Wisconsin wetlands: assessment methods and tools
Assessment Intensity: Level 1, 2, or 3
The U.S. Environmental Protection Agency's National Wetlands Monitoring Workgroup has endorsed the concept of a Level 1, 2, 3 approach to monitoring wetlands. Level 1 covers the broadest geographic range with the least intensiveness and reliability (e.g., data collected using remote sensing and viewable using GIS), while Level 3 assessments are the most intensive and reliable but cover the smallest geographic area and require a greater investment in resources (e.g., floristic survey of a single wetland community). Level 2 assessments fall somewhere in between and include “rapid” assessments.
Level 1: Landscape Level Assessments
Level 1, or landscape-level assessments, rely on GIS applications and are based on data gathered using remote sensing. They are appropriate for gaining a rough estimate of wetland resources over a large area with minimal effort. Landscape level assessments are primarily recommended for planning purposes for users looking to assess larger landscapes or as preliminary data-gathering before more intensive surveys are completed. Because they are completed remotely and often based on modeled data or interpretation of aerial imagery, ground-truthing is always recommended to verify the accuracy of data collected using this method. An example of a Level 1 assessment tool used by DNR is the Wetlands By Design Decision Support Tool.
Level 2: Rapid Wetland Assessments
Level 2 "rapid" assessments, are on-the-ground evaluations of wetlands using tools designed to minimize time and effort in the field. These tools result in moderately detailed assessments that can stand alone or be used as screening tools to identify areas where more intensive assessments may be appropriate.
Three rapid tools are currently available for assessing overall wetland function and condition. The WI Wetland Rapid Assessment Methodology (WRAM), the Rapid Floristic Quality Tool, and Coarse-Level Metrics tools for Southern Sedge Meadow and Wet-mesic Prairie.
Level 3: Intensive Wetland Assessments
Level 3 "intensive site" assessments use research–derived, intensive measurements and produce the most reliable results. The Department has developed one Level 3 assessment protocol to assess wetland floristic quality, an indicator of wetland condition or health, the WI Floristic Quality Assessment Methodology. This protocol is recommended when an accurate assessment of wetland condition or a more detailed inventory of the plant resources is desired and requires a fair degree of botanical knowledge to complete.
What Aspects of Wetlands Can be Monitored and Assessed?
A wetland’s plant community type can say a lot about its ecological resources, functionality, and condition and is one of the simplest ways to monitor wetlands. Wetlands can be dynamic and can morph from one type to another in response to changes in hydrologic condition, land use, nutrient inputs, and various other physical, biological, or chemical shifts.
The Cowardin classification system categorizes wetlands coarsely according to dominant plant structure (i.e., forested, scrub-shrub, emergent, or aquatic). A wetland’s Cowardin type can be determined in the field or estimated using the DNR Wisconsin Wetlands Inventory.
To determine a wetland’s specific natural community type use the DNR Natural Heritage Inventory Program’s Key to Wetland Natural Communities of Wisconsin. Another community classification system often used by wetland regulators is the Eggers and Reed Wetland Plant Communities of Minnesota and Wisconsin.
Wetland Condition or Quality (Vegetation Surveys)
Wetland “condition” is synonymous with “quality” and describes how intact or free from anthropogenic alteration a wetland is. A wetland in excellent condition has an intact, fully functioning, healthy ecosystem while those in poor condition have been degraded and presumed to be functioning at a lower level.
Plants are commonly used to assess condition because they have proven to be excellent indicators of wetland stress and alteration averaged over long periods of time. Plants are also highly cost-effective to assess relative to other biological or physical measurements of condition such as macroinvertebrates or direct measurement of pollutants or soil alteration.
The DNR uses the Floristic Quality Assessment to assess wetland condition. The FQA evaluates condition using Coefficients of Conservatism, a rating of the relative sensitivity of individual plant species to disturbance.
DNR uses the following tools to measure wetland condition:
Level 2: DNR Rapid Floristic Quality Assessment (RFQA)
The RFQA uses the dominant plants in a wetland assessment area to calculate Rapid wC, a weighted plant conservatism metric. Rapid wC can be used to place a wetland in one of 4 broad conservatism groups, from Low to Exceptional. This method requires the assessor to be able to recognize fewer than 100 common wetland plants.
Level 2: Coarse-Level Monitoring Assessment (Southern Sedge Meadows and Wet-Mesic Prairies)
Coarse-level metrics provide an alternative means of rapid assessment. Each metric has established quantitative condition tiers ranging from best to lowest quality. Metrics can be rolled up to assess each parameter (composition, structure, and hydrology) separately as well as rolled up into a composite rank for the entire site. Evaluation of these metrics requires a basic understanding of wetlands but does not require extensive botanical expertise. Practitioners can use this method to evaluate initial site conditions, determine next management steps, and measure restoration progress over time. At this time, these have only been developed for southern sedge meadows and wet-mesic prairie wetlands.
Level 3: DNR Floristic Quality Assessment Methodology (FQA)
The FQA method consists of a full plant inventory of a wetland community completed using a timed-meander survey method. Plant species are converted to conservatism metrics and are used to place a wetland in one of 5 condition tiers, from Very Poor to Excellent, specific to a wetland’s community type and Level III Omernik Ecoregion. For more information on this method’s development and application see the Wetland Monitoring and Assessment Reports
- Timed-meander sampling protocol for wetland FQA
- This standard operating procedure describes how to complete a timed-meander survey to gather data to assess wetland floristic quality of condition.
- The WI FQA Calculator [XLSX]
- The FQA Calculator can be used to enter plant inventory data either during or after a timed-meander survey. Calculated metrics include species richness, non-native species cover, mean and cover-weighted conservatism and FQI. Guidelines and numeric criteria used to assign a condition category to a wetland are included. The calculator also includes the complete Wisconsin Vascular Flora in line with the Wisconsin State Herbarium with synonyms, Wetland Indicator Status, NR40 Status, NHI Protection Category, and accepted Integrated Taxonomic Information System (ITIS) name.
- Timed-meander sampling protocol for wetland FQA
WETLAND FUNCTION
Wetland functions include flood water storage and retention, hydrologic and groundwater functions, filtration and storage of nutrients and sediments, shoreline protection, habitat for wildlife, and recreational, cultural, educational, scientific, and natural scenic beauty benefits. To estimate wetland function more directly, DNR has Level 1 and Level 2 functional assessment tools:
Level 1: Wetlands by Design Decision Support Tool
The only available statewide wetland landscape assessment, Wetlands By Design, is a modeled version of a functional value assessment and restoration feasibility review of potentially restorable wetlands. This tool was created by The Nature Conservancy and the DNR to assist users in finding suitable sites for wetland protection and restoration.
- Wetlands by Design (select Wetlands and Watersheds Explorer)
Level 2: DNR WI Wetland Rapid Assessment Methodology (WRAM)
The WRAM is a standardized process for wetland professionals to evaluate the extent to which a specific wetland performs a given function. The full range of wetland functions and values are covered. This qualitative method incorporates the evaluator's best professional judgment and requires one or more field visits.
- WRAM data form
- WRAM user guide
This guide gives explanations for each of the questions asked in the WRAM data form and includes:- Appendix A – Wisconsin Priority Townships
- Appendix B – Wetland Characteristics for 12–Digit Watersheds
- Appendix C – Storm and Floodwater Storage Example
- Template for Storm and Floodwater Storage Calculation [XLS]
Note: DNR and Minnesota agencies are developing an updated version of the WRAM. See more information at MN BSWR. Public input will be requested in 2024.
