National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 

Freshwater Wetlands Monitoring and Assessment 

Framework for the Northeast Temperate Network 

Natural Resource Report NPS/NETN/NRR—2009/143 
ON THE COVER 

Freshwater marsh at Acadia National Park: 

Photograph by: Kevin Hop
Freshwater Wetlands Monitoring and Assessment 

Framework for the Northeast Temperate Network 

Natural Resource Report NPS/NETN/NRR—2009/143 

Don Faber-Langendoen 

NatureServe 

3467 Amber Road 

Syracuse, NY, 13215 

August 2009 

U.S. Department of the Interior 

National Park Service 

Natural Resource Program Center 

Fort Collins, Colorado
ii

The National Park Service, Natural Resource Program Center publishes a range of reports that address 

natural resource topics of interest and applicability to a broad audience in the National Park Service and 

others in natural resource management, including scientists, conservation and environmental 

constituencies, and the public. 

The Natural Resource Report Series is used to disseminate high-priority, current natural resource 

management information with managerial application. The series targets a general, diverse audience, 

and may contain NPS policy considerations or address sensitive issues of management applicability. 

All manuscripts in the series receive the appropriate level of peer review to ensure that the information 

is scientifically credible, technically accurate, appropriately written for the intended audience, and 

designed and published in a professional manner. This report received formal peer review by subjectmatter experts whose background and expertise put them on par technically and scientifically with the 

authors of the information. 

Views, statements, findings, conclusions, recommendations and data in this report are solely those of the 

author and do not necessarily reflect views and policies of the U.S. Department of the Interior, NPS. 

Mention of trade names or commercial products does not constitute endorsement or recommendation for 

use by the National Park Service. 

This report is available from the Northeast Temperate Network Inventory & Monitoring Program 

(http://science.nature.nps.gov/im/units/netn/) and the Natural Resource Publications Management 

website (http://www.nature.nps.gov/publications/NRPM). 

Please cite this publication as: 

Faber-Langendoen, D. 2009. A freshwater wetlands monitoring and assessment framework for the 

Northeast Temperate Network, National Park Service. Natural Resource Report NPS/NETN/NRR—

2009/143. National Park Service, Fort Collins, Colorado.

NPS 962/100253, August 2009
iii

Contents 

Page 

Figures..........................................................................................................................................................v 

Tables......................................................................................................................................................... vi 

Abstract..................................................................................................................................................... vii 

Acknowledgements.................................................................................................................................. viii 

Overview of Wetland Assessment and Monitoring.....................................................................................1 

Introduction............................................................................................................................................. 1 

A Conceptual Model for Wetlands ......................................................................................................... 2 

Ecological Integrity................................................................................................................................. 5 

Selection of Wetland Integrity Metrics................................................................................................... 5 

Rapid Field-Based Metrics ................................................................................................................. 5 

Intensive Metrics................................................................................................................................. 7 

Ecological Integrity Metrics and Reference Condition .......................................................................... 7 

Reference Condition ........................................................................................................................... 7 

Reference Condition and NETN......................................................................................................... 7 

Wetland Classification for NETN........................................................................................................... 9 

Ecological Systems and Formations ................................................................................................... 9 

Wetland Types in NETN Parks........................................................................................................... 9 

Field-Based Metrics for Assessing Wetland Ecological Integrity.............................................................15 

Overview of Rapid Metrics................................................................................................................... 15 

Stressor Checklist.................................................................................................................................. 31 

Overview of Intensive Metrics.............................................................................................................. 34 

Wetland Integrity Scorecard ......................................................................................................................35 

Introduction........................................................................................................................................... 35 

A Point-Based Approach ...................................................................................................................... 35 

Addressing Uncertainty when Assessing Metrics............................................................................. 36 

Role of Stressor Checklists ............................................................................................................... 36 

Weighting Metrics by Formation...................................................................................................... 36 

The Rapid Assessment Ecological Integrity Scorecard........................................................................ 36 

Landscape Context............................................................................................................................ 37 

Size.................................................................................................................................................... 37 

Vegetation (Biota)............................................................................................................................. 37 
iv

Hydrology ......................................................................................................................................... 38 

Soils (Physicochemistry) .................................................................................................................. 38 

Overall Index of Ecological Integrity (IEI) Rank............................................................................. 39 

The Intensive Assessment Ecological Integrity Scorecard................................................................... 39 

Adapting the Methods Over Time ........................................................................................................ 39 

Sampling Design and Field Methods.........................................................................................................41 

Sampling Design................................................................................................................................... 41 

Overview of Sampling Methods ........................................................................................................... 41 

Some Guidelines for Field Methods ..................................................................................................... 42 

References..................................................................................................................................................45 

Rapid Field Metric Descriptions................................................................................................................49 

Appendix A. Field Form Requirements.....................................................................................................51 

Appendix B. Template for Metric Description..........................................................................................53 

Appendix C. Draft Set of Intensive Metrics for NETN Wetlands.............................................................55 

Appendix D. Vegetation Field Sampling...................................................................................................65 
v

Figures 

Page 

Figure 1. General conceptual diagram showing the major ecological attributes of wetland integrity: 

hydrology, soils , vegetation (summarized as “condition”), and the influence of wetland size and 

landscape context. The surrounding geomorphic landscape and climate exert controls over these 

attributes.......................................................................................................................................................3 

Figure 2. Detailed conceptual model for wetland systems in the Northeast Temperate Network, 

showing the relation of drivers and stressors to the five major ecological attributes of wetlands – 

landscape context, size, hydrology, physicochemistry, and biota. ..............................................................4
vi

Tables 

 Page 

Table 1. Approximate extent (hectares) of NatureServe freshwater wetland ecological systems 

present within NETN parks. This information will be updated and improved after completion of the 

Inventory & Monitoring mapping inventory of these parks. Area listed in larger boxes spanning 

more than one ecological type indicates that current information does not distinguish between related 

types. Adapted from Mitchell et al. (2006). ................................................................................................................ 10

Table 2. Overview of rapid field-based (Level 2) metrics for assessing wetland integrity. .....................17

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity. ..19

Table 4. Instructions for using the Stressors Checklists (the following guidance is under review, and 

is adapted from Master et al. (2009)).........................................................................................................31

Table 5. Stressor Checklist Worksheets for Assessment Area (site). Checklist adapted from Collins 

et al. (2006). ...............................................................................................................................................33

Table 6. Overview of a draft set of intensive field based metrics for assessing freshwater wetland 

integrity. Metric Type: C = condition based metric, and S = stressor metric...........................................34

Table 7. Landscape Context rating calculation for wetlands in the Northeast Temperate Network.........37

Table 8. Size rating* calculation for wetlands in the Northeast Temperate Network. .............................37

Table 9. Vegetation (Biota) rating* calculation for wetlands in the Northeast Temperate Network. ......38

Table 10. Hydrology rating* calculation for wetlands in the Northeast Temperate Network..................38

Table 11. Soils (Physicochemistry) rating* calculation for wetlands in the Northeast Temperate 

Network......................................................................................................................................................39

Table 12. Overall IEI rank* calculation for wetlands in the Northeast Temperate Network. ..................40

Table 13. Example of scores and ranks for metrics, factors, and the overall ecological integrity for a 

Level 2 Rapid Field-based Assessment. ....................................................................................................40
vii

Abstract 

The Northeast Temperate Network (NETN) of the National Park Service is developing a freshwater 

wetland monitoring program as part of the overall development of its vital signs monitoring program. 

This report presents a prototype of a rapid assessment method based on an ecological integrity 

assessment perspective that is compared with a prototype intensive assessment method. 

The major components of the rapid assessment proposed include 1) using a standardized classification of 

wetland types, 2) identifying key ecological attributes and indicators for each wetland type that reflect 

composition, structure and function, 3) identifying practical metrics with ratings and thresholds based on 

“normal” or “natural” benchmarks; and 4) providing a reporting scorecard by which the 

indicators/metrics are rated and integrated into an overall wetland index of ecological integrity (IEI). 

We compiled a list of 15 indicators/metrics of condition for freshwater wetlands that cover the five 

major attributes of our wetland conceptual model: landscape context, size, biota, hydrology, and 

soils/physicochemistry. Each metric is described in full, and protocols are provided for its consistent 

measurement in the field. Guidance on assessing stressors is also provided. We compared the set of 

rapid metrics to a possible set of intensive wetland metrics. 

We developed an index of ecological integrity from these metrics using a scorecard format. The table is 

structured so that the score for each metric and major attribute is provided along with the overall index. 

The report is concluded by noting the need for a sampling design and briefly discussing a set of field 

protocols, topics that extend beyond the scope of this report. 
viii

Acknowledgements 

I am grateful for financial assistance from the National Park Service to develop this freshwater wetland 

assessment method for the Northeast Temperate Network (NETN) of parks. Brian Mitchell provided 

valuable coordination and advice throughout the project, including peer review of this report. Geri 

Tierney provided much input on the initial conceptual modeling that was part of the overall NETN Vital 

Signs monitoring program (Mitchell et al. 2006). 

The design of this wetland assessment and monitoring scorecard is based on an extensive effort by 

NatureServe and the Natural Heritage Network to improve that core methodology by using an ecological 

integrity framework. These improvements draw on the experience and collaboration with partners, 

including The Nature Conservancy, and with federal partners, particularly the Environmental Protection 

Agency (EPA), which provided funds to NatureServe to work on ecological integrity assessments for all 

wetland types in the U.S. Other support comes from the National Park Service, the Army Corps of 

Engineers, and the U.S. Forest Service. 

