarizing sage-grouse habitat and form the geographic basis for evaluating disturbance density and adaptive management strategies. The Idaho Governor's Conservation Areas were used as the foundation for this layer.
There are five Greater Sage-Grouse Conservation Areas in the EIS boundary. They include non-habitat as well as habitat: Idaho Mountain Valleys Conservation Area, Idaho Desert Conservation Area, Idaho Southern Conservation Area, Idaho West Owyhee Conservation Area, and the Southwestern Montana Conservation Area. The Raft River Unit in Utah managed by the Sawtooth National Forest was grouped with the Idaho Southern Conservation Area. The areas in Southwestern Montana were grouped as the Southwestern Montana Conservation Area. Metadata for the Conservation Areas can be found in the description of Conservation Areas used in the FEIS.
Anthropogenic Disturbances include :
Oil and Gas Well and Development Facilities
Geothermal Development Facilities
Active Locatable, Leasable and Saleable Developments
Other Vertical Structures
Other Developed Righs-of-Ways
Coal Bed Methance Ponds
Nuclear Energy Facilities