Assessment & Monitoring > Assessment Methods

Wetland Assessment Methods

CHNP has developed assessment and monitoring protocols for all three levels within the Level 1-2-3 Framework. All methods listed here have been developed with funding from U.S. Environmental Protection Agency Region 8 and Colorado Parks and Wildlife.

In addition to protocols developed by CNHP, additional wetland and riparian assessment protocols are used by various Colorado agencies and partners.

Level 1 Assessments (Top)

Digital National Wetland Inventory (NWI) mapping provides the most basic Level 1 assessment by quantifying the acres, types, and distribution of wetlands across a given landscape. This information is often the foundation of more intensive assessment, including serving as the sample frame needed to randomly select wetlands for the field-based Level 2 and 3 assessments.

For more information, see the Mapping page.

Landscape Integrity Model (LIM) for Wetlands is a statewide Level 1 GIS-based model of threats and stressors that affect wetland health. The model was built using specific anthropogenic stressors for which GIS layers are available. The impact of each stressor was weighted and scored based on best professional judgment (BPJ) of the stressor’s relative importance. Individual scores were then combined to create a cumulative, continuous surface of relative impact. High values equate to high stress and low landscape integrity while low scores equate to low stress and high landscape integrity.

From more information, see Section 2.2 of the report Wetland Strategies.

  • LIM

Level 2 Assessments (Top)

Ecological Integrity Assessment (EIA) framework forms the basis of CNHP’s Level 2 Rapid Assessment protocol. The EIA Framework was developed by NatureServe and ecologist from several Natural Heritage Programs across the country. Colorado-specific EIA protocols have been developed and refined by CNHP with funding from EPA Region 8 and Colorado Parks and Wildlife. The EIA method is an ecologically based condition assessment method that focuses on the biological response to disturbance, but also evaluates underlying processes.

EIA for Colorado Wetlands Field Manual

The EIA framework evaluates wetland condition using on a multi-metric index based on three major factors. Each factor has associated metrics, which are scored based on quantitative or qualitative criteria.

  • Landscape Context (landscape, buffer)
  • Condition (vegetation, hydrology, soil,   water quality)
  • Size

See the following links to download the field manual, datasheets, and presentations about applying the EIA method.

EIA for Colorado Wetlands Field Manual

EIA for Colorado Wetlands Datasheets (Level 2.5)

EIA for Colorado Wetlands Scorecard

EIA for Colorado Wetlands PowerPoint on Background and Guidance

Questions or comments about the EIA method can be directed to: Joanna Lemly.

Level 3 Assessments (Top)

Floristic Quality Assessment (FQA) is based on the concept of species conservatism. The core of the FQA method is the use of “coefficients of conservatism” (C-values), which are assigned to all native species in a flora. C-values range from 0 to 10 and represent an estimated probability that a plant is likely to occur in a landscape relatively unaltered from pre-European settlement conditions. High C-values are assigned to species which are obligate to high-quality natural areas and cannot tolerate habitat degradation, while low C-values are assigned to species with a wide tolerance to human disturbance. Generally, C-values of 0 are reserved for non-native species. C-values for Colorado species were assigned by a panel of botanical experts, as described in the report Floristic Quality Indices for Colorado Plant Communities.

C-Values Interpretation
0 Non-native species. Very prevalent in new ground or non-natural areas.
1-3 Commonly found in non-natural areas.
4-6 Equally found in natural and non-natural areas.
7-9 Obligate to natural areas but can sustain some habitat degradation.
10 Obligate to high quality natural areas (relatively unaltered from pre-European settlement).

The proportion of conservative plants in a plant community provides a powerful and relatively easy assessment of the integrity of both biotic and abiotic processes and is indicative of the ecological integrity of a site. The most basic FQA index is a simple average of C-values for a given site, generally called the Mean C, though more complex indices can be calculated. CNHP has developed a user friendly FQA Calculator to calculate FQA indices from any plant list.

Terminology, description and calculation of FQA indices (PDF)

Floristic Quality Assessment (FQA) Calculator

The FQA provides a unique approach to ecological monitoring and assessment that moves beyond simple measures of species richness and abundance and provides an estimate of the quality of native plants at a site. Under the assumption that plants effectively integrate spatial and temporal human impacts to ecological systems, FQA indices provide a cost-effective means of assessing ecological condition. FQA indices also provide consistent, quantitative measures of floristic integrity, can be used in any plant community, do not require extensive sampling equipment (only a competent botanist), and can be applied to existing data sets.

Vegetation Index of Biotic Integrity (VIBI). Biotic integrity is defined as the ability of an ecosystem to "support and maintain a balanced adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of natural habitats within a region." An index of biotic integrity (IBI) is a cost-effective and direct way to evaluate the biotic integrity of a wetland by measuring attributes of the biological community known to respond to human disturbance.

CNHP developed a vegetation index of biotic integrity (VIBI) for selected headwater wetland types within the Southern Rocky Mountains of Colorado: Subalpine-Montane Riparian Shrublands, Subalpine-Montane Fens, and Alpine-Montane Wet Meadows.

Colorado’s VIBI is a valuable tool that can be used by land managers to monitor and evaluate: (1) the performance of wetland restoration, enhancement, and creation projects; (2) the success of preserving ecological integrity via wetland protection projects; and (3) the effectiveness of on-going management practices.


Swink F. and G. Wilhelm. (1994) Plants of the Chicago Region. 4th Edition. Morton Arboretum, Lisle, IL.

Wilhelm, G. and D. Ladd. (1988) Natural area assessment in the Chicago region. Pp 361-375 in R.E. McCabe, editor, Transactions of the 53rd North American Wildlife and Natural Resources Conference. Wildlife Management Institute, Washington D.C.

Wilhelm, G. and L. Masters. (1996) Floristic Quality Assessment in the Chicago Region. The Morton Arboretum, Lisle, IL.

Non-CNHP Assessment Methods (Top)

Besides the methods developed by CNHP, there are two additional assessment methods that are widely used in Colorado.

Functional Assessment of Colorado Wetlands (FACWet) was developed by Dr. Brad Johnson with funding from the Colorado Department of Transportation. FACWet is a functionally based condition assessment method that focuses on physical drivers of wetland processes in an effort to highlight the causes of degradation. The FACWet method has been endorsed by the U.S. Army Corps of Engineers (ACOE) and is now required to accompany all Section 404 permits for wetland impacts or mitigation plans.

From a comparison of the EIA and FACWet methods, see Section 5.0 of the report Setting Mitigation in the Watershed Context (available soon).

Proper Functioning Condition (PFC) is an assessment process developed by the Bureau of Land Management to assess the physical functioning of riparian and wetland areas. The term PFC is used to describe both the assessment process, and a defined, on-the-ground condition of a riparian-wetland area.

See also: PFC (Proper Functioning Condition) What It Is and What It Isn't