This report draws on the extensive collaboration with colleagues from NatureServe and the Natural 

Heritage Network. I especially thank Greg Kudray, Carl Nordman, Lesley Sneddon, Linda Vance, Sue 

Gawler, Carmen Josse, Gwen Kittel, Shannon Menard, Elizabeth Byers, Pat Comer, Esteban Muldavin, 

Joe Rocchio, and Mike Schafale for their input during the development of a rapid wetland assessment 

for the EPA project. I also thank two anonymous reviewers and Hilary Neckles for their helpful 

comments on this report. 

The analysis and conclusions documented in this publication are those of NatureServe and may not 

necessarily reflect the views of the National Park Service. 
1

Overview of Wetland Assessment and Monitoring 

Introduction 

The Northeast Temperate Network (NETN) of the National Park Service is developing a freshwater 

wetland monitoring program as part of the overall development of its vital signs monitoring program 

(Mitchell et al. 2006). Two approaches are being considered. First, an intensive field-based monitoring 

program is being developed, currently applicable to wet meadows and alkaline fens (Neckles et al. 

2007). Second, a rapid field method is being developed for all wetlands. The two methods will be 

designed to complement each other. Here we present the rapid assessment method. 

Wetland assessments, whether intensive or rapid, are increasingly using an indicators-based approach to 

assessing and reporting on ecological condition (Harwell et al. 1999, Young and Sanzone 2002, U.S. 

EPA 2002). Assessing the current ecological condition or integrity of an ecosystem requires developing 

measures of the structure, composition, and function of an ecosystem, as compared to reference or 

benchmark ecosystems operating within the bounds of natural or historic disturbance regimes 

(Lindenmayer and Franklin 2002, Young and Sanzone 2002). However, selection and development of 

indicators can be challenging, given the diversity of organisms and systems, the large number of 

ecological attributes that could be measured, and concerns over cost effectiveness and statistical rigor. 

Indicators of meaningful change can be developed in multiple ways. There is increasing recognition that 

some change can be detected using remote sensing information, other changes using rapid assessments, 

and others only by detailed, intensive assessments. Together these form what has been called a 3-level 

approach to wetland monitoring and assessment (Brooks et al. 2004, Tiner 2004, USEPA 2006). 

Working at multiple levels can give managers more flexibility for assessing changes in ecological 

integrity. It also requires a greater variety of tools to identify the metrics at each level. For example, for 

intensive metrics statistical screening tools can be used (Barbour et al. 1996, Blocksom et al. 2002). For 

rapid metrics, which are more semi-quantitative to qualitative, a combination of graphical and simple 

categorical tools can be used (Karr and Chu 1999, Mack 2001). 

Ideally, information at the three levels of assessment will also provide relatively consistent information 

about ecological integrity, with improved interpretations as the level of intensity increases. To achieve 

this, the various levels need to be calibrated against one another. Where rapid assessment metrics have a 

corresponding intensive metric, the rapid metric can be calibrated against the intensive metric. For 

example, a rapid vegetation metric may require that the overall percent-cover of native species versus 

exotic species be compared, whereas an intensive metric may be based on a Floristic Quality Index or 

Vegetation Index of Biotic Integrity that scores each species or group of species based on sensitivity to 

human stressors. By measuring both metrics in the same wetland, the thresholds for the rapid metrics 

can be calibrated against those of the intensive metric. 

To ensure that the 3-level approach is consistent among levels, various studies have recommend using a 

standard framework or model for choosing metrics (e.g., Harwell et al. 1999, Young and Sanzone 2002, 

Parrish et al. 2003, Faber-Langendoen et al. 2006). The framework identifies a common set of key 

ecological attributes and categories (such as landscape context, size hydrology, soils and biota) for all 

three levels. Choosing metrics or indicators within this framework ensures that a comparable set of 

wetland characteristics are being assessed. This guiding framework can be used to evaluate and integrate 

the growing list of wetland metrics and indices that are being developed for use in wetland condition 

assessments, including by many states (see review by Fennessy et al. 2004, 2007). 
2

The NETN program has already made substantial progress on creating an intensive (level 3) field-based 

monitoring program for upland forests (Tierney et al. 2009), though some rapid level 2 metrics are 

included. The protocol uses an indicators or metrics-based approach, and provides a scorecard that 

presents ratings at the level of each metric. That program is commencing its third year of sampling. A 

landscape (level 1) set of metrics for forests will be developed based on guidance from the national Vital 

Signs landscape program. 

Wetlands, although less common on the park landscapes, are in some ways more complex and diverse 

than forests in terms of their structure, composition, and dynamics. There are a greater variety of 

intensive metrics that might be needed to cover all wetland types, and measuring them all could be cost 

prohibitive. In order to initiate the process of selecting metrics and assessing wetlands, we first 

developed a rapid field-based (level 2) monitoring and assessment program for NETN wetlands, 

intended to complement an intensive field based assessment developed by Neckles et al. (2007), 

including alkaline fens and wet meadows. As with forests, a landscape (level 1) set of metrics for 

wetlands will be developed from guidance provided by the national Vital Signs landscape program. 

The major components of the rapid assessment being proposed include (1) using a standardized 

classification of wetland types, (2) identifying key ecological attributes and indicators for each wetland 

type that reflect composition, structure and function (pattern and process), with protocols for measuring 

those indicators to ensure consistent field measurements and documentation, (3) identifying practical 

metrics with ratings and thresholds based on “normal’ or “natural” benchmarks; and (4) providing a 

reporting scorecard by which the indicators/metrics are rated and integrated into an overall wetland 

index of ecological integrity (IEI). 

Our rapid assessment methods are a prototype intended for further testing and refinement. They should 

be validated through comparisons with a reference set of wetland sites in the NETN region. They should 

also be calibrated through cooperative intensive studies, where both rapid and intensive metrics are 

measured at the same site. 

A Conceptual Model for Wetlands 

Wetlands can be defined based on hydrology, soils and physicochemistry, and biota (Mitsch and 

Gosselink 2000). These three components form the basis for the development and functioning of 

wetland ecosystems (Figure 1). Water is present in all wetlands at one time or another but the depth and 

duration of flooding (i.e., hydrology), varies substantially among wetland types. Hydrology is the 

defining physical parameter that separates wetland ecosystems from terrestrial and deep water aquatic 

systems. Hydrology is thus a most important factor in the establishment and maintenance of 

characteristic types of wetlands and wetland processes. In turn, the starting point for the hydrology of a 

wetland is the climate and basin geomorphology (Mitsch and Gosselink 2000). The diverse climatic, 

hydrologic, and geomorphologic settings of wetlands influence the physicochemical environment of the 

wetland, which is defined as the soils, chemical properties, and processes that interact with the 

hydrology to influence the biota. The physicochemical environment also includes the cycling of and 

transformation of biochemicals through the wetland. Soils are both the medium in which many of these 

transformations occur and the source (i.e., storage) of available chemicals for plants. In turn, wetland 

biota both respond to and control, through feedback loops, the hydrology and biogeochemistry of 

wetlands (e.g., coarse woody debris, beavers, muskrats, geese) (Mitsch and Gosselink 2000). 
3

Figure 1. General conceptual diagram showing the major ecological attributes of wetland integrity: hydrology, 

soils , vegetation (summarized as “condition”), and the influence of wetland size and landscape context. The 

surrounding geomorphic landscape and climate exert controls over these attributes. 

Many of these processes are strongly influenced by coupling with adjacent ecosystems, which form the 

landscape context of the wetland. “Open” wetlands (i.e., riverine, lacustrine, or coastal) regularly 

exchange water, chemicals, and biota with adjacent systems. In contrast, “closed” systems, such as bogs, 

have little material exchange. All wetland types are affected to varying degrees by alterations to adjacent 

ecosystems. 

A fifth attribute, wetland size, is closely related to landscape context. Size is an important attribute 

because it limits the abundance of area-dependent species and influences the level of heterogeneity and 

diversity of wetland composition. There is an interaction between size and landscape context. With 

increasing size, wetlands are more likely to be buffered from adjacent stressors. A small wetland in a 

large, natural, landscape may retain many important aspects otherwise found in large wetlands, whereas 

that same wetland would not in a fragmented landscape. 

Thus, a full set of core major ecological attributes of wetland ecosystems include hydrology, 

soils/physicochemistry, vegetation, size, and landscape context. The first three attributes can be 

combined into an overall “condition” factor, to form a triad of landscape context, size, and condition 

factors (Fig. 1 and Faber-Langendoen et al. 2008b). This general conceptual model can be refined into a 

more specific model using figures and a narrative that describes the current understanding of wetland 

system attributes and their interactions (Figure 2). A detailed narrative of the model is provided in 

Mitchell et al. (2006). The specific model includes the effects of drivers and stressors that affect the 

major attributes. Additional attributes, such as focal taxa (birds, mammals, amphibians, rare plants) are 

difficult to monitor as part of a rapid assessment at a site level, but can be monitored selectively. Their 

data can then be linked to the results of the core assessments. 
4

Figure 2. Detailed conceptual model for wetland systems in the Northeast Temperate Network, showing the 

relation of drivers and stressors to the five major ecological attributes of wetlands – landscape context, size, 

hydrology, physicochemistry, and biota. 

