Primary purpose
To predict potential habitat for individual species of wetland-dependent amphibians, reptiles, and mammals. Developed for New England state
agencies.
Expertise needed
Field technicians with a working knowledge of wetlands and trained in the use of WEThings collect and process data. Professional biologists review and interpret results.
Applicable habitat types
All wetland types in the New England area: Maine, New Hampshire, Vermont, Massachusetts, Connecticut, and Rhode Island. Also, possibly applicable to other states in the range of each species.
Categories assessed
Habitat potential for wetland-dependent amphibians, reptiles, and mammals.
Procedure
The user(s) generates a list of species that potentially use wetland habitats within the geographic area by referring to a table. During a site visit, the user(s) completes data forms that (a) characterize the overall wetland system (e.g., cover types and classification) and (b) contain 45 questions to be answered for each cover type. The field data is entered into the WEThings computer program to generate a potential species list for each cover type. The species list is reviewed or modified by referring to the individual models and applying best professional judgement. Individual species models may be applied without using a computer; more reliable predictions are generated in this manner.
Key Terminology
Features: habitat characteristics (e.g., wetland type, wetland vegetation, water depth) used in the habitat model to predict potential habitat for a species.
Habitat predicting model: descriptive ("word") models that use qualitative and quantitative (e.g., water depth) measures to identify potential habitat for each species.
Potential habitat: site that has the potential to provide habitat for a particular species, based on the habitat features.
Output
Prediction of habitat potential for each individual species within each cover type.
Estimated time to assess 1 acre site
Total 1-2 hours per covertype.
1-2 hours: Preliminary evaluation of species (step 1), field evaluation (step 2), and use WEThings computer program.
Comparison of habitat types
Can directly compare wetlands within the New England area.
Use as guide to design
WEThings reflects the state of published knowledge and some unpublished research, as of publication. WEThings’ authors expect that the accuracy is highest for species for which there is a well developed data base and least reliable for species for which few data exist. The authors do not represent WEThings as a design tool because of the highly variable species data set.
Some procedures are more suitable as a guide to design than others. While the authors of WEThings requested inclusion of the above cautionary note, I believe that compared to other procedures, WEThings provides useful design criteria that are largely based upon the literature. Most models are not supported by published/unpublished literature. We offer that, with knowledge of the above cautions, WEThings models may be used as a guide to design. Users can refer to the model variables (questions) to determine which conditions determine habitat potential. There is habitat potential for the red-spotted newt when the wetland is designed to have all of the listed characteristics. Characteristics that should be avoided are readily identified. For example, to be suitable for red-spotted newt eft, a non-palustrine forested should not be located greater than 150m away from a forested site (II. Juxtaposition). Finally, the information in the WEThings models is useful because it provides design criteria with explicit measurements (e.g., percent of average spring water depth 60-100 cm).
Contact person
Joseph Larson, Environmental Institute, University of Massachusetts, Amherst, MA 01003-0820 phone: (413) 545-2842; fax: (413) 545-2304; e-mail: larson@tei.umass.edu
Related procedures
WEThings Birds, a habitat predicting process that covers wetland dependent birds in New England, is in press (contact: Curt Griffin, Dept. of Foresty and Wildlife Mgmt., Univ. of Massachusetts).
Extent of use/field testing
Testing was limited to two species. There are no data on extent of use, but WEThings has reportedly been used on a variety of projects.
Proposed future revisions
WEThings and WEThings Birds are expected to be combined in a single computer program.
Key References
Whitlock, A.L., N.M. Jarman, J.A. Medina, and J.S. Larson. 1994a. WEThings: Wetland Habitat Indicators for Nongame Species. Volume I. TEI Publication 94-1. The Environmental Institute, University of Massachusetts, Amherst, MA. 45 pp.
Whitlock, A.L., N.M. Jarman, and J.S. Larson. 1994b. WEThings: Wetland Habitat Indicators for Nongame Species. Volume II. TEI Publication 94-2. The Environmental Institute, University of Massachusetts, Amherst, MA. 627 pp.