Primary purpose
To estimate the bird species composition and richness of lowland wetlands and riparian areas larger than 0.1 acre located within the Colorado Plateau. May be used in a variety of situations (e.g., mitigation calculations, detecting impaired wetland quality, targeting habitat enhancements, and wildlife-based classification of wetland habitats).
Expertise needed
Consultants and employees of government agencies, who have at least a Bachelor’s degree in one of the environmental disciplines. Users must be able to recognize a few of the major vegetation types of the Colorado Plateau.
Applicable habitat types
Any lowland wetland and riparian area within the Colorado Plateau region of western Colorado, eastern Utah, and southwestern Wyoming.
Category assessed
Avian richness.
Procedure
The user defines the area to be evaluated, visits the site, and completes field forms that (a) contain questions/indicators and (b) possible conditions for each indicator. After the applicable conditions are checked, the user inputs the information into AREM computer program and selects the applicable season(s) and subregion. The program will display the unweighted habitat score, the unweighted richness score, and weighted habitat scores for six weighting characteristics. Scores are provided for four cutoff levels. The program also provides options for changing the weighting factors, the species models, species in a subregion, and taxonomic placement of species.
Key Terminology
Cut-off level: threshold values (i.e., >0, >0.25, >0.50, >0.75) used to define which of the individual species habitat scores are included in the calculation of the AREM scores. For example, only species with a species habitat score >0.75 are used to calculate the unweighted habitat score reported in >0.75 cutoff column. The program tallies scores for each cutoff values. Users choose the cutoff that meets their needs.
Habitat index: product of an AREM score and site acreage.
Indicator: physical, chemical, and biological feature (or variable) of a habitat, at both site-specific and landscape scales, that can be estimated rapidly and that relate, either empirically or deterministically, to the habitat’s suitability for supporting individual species and/or avian diversity in general.
Species habitat score: a score from 0 (least suitable habitat) to 1 (most suitable habitat) for a species.
Unweighted habitat score: the species habitat score (on a scale representing habitat suitability of 0 to 1 for each species) summed across all species.
Unweighted richness score: the number of species predicted to occur.
Weighting characteristics: characteristics for which weights (scale 1-10) may be assigned to habitat scores, i.e., relative dependency on wetland/riparian habitat, relative abundance, taxonomic uniqueness, neotropical migrant status, official conservation designations, and hunted status.
Weighted habitat score: the product of each species’ species habitat score and a weighting coefficient, summed across all species. Weights are assigned to each species for each of six wetland characteristics .
Output
Measure of avian richness, habitat suitability, and species composition of a site.
Contact person
Paul Adamus, Adamus Resource Assessment, Inc., 6028 NW Burgundy Dr., Corvallis, OR 97330
phone: (503) 745-7092; fax: (503) 753-4507; e-mail: adamusp@ucs.orst.edu
Estimated time to assess 1 acre site
8 hours: Locate wetland (step 1)
2 hours per assessment area: Answer AREM questions (step 2), load AREM on computer,
and begin program (step 3).
Comparison of habitat types
Can directly compare all lowland wetland and riparian habitats within the Colorado Plateau.
Use as guide to design
AREM models may be used as a guide to design. Users can enter the computer program and examine the databases to determine which conditions increase or decrease habitat suitability. Habitat suitability for the marsh wren is considered minimally acceptable when the wetland has > 0.1 acre herbaceous, emergent vegetation (Data field Emin). If this condition is not met, the habitat is not considered suitable. Other variables provide information on conditions that should be avoided. For example, the wetland is less suitable when it is intensely grazed, mowed, or burned during nesting season (Data field GrazBurnMo). Finally, the information in the AREM models is useful because it provides design criteria with explicit measurements (e.g., 0.1 acre herbaceous, emergent vegetation).
Related procedures
None.
Extent of use/field testing
Initial testing was performed on 20 irrigated wetlands in Colorado to estimate AREM’s replicability, practicality, and comparability (Adamus 1993b). The accuracy of AREM was then determined by comparing field data with AREM predictions of species at 76 sites in the Colorado Plateau region during the breeding season (see Adamus 1995). AREM has been used to assess riparian restoration success and to determine mitigation requirements for wetland and riparian sites impacted by salinity control projects. The extent of use over the last two years is unknown.
Proposed future revisions
None.
KEY References
Adamus, P.R. 1993a. User’s Manual: Avian Richness Evaluation Method (AREM) for Lowland Wetlands of the Colorado Plateau. EPA/600/R-93/240. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR. 72 pp. NTIS # PB93186260.
Adamus, P.R. 1993b. Irrigated Wetlands of the Colorado Plateau: Information Synthesis and Habitat Evaluation Method. EPA/600/R-93/071. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR.
Adamus, P.R. 1995. Validating a habitat evaluation method for predicting avian richness. Wildlife Society Bulletin 23(4):743-749.