NATURAL DISTURBANCE REGIME

Storm, fire, drought, flood CLIMATE

VEGETATION

FOCAL TAXA

amphibians, reptiles, breeding birds

HYDROLOGY

BEAVER

ENGINEERING

ATMOSPHERIC

DEPOSITION

INVASIVE EXOTIC

SPECIES

CLIMATE

CHANGE

CONTAMINATION

DEER HERBIVORY

HYDROLOGIC

ALTERATION

LAND MANAGEMENT/

AGRICULTURE

LANDSCAPE CONTEXT

 land cover, buffer

ECOLOGICAL PROCESSES

EROSION/ Nutrient cycling, productivity

SEDIMENTATION

WATERSHED / 

GEOMORPHOLOGY

Stressor

Driver

KEY: Comp, structure

Focal 

Resources

Process

NUTRIENT

ENRICHMENT ROADS

NEARBY LANDUSE

SOIL

 (physicochemistry)

SIZE
5

Ecological Integrity 

Ecological integrity can be defined as “an assessment of the structure, composition, and function of an 

ecosystem as compared to reference ecosystems operating within the bounds of natural or historic 

disturbance regimes” (adapted from Lindenmayer and Franklin 2002 and others). The concept of 

“ecological integrity” provides a useful framework for selecting monitoring variables and assessing 

progress towards ecologically-based management goals (Harwell et al. 1999). The notion of naturalness 

depends on an understanding of how the presence and impact of human activity relates to natural 

ecological patterns and processes (Kapos et al. 2002). Identification of reference or benchmark 

conditions based on natural or historic ranges of variation, although challenging, can provide a basis for 

interpretation of natural and historic ranges of variation (Swetnam et al. 1999). 

Several approaches can be taken to assess wetland integrity (Kapos et al. 2002). First, indicators can be 

used to assess key aspects of wetland structure, composition and/or function. This strategy has the 

advantage of directly addressing the primary concern, which is the state of the ecosystem. Identification 

of a suite of reference or benchmark sites is an important component of such an approach to avoid some 

of the difficulties concerning effects of human-induced changes in ecosystems (Brooks et al. 2004, 

Stoddard et al. 2006). Second, the stressors (negative human impacts) and ecological drivers (climate, 

geology, natural disturbances) can be assessed separately from the responses—ecological integrity and 

change. Separation of the drivers and stressors (causes) and responses (ecological effects) provides a 

valuable analytical tool (Kapos et al. 2002, Tierney et al. 2009). 

Selection of Wetland Integrity Metrics 

Rapid Field-Based Metrics 

The metrics presented here are part of a national effort to select metrics for rapid assessment and 

monitoring of ecological integrity of wetlands. A core ecology team of NatureServe and Natural 

Heritage Network staff have reviewed the literature on wetland assessments. This review helped us 

reach agreement on the models that were presented above, including the decision to work with the major 

attributes identified in the conceptual models—landscape context, size, biota, hydrology, and 

soils/physicochemistry (see Fennessy et al. 2004, 2007). 

We then reviewed a variety of existing rapid wetland assessment and monitoring materials, particularly 

that of the California Rapid Assessment Manual (CRAM, Collins et al. 2006, 2007), the Ohio Rapid 

Assessment Manual (Mack 2001), as well as a variety of others from North Carolina, Montana, and 

Delaware. We also consulted a variety of Hydrogeomorphic assessment manuals. Some of these 

materials have already been summarized in previous work by NatureServe (Faber-Langendoen et al. 

2006). From the list of metrics provided by those assessments, we attempted to narrow down the list of 

metrics using the following criteria (Andreasen et al. 2001, Kapos et al. 2002, Faber-Langendoen et al. 

2006): 

 Useful at multiple spatial scales 

 Inclusive across ecological attributes of composition, structure and function 

 Grounded in natural history and ecologically relevant 

 Practically relevant to managers, decision-makers, and the public—not just scientists 

 Flexible 

 Feasible to implement and measure, with relevant target or threshold settings 

 Responsive, including to changes from stressors 
6

Multiple Spatial Scales: We identify metrics that address issues of the individual plot or assessment 

area, the full wetland patch, and the surrounding landscape. In this way, ecological factors that vary in 

their spatial characteristics can be tracked. 

Inclusive of a Range of Ecological Attributes: We work with an ecosystem model of wetlands that 

includes the major attributes of vegetation, soils, hydrology, size, and landscape context. We review 

metrics that address these major attributes. 

Natural History and Ecological Relevance: Our overall concern is to measure ecological integrity or 

condition; that is, the overall naturalness/normalcy of ecological patterns and processes operating in a 

wetland. We have ensured that the metrics are broadly applicable, both geographically and for as wide a 

set of freshwater wetlands as possible. We have ensured the ecological relevance of the metrics by 

evaluating them by the major ecological attributes (Figure 2). In addition, we have looked for linkages 

between metrics. For example, landscape context metrics, such as buffer, provide information on 

changes to the surrounding landscape that will also affect metrics that are directly assessing hydrological 

and biotic changes within a wetland. 

 

Practical Relevance: We have also sought to make any thresholds relative to determining quantitative or 

qualitative thresholds for condition as meaningful for managers as possible; that is, changes in a metric 

should be helpful to making management decisions. Thus, in so far as ecological integrity or condition is 

part of management goals, the metrics will be significant. But further input is needed to be sure that 

specific management goals for NETN have not been omitted. 

Flexibility: Metrics need to be available to answer questions with varying degrees of resolution, 

depending on manager’s needs and shifting priorities, and available funding, 

Feasibility: We sought to ensure feasibility in several ways. First, we chose, wherever possible, to rely 

on metrics already tested and in use by various state wetland programs. Second, several members of the 

NatureServe team are actively testing these metrics (e.g., Rocchio 2007). Third, we relied on our own 

professional judgment, based on experiences with similar kinds of field assessments in other projects. 

Thus, we are confident that these metrics are well-documented, rapid, cost-effective, often have baseline 

data available from other projects outside of NETN, easily measured with little equipment or specialized 

knowledge, and have a large sampling window (i.e., can be sampled throughout much of the growing 

season). 

Responsivity: Because rapid metrics rely on a combination of qualitative and quantitative metrics, they 

can be more challenging to apply consistently than strictly quantitative metrics, which can introduce 

some measurement error or lack of repeatability. We sought to minimize these issues by ensuring that, 

for each of the four major attributes, at least some metrics were simple quantifiable ones. For the more 

qualitative metrics, an expansive narrative was provided for guidance. We are less concerned about 

statistical power in rapid assessments, and more concerned with a qualitative discrimination of wetland 

integrity that is open to validation through quantitative assessments. In some ways, the qualitative 

metrics are better able to control for temporal and spatial variability, because they often ask the field 

observer to integrate a variety of observations. For example, when assessing soil disturbance, the metric 

relies on visual evidence of trampling, including ATV or ORV tracks and trails that are readily observed 

and persistent throughout the season. 
7

Intensive Metrics 

At this time, the development of intensive metrics for NETN wetlands is still preliminary, based in part 

on the work of Neckles et al. (2007) for wet meadows and alkaline fens. There are other studies 

developing intensive metrics for a variety of wetlands (e.g., Miller et al. 2006a, b). Intensive metrics 

should be far more accurate and informative about wetland patterns and processes than Level 2 metrics, 

but they may only be measurable in a select set of wetlands, whereas Level 2 metrics could be measured 

across a wider set of wetlands. Ensuring that the two levels of metrics are coordinated should allow for 

greater interpretive value of both (Mack 2006). 

Ecological Integrity Metrics and Reference Condition 

Reference Condition 

In selecting and establishing metrics for assessing ecological integrity, an assumption is made that some 

type of reference condition can be defined; that is, it is possible to describe a series of states of wetland 

integrity, from minimally disturbed to degraded (Faber-Langendoen et al. 2008a). Optimal conditions 

are typically defined with respect to an acceptable or natural range of variation (or historic range of 

variation). For many elements, what is natural or historical is difficult to define, given the vagaries of 

those concepts and the relative extent of human disturbance over time. For example, in an 

undocumented past, people may have used fire to clear patches of forest over several millennia, altering 

land/waterscapes and influencing species distributions. However, through careful scientific study, 

reflections on historical data, and comparisons with the best-preserved occurrences, we can often 

distinguish effects of intensive human uses and begin to describe a natural range of variation for 

ecological attributes that maintain the occurrence over the long-term (Swetnam et al. 1999). It is this 

practical concept that we apply to evaluating wetland integrity. 

Reference wetlands (or the reference set) are the wetland sites selected to represent the range of 

variability that occurs in a wetland type as a result of natural processes and disturbances (e.g., 

succession, channel migration, fire, erosion, and sedimentation), and anthropogenic alteration (e.g., 

grazing, timber harvest, and clearing) (Klimas et al. 2006). Reference wetlands serve several purposes. 

First, they establish a basis for defining what constitutes a characteristic and sustainable level of 

integrity across the suite of attributes selected for a type. Second, reference wetlands establish the range 

and variability of conditions exhibited by assessment variables, providing data necessary for calibrating 

assessment variables and models. Finally, they provide a concrete physical representation of wetland 

ecosystems that can be observed and re-measured as needed (Smith et al. 1995, Klimas et al. 2006). 

Reference standard wetlands are the subset of reference wetlands that exhibit metric ratings for the type 

at a level that is characteristic of the least altered (or minimally disturbed) wetland sites in the least 

altered landscapes (Klimas et al. 2006, Stoddard et al. 2006). These reference standards would typically 

have “A” (excellent) ratings for individual metrics and categories. To complete the full reference set, B, 

C and D rated sites are also identified and rated as variously degraded versions of A-ranked reference 

standards. 

In establishing reference standards, the geographic area from which reference wetlands are selected is 

sometimes referred to as the reference domain (Smith et al. 1995). The reference domain may include all 

(ideally), or part of the geographic area in which a type occurs. 

