Habitat Evaluation Procedures (HEP) Report; Precious Lands Wildlife Management Area, Technical Report 2000-2003.

The Nez Perce Tribe (NPT) currently manages a 15,325 acre parcel of land known as the Precious Lands Wildlife Management Area that was purchased as mitigation for losses incurred by construction of the four lower Snake River dams. The Management Area is located in northern Wallowa County, Oregon and southern Asotin County, Washington (Figure 1). It is divided into three management parcels--the Buford parcel is located on Buford Creek and straddles the WA-OR state line, and the Tamarack and Basin parcels are contiguous to each other and located between the Joseph Creek and Cottonwood Creek drainages in Wallowa County, OR. The project was developed under the Pacific Northwest Electric Power Planning and Conservation Act of 1980 (P.L. 96-501), with funding from the Bonneville Power Administration (BPA). The acreage protected under this contract will be credited to BPA as habitat permanently dedicated to wildlife and wildlife mitigation. A modeling strategy known as Habitat Evaluation Procedure (HEP) was developed by the U.S. Fish and Wildlife Service and adopted by BPA as a habitat equivalency accounting system. Nine wildlife species models were used to evaluate distinct cover type features and provide a measure of habitat quality. Models measure a wide range of life requisite variables for each species and monitor overall trends in vegetation community health and diversity. One product of HEP is an evaluation of habitat quality expressed in Habitat Units (HUs). This HU accounting system is used to determine the amount of credit BPA receives for mitigation lands. After construction of the four lower Snake River dams, a HEP loss assessment was conducted to determine how many Habitat Units were inundated behind the dams. Twelve target species were used in that evaluation: Canada goose, mallard, river otter, downy woodpecker, song sparrow, yellow warbler, marsh wren, western meadowlark, chukar, ring-necked pheasant, California quail, and mule deer. The U.S. Army Corp of Engineers and the Washington Department of fish and Wildlife subsequently purchased numerous properties to mitigate for the identified Snake River losses. These projects, however, were not sufficient to mitigate for all the HU's lost. The Northwest Power Planning Council amended the remaining 26,774 HU's into their 1994-1995 Fish and Wildlife Program as being unmitigated (NPPC 2000), which allowed the Nez Perce Tribe to contract with BPA to provide HU's through the Precious Lands Project. The Precious Lands project contains a different composition of cover types than those assessed during the lower Snake loss assessment. For example, no mallard or Canada goose habitat exists on Precious Lands but the area does contain conifer forest, which was not present on the area inundated by dam construction. These cover type differences have resulted in a slightly different suite of species for the current HEP assessment. Target species for Precious Lands are downy woodpecker, yellow warbler, song sparrow, California Quail, mule deer, sharp-tailed grouse (brood rearing), west em meadowlark, beaver, and black-capped chickadee. This list is a reflection of the available cover types and the management objectives of the Nez Perce Tribe. For example, chukar was not used in the present assessment because it is an introduced Eurasian game bird that does not provide an accurate representation of the ecological health of the native grasslands it was supposed to represent. Initial model runs using the chukar confirmed this suspicion so the brood-rearing section of the sharp-tailed grouse model was used instead. Additionally, the beaver model was used in place of the river otter model because the otter model used in the loss assessment was not a published model, was overly simplistic, and did not provide an accurate assessment of riparian condition. The beaver model, however, provides a detailed evaluation of overstory class structure that the NPT felt was a good compliment to the yellow warbler and song sparrow models that evaluated understory shrub layers. Overall, such substitutions should result in a more accurate evaluation of the ecological conditions on Precious Lands, and provide better information for decision making. A baseline HEP analysis was initiated on the Precious Lands in 2000, and data collection continued throughout the 2001 and 2002 field seasons. In the future, HEP analysis will be used to evaluate habitat changes resulting from management activities. Repeat surveys will be useful in assessing long-term trends in plant community health, weed encroachment, wildlife limiting factors, habitat degradation, and establishing desired future condition guidelines for the management program