Reference Condition and NETN 

Much work has already been done throughout the Northeast to locate hundreds of exemplary (‘A’ or ‘B’ 

ranked) wetland sites on both managed and protected lands (Anderson et al. 2006). But assessments of 
8

these sites need to be validated. By using a series of known reference sites across a range of 

management activities, and with partners who have already begun to implement some aspects of 

ecological integrity assessments, we fully expect that a series of wetland sites of the same types found at 

NETN can be visited and measured using the set of ecological metrics below. To be an effective 

network of reference wetlands we suggest the following steps: 

1) Engage the Partners: Form an advisory team among partners that are already working on 

measuring various aspects of ecological integrity and wetland condition to identify shared goals, 

common sampling designs, and compatible reporting structures. 

2) Identify a Suite of Reference Sites: Extensive work has already been done in the region to 

identify the highest quality landscape-scale sites across the region, including work by The Nature 

Conservancy to identify its priority ‘matrix blocks’. Within these landscape scale sites, many 

‘benchmark’ or reference wetland sites exist, such as those found within the Maine Ecological 

Reserves and known wetland sites in the Adirondacks and Catskills. A set of sites could be 

identified that cover the ecological variation across the region, as well as adjacent sites where 

stressor levels are higher and management history differs. A screening process should be 

developed that assesses independent abiotic (e.g., landscape stressor models based on land use 

and other human disturbance factors) and biotic stressors on these sites. Measures of ecological 

integrity can then be assessed and compared to these stressores. 

3) Review and Analyze Quantitative Data: Large amounts of data has already been gathered at 

many wetland sites. An effort should be made to compile and collect data on wetland structure 

and composition from a variety of sources, prioritizing the collection of data at three scales—

site, large landscape, and region-wide. Provided compatible data can be found across a range of 

sites, comparison across the full range of ‘A’ to ‘D’ conditions could be developed. In addition, 

where sites exist that have data comparable to level 3 metrics (e.g., detailed species composition 

or hydrology information), sites could be visited and sampled using level 2 metrics. 

4) Develop and Refine Attributes, Metrics, and Thresholds: The reference data sets can be used to 

calibrate the specific ranking attributes, metrics, and thresholds for poor, fair, good, and excellent 

wetland conditions, using both level 2 and level 3 metrics. Where data are sufficient to test the 

statistical significance of the metrics, they could be analyzed to gauge variability among 

measures of each indicator metric, document redundancy among selected metric ratings, and 

recommend a minimum set of metrics for effective assessment of forest integrity at multiple 

scales. Statistical screening tools, such as those outlined by Blocksom et al. (2002), can be used 

to test the discriminatory power between minimally disturbed and degraded conditions. In 

addition, the rapid assessment metrics can be calibrated against the intensive metrics. 

Although the establishment of a series of reference sites per se outside of the National Park System is 

beyond the mandate of NETN, it is feasible through a partnership with other organizations and agencies 

interested in documenting wetland reference conditions (e.g., Brooks et al. 2004, Faber-Langendoen et 

al. 2008b). It may be similar to the regional network of sites that have been developed for assessing salt 

marsh restoration (Konisky et al. 2006). Such a study will also permit a greater refinement of the 

qualitative narratives used for some of the metrics proposed here. 
9

Wetland Classification for NETN 

Ecological Systems and Formations 

We have been discussing general issues in selecting ecological metrics for wetlands. But the success of 

developing indicators of wetland ecological integrity depends on an understanding of the structure, 

composition, and processes that differ across the wide variety of wetland systems. Ecological 

classifications can be helpful tools in categorizing this variety. These classifications help wetland 

managers to better cope with natural variability within and among types, so that differences between 

occurrences with good integrity and poor integrity can be more clearly recognized. Here we rely on two 

major classifications approaches: Ecological Systems (Comer et al. 2003) and the U.S. National 

Vegetation Classification (USNVC) (FGDC 2008, Faber-Langendoen et al. 2009). 

Our primary classification, also used by NETN for forest monitoring, is NatureServe’s Ecological 

Systems (Comer et al. 2003). Ecological Systems provide a spatial-ecologic perspective on the relation 

of associations and alliances (fine-scale plant community types), much as soil associations help portray 

the spatial-ecologic relations among soil series in a soil taxonomic hierarchy. Systems types facilitate 

mapping at meso-scales (1:24,000 - 1:100,000). 

Our secondary classification is the USNVC, which is the primary classification used for mapping the 

vegetation of the national parks, including all wetlands (e.g., for Acadia National Park, see Lubinski et 

al. 2003). The USNVC is a conceptual/taxonomic hierarchy of vegetation, ranging from broad-scale 

formations to fine-scale alliances and associations. It provides an organizing framework for Ecological 

Systems, using the NVC formation level (see Table 1). 

Currently two other major classifications are widely used for wetlands work, the National Wetlands 

Inventory (NWI), as summarized in Cowardin et al. (1979), and the Hydrogeomorphic (HGM) 

classification (Brinson 1993). A comparison of these classifications with the USNVC and Ecological 

Systems is provided in Faber-Langendoen et al. (2008a). The Systems and USNVC Formation types 

share with the HGM approach the use of hydrogeomorphic criteria, but the first two approaches also use 

biota, soils, climate and other criteria to define types. An important benefit of using the USNVC and 

Ecological Systems classifications for NETN monitoring is that they are comprehensive for all 

ecosystems, not just wetlands. They provide a framework for all ecological integrity or condition 

assessments, and also a comprehensive classification and mapping approach for park landscapes. 

Wetland Types in NETN Parks 

Freshwater wetlands are present in all NETN parks (Table 1). Acadia (ACAD), the largest park in the 

Northeast Temperate Network, contains 2,233 acres (904 ha) of wetlands, followed by Minute Man 

(MIMA) with 261 acres (106 ha), and Saratoga (SARA) with 91 acres (37 ha). All other parks contain 

less than 37 acres (15 ha) of wetlands. Salt marsh wetlands are found at ACAD and Boston Harbor 

Islands (BOHA), but are not included in Table 1. 
10 

Table 1. Approximate extent (hectares) of NatureServe freshwater wetland ecological systems present within NETN parksupdated and improved after completion of the Inventory & Monitoring mapping inventory of these parks. Area listed in large

than one ecological type indicates that current information does not distinguish between related types. Adapted from Mitch

USNVC Formation NatureServe Ecological System Type Northeast Temperate Network Par

ACAD BOHA MABI MIMA MORR ROVA SAGA 

Floodplain & Swamp Forest Laurentian-Acadian Floodplain Forest - - - 4 - - - 

Central Appalachian Floodplain - - - - - - - Eastern Boreal Semi-Treed Bog/Acidic Swamp 146 - - - - - - Laurentian-Acadian Acidic Swamp 214 - 4 58 - - - 

North Central Appalachian Acidic Swamp - - - - 6 9 - 

Bog & Fen Acadian Maritime Bog 37 - - - - - - 

Laurentian-Acadian Acidic Basin Fen 216 - - 2 - - - 

Laurentian-Acadian Alkaline Fen 68 - - - - - - 

Freshwater Marsh Laurentian-Acadian Wet Meadow-Shrub Swamp & Marsh 223 12 0.2 42 9 3 5 
11

Freshwater wetlands in NETN parks are comprised of nine different types of wetland ecological systems 

(NatureServe 2003) and vernal pools. These types are summarized below (from Mitchell et al. 2006):

Temperate Floodplain & Swamp Forest 

Laurentian-Acadian Floodplain Forest: These systems encompass north-temperate floodplains in the 

northeastern and north-central U.S. and adjacent parts of Canada at the northern end of the range of 

silver maple. They occur along medium to large rivers where topography and process have resulted in 

the development of a complex of upland and wetland temperate alluvial vegetation on generally flat 

topography. This complex includes floodplain forests, with silver maple (Acer saccharinum) 

characteristic, as well as herbaceous sloughs and shrub wetlands. Most areas are underwater in spring, 

with microtopography determining how long the various habitats are inundated. Associated trees include 

red maple (Acer rubrum) and American hornbeam (Carpinus caroliniana), the latter frequent but never 

abundant. On terraces or in more calcareous areas, sugar maple (Acer saccharum) or red oak (Quercus 

rubra) may be locally prominent, with yellow birch (Betula alleghaniensis) and ash (Fraxinus spp.). 

Black willow (Salix nigra) is characteristic of the levees adjacent to the channel. Common shrubs 

include silky dogwood (Cornus amomum) and viburnum (Viburnum spp). The herb layer in the forested 

portions often features abundant spring ephemerals, giving way to a fern-dominated understory in many 

areas by mid-summer. Non-forested wetlands associated with these systems include shrub-dominated 

and graminoid-herbaceous vegetation. 

Central Appalachian Floodplain Forest: These systems encompass floodplains from New England to 

Virginia. Mostly forested, these occur on floodplains of medium to large rivers where topography and 

process have resulted in the development of a relatively flat floodplain with a complex of upland and 

wetland temperate alluvial vegetation. This complex includes floodplain forests in which silver maple, 

Eastern cottonwood (Populus deltoids), and American sycamore (Platanus occidentalis) are 

characteristic, as well as herbaceous sloughs and shrub wetlands. Most areas are underwater in spring 

with microtopography determining how long the various habitats are inundated. Depositional and 

erosional features may both be present depending on the particular floodplain, although there is a history 

of deposition in the floodplain formation. 

Laurentian-Acadian Acidic Swamp: These forested wetlands are found in the temperate northeastern 

and north-central U.S., primarily in glaciated regions in the Laurentian-Acadian region. They occur on 

mineral soils that are nutrient-poor. There may be an organic epipedon, but the substrate is not deep 

peat. These basin wetlands remain saturated for all or nearly all of the growing season, and may have 

standing water seasonally. There may be some seepage influence, especially near the periphery. Red 

maple, ash species, red spruce (Picea rubens), balsam fir (Abies balsamea), and rarely black spruce 

(Picea mariana) are the most typical trees. The herbaceous and shrub layers tend to be fairly speciespoor. Mountain holly (Nemopanthus mucronatus) and fern (Osmunda spp.) are typical shrub and herb 

species. 

Eastern Boreal Semi-Treed Bog: These peatlands are found at the higher temperate and near-boreal 

latitudes of the northeastern and north-central U.S. and adjacent parts of Canada. Climate allows the rate 

of peat accumulation to exceed its decomposition, resulting in ombrotrophic and acidic peatlands in 

which the bog surface is raised above the water table. The surface morphology of the bog may be moreor-less level, domed, or eccentric. The vegetation is dominated by low ericaceous shrubs, including 

Sheep laurel (Kalmia angustifolia), bog laurel (Kalmia polifolia), Labrador tea (Ledum groenlandicum), 

and leatherleaf (Chamaedaphne calyculata), with patches of conifers, graminoids and bryophyte lawns. 
12

Secondary bog pools may be present. While the raised portion defines these bogs, fen vegetation is 

usually present along the perimeter. At Acadia, where this type is listed, the stands may more accurately 

be defined as Laurentian-Acadian Acidic Swamp (see above). Further review is needed. 

North-Central Appalachian Acidic Swamp: These swamps are distributed through the Central 

Appalachians south to Virginia. They are found in basins, or on gently sloping seepage lowlands. The 

acidic substrate is mineral soil, often with a component of organic muck; if peat is present, it usually 

forms an organic epipedon over the mineral soil rather than a true peat substrate. Eastern hemlock 

(Tsuga canadensis) is usually present and may be dominant. It is often mixed with deciduous wetland 

trees such as red maple or blackgum (Nyssa sylvatica). Sphagnum is an important component of the 

bryoid layer. Basin swamps tend to be more nutrient-poor and less species-rich than seepage swamps; in 

some settings, the two occur adjacent to each other with the basin swamp vegetation surrounded by 

seepage swamp vegetation on its upland periphery. 

Temperate & Boreal Bog & Fen

Acadian Maritime Bog: These ombrotrophic acidic peatlands occur along the northern Atlantic coast 

from Downeast Maine east into the Canadian maritimes. When these systems form in basins, they 

develop raised plateaus with undulating sedge and dwarf-shrub vegetation. Tufted leafless-bullrush

(Trichophorum caespitosum) may form sedge lawns on the raised plateau. The system may also occur as 

"blanket bogs" over a sloping rocky substrate in extreme maritime settings; here, dwarf-shrubs and 

Sphagnum are the dominant cover. Species characteristic of this maritime setting include common 

crowberry (Empetrum nigrum) and cloudberry (Rubus chamaemorus). Typical bog heaths such as sheep 

laurel, bog laurel, black huckleberry (Gaylussacia baccata), Labrador tea, and dwarf huckelberry 

(Gaylussacia dumosa) are also present. Morphological characteristics and certain coastal species 

distinguish these from more inland raised bogs. The distribution is primarily Canadian, and these 

peatlands are rare in the U.S. 

Laurentian-Acadian Acidic Basin Fen: These peatland systems range over a broad geographic area 

across the glaciated northeast to the Great Lakes and upper Midwest. The fens have developed in open 

or closed, relatively shallow basins with nutrient-poor and acidic conditions. Many occur in association 

with larger lakes or streams. The substrate is Sphagnum, and vegetation typically includes areas of 

graminoid and dwarf-shrub dominance. Leatherleaf is usually present and often dominant. Scattered 

stunted trees may be present. These fens often develop adjacent to open water. They lack the ribbed or 

reticulate microtopographical patterning of the patterned fen system. 

Laurentian-Acadian Alkaline Fen: These fens, distributed across glaciated eastern and central North 

America, develop in open basins where bedrock or other substrate influence creates circumneutral to 

calcareous conditions. They are most abundant in areas of limestone bedrock, and widely scattered in 

areas where calcareous substrates are scarce. The vegetation may be graminoid-dominated, shrubdominated, or a patchwork of the two; shrubby cinquefoil (Dasiphora fruticosa ssp. floribunda) is a 

common diagnostic shrub. The herbaceous flora is usually species-rich, and includes calciphilic 

graminoids and forbs. Sphagnum dominates the substrate; star campylium moss (Campylium stellatum) 

is an indicator bryophyte. The edge of the basin may be shallow to deep peat over a sloping substrate, 

where seepage waters provide nutrients. 
13

Temperate & Boreal Freshwater Marsh

Laurentian-Acadian Wet Meadow-Shrub Swamp and Marsh: These systems encompass shrub swamps 

and herbaceous emergent to submergent mineral-soil wetlands of the Northeast and upper Midwest. 

They are often associated with lakes and ponds, but are also found along streams, where the water level 

does not fluctuate greatly. The size of occurrences ranges from small pockets to extensive acreages. The 

emergent wetlands often have a patchwork of shrub and graminoid dominance; typical species include 

speckled alder (Alnus incana), white meadowsweet (Spiraea alba), sweetgale (Myrica gale), bluejoint 

(Calamagrostis Canadensis), tall sedge (Carex spp.), and Juncus effusus. Trees are generally absent and, 

if present, are scattered. Submergent wetlands include a variety of macrophytes, often with a border of 

non-persistent emergent vegetation dominated by pickerelweed (Pontederia cordata). The submergent 

vegetation zones may be severely impacted by non-native invasive aquatics including Eurasian water 

milfoil (Myriophyllum spicatum) and others. 

Northeast Vernal Pools: Vernal pools are temporary bodies of fresh water inhabited by many species of 

wildlife, some of which are totally dependent on the pools for their survival. They are often smaller than 

2 ha in size, and difficult to map because they typically occur as depressions within upland forests. 

These temporary freshwater pools provide critical habitats for breeding populations of amphibians and 

invertebrates dependent upon fishless environments for successful recruitment. Periodic drying of vernal 

pools eliminates fish populations and breeding populations of other predators such as bullfrogs (Rana 

catesbeiana Shaw) and green frogs (Rana clamitans Latreille). Thus, vernal pools provide an unusual 

low predation environment for many amphibians. In northeastern North America, vernal pools are 

typically found in upland forest and floodplain depression systems that are filled by spring rains, 

snowmelt, or seasonally raised water tables. Candidate systems within the Northeast Temperate Network 

where vernal pools may occur include the following: Laurentian-Acadian Floodplain Forest, Central 

Appalachian Floodplain, Acadian Lowland Spruce-Fir-Hardwood Forest, Laurentian-Acadian Northern 

Hardwood Forest, Laurentian-Acadian Pine-Hemlock-Hardwood Forest, and Appalachian HemlockHardwood Forest.

15

Field-Based Metrics for Assessing Wetland Ecological Integrity 

Overview of Rapid Metrics 

We compiled a list of indicators/metrics of condition for freshwater wetlands that covered the five major 

attributes: landscape context, size, biota, hydrology, and soils/physicochemistry (Figures 1 and 2), and 

which should reflect wetland composition, structure, and function (pattern and process). Because the 

same metrics apply to salt marshes, we retain information about metric variants appropriate to them in 

order to document metrics appropriate for monitoring all park wetlands. 

We first developed the criteria for the metrics at the broadest possible level: all freshwater wetlands. We 

then assessed whether some metrics needed “variants” based on the special characteristics of certain 

wetland formations, such as bogs and fens versus marshes. Finally, we asked whether certain systems 

might need more specific versions of these metrics. We are still reviewing this final step. 

A synopsis of the ecological metrics and ratings for freshwater wetlands is presented in Table 2, which 

is adapted from Faber-Langendoen et al. (2008a). Table 2 provides a brief overview and definition of 

each metric. Table 3 provides the details on the ratings for each metric, including variants for the metrics 

based on wetland types. For example, when rating Hydroperiod, three separate ratings are provided: (1) 

Non-riverine wetlands (excluding Bog and Fen), (2) Bog and Fen, and (3) Riverine. 

Metrics are categorized as either condition or stressor metrics. Condition metrics are used to assess the 

ecological characteristics of the system (e.g., hydroperiod of a wetland). They should also show a known 

response to anthropogenic stressors. Stressor metrics are used to measure activities or structures which 

are known or hypothesized to degrade the condition of the system. For example, measuring changes in 

water quality is a condition metric, whereas measuring the number of water diversions in the watershed 

of a wetland is a stressor metric. In addition to stressor metrics, we provide a stressors checklist that can 

help field crews assess the overall set of stressors found at a site. As noted in the section on Ecological 

Integrety, and as reflected in the conceptual model for wetlands, we keep condition and stressor metrics 

separate in order to be able to assess stressor-ecological response relationships (Kapos et al. 2002). 

The background, methods, and rationale for each metric are provided in the Protocols Section. A rating 

is developed, from excellent to poor, usually in a 4-category scale from A (Excellent) to D (Poor). 

Sometimes, a 3- or 5-category scale is used, depending on how sensitive the metric is to the effects of 

various stressors. Ratings and thresholds are provided as prototypes, and will be refined as the metrics 

are field tested and validated. Some metrics, such as vegetation structure, rely on knowledge of 

reference standard condition (see Section on Selection of Wetland Integrity Metrics). 

For each metric, data are collected based on field or office observation data, and those data are recorded. 

These metrics are designed to be rapid; that is, it should be possible to assess a wetland within two 

hours, plus two hours preparation time assessing the imagery. Field crew expertise should be akin to that 

needed for wetland delineation; that is, field crews should have some knowledge of hydrology, soils, and 

vegetation, sufficient to assess hydrologic dynamics, perhaps examine a soil core for mottling, and be 

able to identify all prominent exotic species in a region. Usually, once the crew leaves the field, the field 

forms are essentially complete. Unlike intensive metrics, there rarely are samples that require further 

analysis, and the data analysis is built into the rating system. There is never any need for intensive 

equipment-based measures. 

17

Table 2. Overview of rapid field-based (Level 2) metrics for assessing wetland integrity. Major Attribute 

Key Ecological Attribute Metric Name Tier Metric Type Metrics Definition 

Landscape Context 

Landscape Structure 

Landscape Connectivity 1,2 C Non-riverine: A measure of the percent of unfragmented landscape w

riverine types). Riverine: A measure of the degree to which the riverina floodplain area exhibits connectivity with adjacent natural systems (segment is 500 m upstream and 500 m downstream. 

Buffer Index 1,2 C An index of the overall area and condition of the buffer immediately su

using 3 measures: (1) Percent of Wetland with Buffer, (2) Average Bucorrection), and (3) Buffer Condition. Wetland buffers are vegetated, nareas that surround a wetland. 

Landscape Composition 

Surrounding Land Use Index 

1,2 S A measure of the intensity of human dominated land uses within a sp

as a catchment) from the center of the occurrence. Each land use typarea is assigned a coefficient ranging from 0.0 to 1.0 indicating its relasystem. 

Landscape Context Stressors 

Landscape Stressors Checklist 

2 S A checklist of stressors that could affect landscape context condition. 

Size Size Patch Size Condition (ha) 1,2 C A measure of the current size of the wetland (ha) relative to the origin

dividing the best estimate of historic size by current absolute size, mu

Absolute Patch Size (ha)* 1,2 C A measure of the current size (ha) of the occurrence or stand. Assess

stands of a type, globally. 

Vegetation Community 

Structure 

Vegetation Structure 2 C An assessment of the overall structural complexity of the vegetation la

multiple strata, age and structural complexity of canopy layer, and evimortality. 

Organic Matter Accumulation (coarse and fine debris) 

2 C An assessment of the overall organic matter accumulation, whether b

(non-forested wetlands) or coarse woody debris and snags (forested 

Community Composition 

Vegetation Composition 2 C An assessment of the overall species composition and diversity, inclu

of specific species diseases or mortality. 

Relative Total Cover of Native Plant Species 

2 C A measure of the relative percent cover of all plant species that are n

measured by estimating total absolute cover and subtracting total exo
18

Table 2. Overview of rapid field-based (Level 2) metrics for assessing wetland integrity (continued). Major Attribute 

Key Ecological Attribute Metric Name Tier Metric Type Metrics Definition Biotic Stressors Invasive Exotic Plant 

Species 

2 S A measure of the percent cover of a set of exotic plant species that are consider

Biotic Condition Stressors Checklist 

2 S A checklist of stressors that could affect biotic condition. 

 Hydrology 

Hydrological Regime 

Water Source 2 C An assessment of the extent, duration, and frequency of saturated or ponded co

affected by the kinds of direct inputs of water into, or any diversions of water aw

Hydroperiod 2 C An assessment of the characteristic frequency and duration of inundation or satu

typical year. 

Hydrologic Connectivity 

2 C An assessment of the ability of the water to flow into or out of the wetland, or to 

Hydrologic Stressors 

Upstream Surface Water Retention 

1 S A measure of the percentage of the contributing watershed which drains into wa

of storing surface water from several days to months. Applies to riverine system

Upstream/Onsite Water Diversions 

1 S A measure of the number of water diversions and their impact in the contributing 

wetland. Applies to riverine systems. 

Hydrologic Stressors Checklist 

2 S A checklist of stressors that could affect hydrologic condition. 

Soils (Physicochemistry) 

Physical Structure Physical Patch 

Types 

2 C A checklist of the number of different physical surfaces or features that may prov

Water Quality 2 C An assessment of water quality based on visual evidence of water clarity and euSoil Surface Condition 

2 S An assessment of soil surface disturbances (e.g. bare soil, tracks). 

Soil (Physicochemical) Stressors 

On-Site Land Use Index 

2 S A measure of the intensity of human dominated land uses within the site. Each l

within the site is assigned a coefficient ranging from 0.0 to 1.0 indicating its relatsystem. 

Soils (Physicochemical) Stressors Checklist 

2 S A checklist of stressors that could affect soils and physicochemical condition. 

Tier: 1 = Remote sensing based metric, 2 = Rapid field based metric. Metric Type: C = condition metric. S = stressor metric or checklist (g

contain metrics that are not used directly to assess integrity, but are considered informative). Ratings for each metric are provided in Table 3

Langendoen et al. (2008a) to show only wetland types found at NETN.
19

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity. 

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Landscape Context 

Landscape Connectivity: 

Non-Riverine 

1 C Intact: Embedded in 90-

100% natural habitat of around wetland, preferably within the watershed 

Variegated: Embedded in 60-90% natural habitat; 

Fragmented: Embedded 20-60% natural habitat; 

Riverine (–) 1 The combined total length 

of all non-buffer segments is less than 200 m (< 10%) for wadable (2-sided) sites, 100 m (<10%) for nonwadable (1-sided) sites. 

Combined length of all non-buffer segments is between 200 m and 800 m (10-40%) for “2-sided” sites; between 100 m and 400 m (10-40%) for “1-sided” sites. 

Combined length of all nobuffer segments is betwe800 and 1800 m (40-90%for “2-sided” sites; betwe400 m and 900 m (40-90for “1-sided” sites. 

 Buffer Index: 

Length 

1,2 C 

Buffer is >75–100% of occurrence perimeter. 

Buffer is >50–74% of occurrence perimeter. 

Buffer is 25–49% of occurrence perimeter. 

Width (–) Average buffer width of 

occurrence is > 200 m, adjusted for slope. 

Average buffer width is 100–199 m, after adjusting for slope. 

Average buffer width is 599 m, after adjusting for slope. 

Condition Buffer for occurrence is 

characterized by abundant (>95%) cover of native vegetation and little to no (<5%) cover of non-native plants, with intact soils, and little or no trash or refuse. 

Buffer for occurrence is characterized by substantial (75-95%) cover of native vegetation, low (5-25%) cover of non-native plants, intact or moderately disrupted soils, moderate or lesser amounts of trash or refuse, and minor intensity of human visitation or recreation. 

Buffer for occurrence is characterized by a mode(25-50%) cover of nonnative plants, and either moderate or extensive sodisruption, moderate or greater amounts of trash refuse, and moderate intensity of human visitator recreation. 
20

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued). 

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Surrounding Land Use Index 

Non-tidal 

1,2 S Average Land Use 

Score = 1.0-0.95 

Average Land Use Score = 0.80-0.95 

Average Land Use Score = 0.4-0.80 

Tidal S Land use index = 85-100 Land use index = 65–84. Land use index = 45–64. 

Landscape Stressors Checklist 

2 S 

Size Patch Size 

Condition 

1, 2 S Occurrence is at, or only 

minimally changed from, its current natural extent (<95%). Changes can include destroyed or severely disturbed; (e.g., large changes in hydrology due to roads, impoundments, development, humaninduced drainage; or changes caused by recent clear cutting) 

Occurrence is only modestly changed from its current extent (80-95% or more). Changes can include (see A). 

Occurrence is substantially changed from its natural extent (50-80%). Changes can include (see A). 

Absolute Patch Size 

1,2 Patch size is very large 

compared to other examples of the same type (e.g., top 10% based on known and historic occurrences, or areasensitive indicator species very abundant within occurrence). 

Patch size is large compared to other examples of the same type (e.g. within 10-30%, based on known and historic occurrences, or most area-sensitive indicator species moderately abundant within occurrence). 

Patch size is moderate compared to other examples of the same type, (e.g., within 30-70% of known or historic sizes; or many areasensitive indicator species are able to sustain a minimally viable population, or many characteristic species are bupresent). 
21

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued). 

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Vegetation (Biota) 

Vegetation Structure 

Bog & Fen 

2 C Peatland is supporting 

vegetation to its reference standard condition. Some very wet peatlands may not have any woody vegetation or only scattered stunted individuals. Woody vegetation mortality is due to natural factors and is not being influenced by anthropomorphic factors. Tree diameters and heights are near reference standard condition. 

Generally, peatland vegetation has only minor anthropogenic influences present or the site is still recovering from major past human disturbances. Mortality or degradation due to grazing, limited timber harvesting or other anthropomorphic factors may be present although not widespread. The site can be expected to meet reference standard condition in the near future if negative human influence does not continue. 

Peatland vegetation has been moderately influenced by anthropogenic factors. Expected structural classes or species are not present. Human factors may have diminished the standard condition for woody vegetation. The site will recover to reference standard condition only with the removal of degrading human influences and moderate recovery times. 

Floodplain & Swamp Forest 

Canopy a mosaic of small patches of different ages or sizes, including old trees and canopy gaps containing regeneration. Overall density moderate and average tree cover generally greater than 25%. 

Canopy largely heterogeneous in age or size, but with some gaps containing regeneration or some variation in tree sizes AND overall density moderate and greater than 25% tree cover. 

Canopy somewhat homogeneous in density anage, AND extremely dense or very open. Canopy cover may be very high or very low (>90%, <25%.) 

Freshwater Marsh (separate out vernal pools, prairie potholes) 

Vegetation is at or near reference standard condition in structural proportions. No structural indicators of degradation evident. 

Vegetation is moderately altered from reference standard condition in structural proportions. Several structural indicators of degradation evident. 
22

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued). 

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Aquatic Vegetation 

Vegetation is at or near reference standard condition in structural proportions. No structural indicators of degradation evident. 

Vegetation is moderately altered from reference standard condition in structural proportions. Several structural indicators of degradation evident. 

Organic Matter Accumulation (coarse and fine debris) 

Floodplain & Swamp Forest 

2 C A wide size-class diversity of downed coarse 

woody debris (logs) and standing snags, with 5–9 or more logs and snags exceeding 30 cm dbh and 2 m in length, and logs in various stages of decay. (An Excellent rating could be based on: with >10 logs and snags exceeding 30 cm dbh and 2 m in length.) 

A moderately wide size-class diversity of downed coarse woody debris (logs) and standing snags, with 1-4 logs and snags exceeding 30 cm dbh and 2 m in length, and logs in various stages of decay. 

Bog & Fen The site is characterized by an accumulation of 

peaty, hummocky, organic matter. There is some matter of various sizes, some very old. 

The site is characterized by some areas lacking an accumulation of peaty hummocky, organic matter. Size of materials does not vary greatly, nor do any appear old. 

Freshwater Marsh, Salt Marsh, & Aquatic Vegetation 

2 The site is characterized by a moderate amount of 

fine organic matter. There is some matter of various sizes, but new materials seem much more prevalent than old materials. Litter layers, duff layers, and leaf piles in pools or topographic lows are thin. In North American Pacific Salt Marsh, with 5-9 or more logs and snags exceeding 30 cm dbh and 2 m in length, and logs in various stages of decay. [An Excellent rating could be established using: >10 logs and snags exceeding 30 cm dbh and 2 m in length.] 

The site is characterized by occasional small amounts of coarse organic debris, such as leaf litter or thatch, with only traces of fine debris, and with little evidence of organic matter recruitment, or somewhat excessive littler. In North American Pacific Salt Marsh, with 1-4 logs and snags exceeding 30 cm dbh and 2 m in length, and logs in various stages of decay. 
23

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Vegetation Composition 

2,3 C Vegetation is at or near 

reference standard condition in species present and their proportions. Lower strata composed of appropriate species, and regeneration good. Native species sensitive to anthropogenic degradation are present, functional groups indicative of anthropogenic disturbance (ruderal or “weedy” species) are absent to minor, and full range of diagnostic / indicator species are present. 

Vegetation is close to reference standard condition in species present and their proportions. Upper or lower strata may be composed of some native species reflective of past anthropogenic degradation (ruderal or “weedy” species). Some indicator/ diagnostic species may be absent. 

Vegetation is different from reference standard condition in species diversity or proportions, but still largely composed of native species characteristic of the type. This may include ruderal (“weedy”) species. Regeneration of expected native trees may be sparse. Many indicator/diagnostic species may be absent. 

Relative Total Cover of Native Plant Species 

2,3 C 99% relative cover of native 

plant species. 

97-99% relative cover of native plant species. 

90-96% relative cover of native plant species. 

Invasive Exotic Plant Species 

2 S No key invasive exotic 

species present in area. 

Total abundance of key invasive exotic species less than 3%. 

Total abundance of key invasive exotic species 3-5% 

Biotic Condition Stressors Checklist 

2 S 
24

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Hydrology Water Source 2 Water source for site is 

precipitation, groundwater, tidal, natural runoff from an adjacent freshwater body, or system naturally lacks water in the growing season. There is no indication of direct artificial water sources. Land use in the local drainage area of the site is primarily open space or low density, passive uses. No large point sources discharge into or adjacent to the site. 

Water source is mostly natural, but site directly receives occasional or small amounts of inflow from anthropogenic sources. Indications of anthropogenic input include developed land or agricultural land (<20%) in the immediate drainage area of the site, or the presence of small storm drains or other local discharges emptying into the site, road runoff, or the presence of scattered homes along the wetland. that probably have septic systems. No large point sources discharge into or adjacent to the site. 

Water source is primarily urban runoff, direct irrigapumped water, artificially impounded water, or otheartificial hydrology. Indications of substantial artificial hydrology includ20% developed or agriculand adjacent to the site, the presence of major posources that discharge inadjacent to the site. 

Hydroperiod 

All Nonriverine wetlands, (except Bog & Fen) 

2 Hydroperiod of the site 

is characterized by natural patterns of filling or inundation and drying or drawdown. 

The filling or inundation patterns in the site are of greater magnitude. Greater or lesser duration than would be expected under natural conditions, but thereafter, the site is subject to natural drawdown or drying. 

The filling or inundation patterns in the site are characterized by natural conditions, but thereafter subject to more rapid or extreme drawdown or dryas compared to more natwetlands, OR the filling oinundation patterns in the are of substantially lower magnitude or duration thawould be expected under natural conditions, but thereafter, the site is subto natural drawdown or drying. 
25

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Bog & Fen (non-riverine) 

Hydroperiod of the site is characterized by stable, saturated hydrology, or by naturally damped cycles of saturation and partial drying. 

Hydroperiod of the site experiences minor altered inflows or drawdown/drying, as compared to more natural wetlands (e.g., ditching). 

Hydroperiod of the site is somewhat altered by greater increased inflow from runoff, or experiences moderate drawdown or drying, as compared to more natural wetlands (e.g., ditching). 

Hginedn

Salt Marsh 

Estuary Lagoon 

Area is subject to the full tidal prism, with two daily tidal minima and maxima. Area subject to natural interannual tidal fluctuations (range may be severely muted or vary seasonally), and is episodically fully tidal by natural breaching due to either fluvial flooding or storm surge. 

Area is subject to reduced, or muted, tidal prism, although two daily minima and maxima are observed. Area is subject to full tidal range more often than would be expected under natural circumstances, because of artificial breaching of the tidal barrier. 

Area is subject to muted tidal prism, with tidal fluctuations evident only in relation to extreme daily highs or spring tides. Area is subject to full tidal range less often than would be expected under natural circumstances due to management of the breach to prevent its opening. 

ApdpdAo

Riverine Most of the channel 

through the site is characterized by equilibrium conditions, with no evidence of severe aggradation or degradation (based on the field indicators listed in Section II.E.4). 

Most of the channel through the site is characterized by some aggradation or degradation, none of which is severe, and the channel seems to be approaching an equilibrium form (based on the field indicators listed in Section II.E.4). 

There is evidence of severe aggradation or degradation of most of the channel through the site (based on the field indicators listed in Section II.E.4) 

DathoS
26

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Hydrologic Connectivity 

All nonriverine wetlands, excluding Bogs & other isolated wetlands, Salt Marsh (see below) 

2 C Rising water in the site 

has unrestricted access to adjacent upland, without levees, excessively high banks, artificial barriers, or other obstructions to the lateral movement of flood flows. 

Lateral excursion of rising waters in the site is partially restricted by unnatural features, such as levees or excessively high banks, but less than 50% of the site is restricted by barriers to drainage. Restrictions may be intermittent along the site, or the restrictions may occur only along one bank or shore. Flood flows may exceed the obstructions, but drainage back to the wetland is incomplete due to impoundment. 

Lateral excursion of rising waters in the site is partially restricted by unnatural features, such as levees or excessively high banks, and 50-90% of the site is restricted by barriers to drainage. Flood flows may exceed the obstructions, but drainage back to the wetland is incomplete due to impoundment. 

Acolecothredna

Bogs and other isolated wetlands 

No connectivity Partial connectivity. (e.g., 

ditching or where duripan is intentionally broken by drilling or blasting] 

S

Salt Marsh Average tidal channel 

sinuosity >4.0; absence of channelization. Marsh receives unimpeded tidal flooding. Total absence of tide gates, flaps, dikes culverts, or human-made channels. 

Average tidal channel sinuosity =2.5 - 3.9. Marsh receives essentially unimpeded tidal flooding, with few tidal channels blocked by dikes or tide gates, and human-made channels are few. Culvert, if present, is of large diameter and does not significantly change tidal flow, as evidenced by similar vegetation on either side of the culvert. 

Average tidal channel sinuosity = 1.0 - 2.4. Marsh channels are frequently blocked by dikes or tide gates. Tidal flooding is somewhat impeded by small culvert size, as evidenced in obvious differences in vegetation on either side of the culvert. 

A<eaectobc
27

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Riverine—Unconfined 

C Entrenchment ratio is 

>4.0. Completely connected to floodplain (backwater sloughs and channels) 

Entrenchment ratio is 1.4-2.2. Minimally disconnected from floodplain by dikes, tide gates, elevated culverts, etc. 

Entrenchment ratio is <1.4. Moderately disconnected from floodplain by dikes, tide gates, elevated culverts, etc. 

Riverine—Confined 

C Entrenchment ratio is 

>1.4. 

Entrenchment ratio is 1.0-1.4. 

Entrenchment ratio is <1.0. 

Upstream Surface Water Retention 

Riverine wetlands only? 

1 S <5% of drainage basin 

drains to surface water storage facilities 

>5-20% of drainage basin drains to surface water storage facilities 

>20 - 50% of drainage basin drains to surface water storage facilities 

Upstream/Onsite Water Diversions 

Riverine wetlands only? 

1 S No upstream, onsite, or 

nearby downstream water diversions present 

Few diversions present or impacts from diversions minor relative to contributing watershed size. Onsite or nearby downstream diversions, if present, appear to have only minor impact on local hydrology. 

Many diversions present or impacts from diversions moderate relative to contributing watershed size. Onsite or nearby downstream diversions, if present, appear to have a major impact on local hydrology. 

Hydrologic Stressors Checklist 

2 S 

Soils (PhysicoChemistry) 

Physical Patch Types 

C Physical patch types typical of reference standard 

condition are present (see checklist). 

Some physical patch types typical of reference standard condition are lacking (see checklist). 
28

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

Water Quality 2 C There is no visual 

evidence of degraded water quality. Wetland species that respond to un-naturally high nutrient levels are minimally present, if at all. Water is clear with no strong green tint or sheen. 

Some negative water quality indicators are present, but limited to small and localized areas within the wetland. Wetland species that respond to unnaturally high nutrient levels may be present but are not dominant. Water may have a minimal greenish tint or cloudiness, or sheen. 

Negative water quality indicators or wetland species that respond to unnaturally high nutrient levels are common. Wetland is not dominated by these vegetation species. Sources of water quality degradation are typically apparent. Water may have a moderate greenish tint, sheen or other turbidity with common algae. 

Soil Surface Condition 

All freshwater wetlands 

2 C,S Bare soil areas are 

limited to naturally caused disturbances such as flood deposition or game trails. 

Some amount of bare soil due to human causes is present but the extent and impact is minimal. The depth of disturbance is limited to only a few inches and does not show evidence of ponding or channeling water. Any disturbance is likely to recover within a few years after the disturbance is removed. 

Bare soil areas due to human causes are common and will be slow to recover. There may be pugging due to livestock resulting in several inches of soil disturbance. ORVs or other machinery may have left some shallow ruts. Damage is not excessive and the site will recover to potential with the removal of degrading human influences and moderate recovery times. 

Salt marsh Excluding mud flats, 

bare soils are limited to salt panes. 

Limited exposure of bare soils caused by erosion of marsh and channel banks due to excavation or marine traffic. 

Frequent exposure of bare soils caused by erosion of marsh and channel banks due to excavation by marine traffic. (Excessive animal grazing?) 
29

Table 3. Summary of ratings for rapid field-based (Level 2) metrics used to assess wetland integrity (continued).

Metric Rating Criteria 

Major Attribute Metric Name Tier 

Metric Type Excellent (A) Good (B) Fair (C) 

On-site Land Use 

2 S Average Land Use 

Score = 1.0-0.95 

Average Land Use Score = 0.80-0.95 

Average Land Use Score = 0.4-0.80 

Soils (Physicochemical) Stressors Checklist 

2 S 

Tier: 1 = Remote sensing based metric, 2 = Rapid field based metric. Metric Type: C = condition metric, and S = stressor metric or checklicontain metrics that are not used directly to assess integrity, but are considered informative). References to “riverine” etc follow standard H

protocols for each metric are provided separately in the Section on Rapid Field Metric Descriptions. Adapted from Faber-Langendoen et al. types found at NETN. 

31 

Stressor Checklist 

Stressor checklists can be useful as additional information when evaluating the ecological integrity of an 

occurrence (Kapos et al. 2002). Typically, they are an aid to further understanding the overall condition 

of the wetland. In some cases, where stressors appear to be having a negative impact on the site, but the 

condition metrics do not reflect these impacts, it may lead to changes in the overall ecological integrity 

rank of a wetland. This should only be done in exceptional circumstances. The need for manual overrides may suggest that the current condition metrics may be insensitive to degradation due to certain 

stressors, and future adjustments to the metrics used may be needed. 

Stressors are listed if they are observed or inferred to occur, but are not included if they are projected to 

occur in the near term, but do not yet occur. Stressors may be characterized in terms of scope and 

severity. Scope is defined as the proportion of the occurrence of an ecosystem that can reasonably be 

expected to be affected (that is, subject to one or more stresses) by the threat with continuation of 

current circumstances and trends. Within the scope (as defined spatially and temporally in assessing the 

scope of the threat), severity is the level of damage to the ecosystem from the threat that can reasonably 

be expected with continuation of current circumstances and trends by excluding potential new threats). 

For ecosystems, severity is typically assessed by known or inferred degree of degradation or decline in 

integrity to one or more key ecological attributes. 

Instructions for assessing Stressors are provided in the Table 4. A The stressor checklists are provided in 

Table 5. 

Table 4. Instructions for using the Stressors Checklists (the following guidance is under review, and is adapted 

from Master et al. (2009)). 

Threat Scope (typically assessed within a 

10-year time frame) 

Pervasive = Affects all or most (71-100%) of total 

occurrence

Large = Affects much (31-70%) of the total occurrence

Restricted = Affects some (11-30%) of the total occurrence

Small = Affects a small (1-10%) proportion of the total 

occurrence

Threat Severity (within the scope; 

assessed within max of 10 yrs) 

Extreme = likely to extremely degrade/destroy or eliminate 

occurrence (71-100%)

Serious = likely to seriously degrade/reduce occurrence 

(31-70%)

Moderate = likely to moderately degrade/reduce 

occurrence (11-30%)

1. Record an estimate 

of the scope and 

severity for applicable 

individual 

stressors/threats to the 

ecosystem.[see 

Stressors Checklist] 

Unknown

Slight = likely to only slightly degrade/reduce occurrence 

(1-10%)

Threat Impact Scope 

Calculation Pervasive Large Restricted Small

Extreme Very High High Medium Low 

Serious High High Medium Low 

Moderate Medium Medium Low Low 

Severity 

Slight Low Low Low Low 

2. The Impact of each 

Stressor/Threat is 

calculated 

automatically from the 

Scope and Severity 

values (right), and a 

letter grade is assigned 

(below, right). 

Threat Impact A = Very High 

B = High 

C = Medium 

D = Low 
32 

Table 4. Instructions for using the Stressors Checklists (the following guidance is under review, and is adapted 

from Master et al. (2009)) (continued). 

3. After Impact has been recorded for all applicable stressors/threats, use these impact values to calculate an overall threat 

impact for the major ecosystem attribute (landscape context, vegetation, soils, hydrology) according to the categories below. 

Professional judgment is used to assign an Overall Threat Impact for each Major Ecological Attribute [an automated procedure 

may be made available in the future]. 

If the value for one or more impacts is a range, evaluate the highest (single and range) values for every threat and then 

evaluate the lowest values to determine the range of overall threat impact. For example, three Medium-Low impacts could 

indicates an overall threat impact of High–Low, and four Medium-Low impacts indicates an overall threat impact of HighMedium.

1 or more Very High, OR 

2 or more High, OR 

1 High + 2 or more Medium 

1 High, OR 

3 or more Medium, OR

2 Medium + 2 Low, OR

1 Medium + 3 or more Low 

1 Medium, or 4 or more Low 

Impact Values of Stressor Categories 

1 to 3 Low 

4. After Impact has been recorded for the major ecological attributes, use these impact values to calculate an overall threat 

impact to the occurrence, [guidance is needed]. 

If the value for one or more major ecological attributes is a range, evaluate the highest (single and range) values for every 

major attribute and then evaluate the lowest values to determine the range of overall threat impact. For example, three 

Medium-Low impacts indicates an overall threat impact of High–Low, and four Medium-Low impacts indicates an overall threat 

impact of High-Medium. 
33 

Table 5. Stressor Checklist Worksheets for Assessment Area (site). Checklist adapted from Collins et al. (2006). 

HYDROLOGY Scope Severity Impact 

Point Source (PS) Discharges (POTW, other non-stormwater discharge) 

Non-point Source (Non-PS) Discharges (urban runoff, farm drainage) 

Flow diversions or unnatural inflows 

Dams (reservoirs, detention basins, recharge basins) 

Flow obstructions (culverts, paved stream crossings) 

Weir/drop structure, tide gates 

Dredged inlet/channel 

Engineered channel (riprap, armored channel bank, bed) 

Dike/levees 

Groundwater extraction 

Ditches (borrow, agricultural drainage, mosquito control, etc.) 

Actively managed hydrology 

Comments 

SOILS (PHYSICOCHEMISTRY) Scope Severity Impact 

Filling or dumping of sediment or soils (N/A for restoration areas) 

Grading/compaction/road (N/A for restoration areas) 

Plowing/Discing (N/A for restoration areas) 

Resource extraction (sediment, gravel, oil and/or gas, peat, logging) 

Vegetation management 

Excessive sediment (erosion) or organic debris from watershed 

Excessive runoff from watershed 

Nutrient impaired (PS or Non-PS pollution) 

Heavy metal impaired (PS or Non-PS pollution) 

Pesticides or trace organics impaired (PS or Non-PS pollution) 

Bacteria and pathogens impaired (PS or Non-PS pollution) 

Trash or refuse 

Comments 

VEGETATION Scope Severity Impact 

Mowing (within site) 

Livestock grazing 

Excessive herbivory (within site) 

Excessive human visitation 

Predation and habitat destruction by non-native vertebrates (e.g., 

domestic predators, such as feral pets) 

 

Tree cutting/sapling removal 

Removal of woody debris 

Treatment of non-native and nuisance plant species 

Pesticide application or vector control 

Evidence of fire 

Evidence of flood 

Biological resource extraction or stocking (fisheries, aquaculture) 

Excessive organic debris in matrix (for vernal pools) 

Lack of vegetation management to conserve natural resources 

Invasives (animals, pathogens) [see also Invasive Exotics metric for plants] * 

Lack of appropriate treatment of invasive plant species adjacent to site or buffer 

Comments 

ADJACENT LAND USE Scope Severity 

Urban residential 

Industrial/commercial 

Military training/Air traffic 

Dryland farming 

Intensive row-crop agriculture 

Orchards/nurseries 

Commercial feedlots 

Dairies 

Ranching (enclosed livestock grazing or horse paddock or feedlot) 

Transportation corridor 

Distance to nearest transportation corridor or road (measure) Distance 

Rangeland (livestock rangeland also managed for native vegetation) 

Sports fields and urban parklands (golf courses, soccer fields, etc.) 

Passive recreation (bird-watching, hiking, etc.) 

Active recreation (off-road vehicles, mountain biking, hunting, fishing) 

Physical resource extraction (rock, sediment, oil/gas) 

Biological resource extraction (aquaculture, commercial fisheries) 

Boat traffic (frequency and distance from site) 

Comments 
34 

Overview of Intensive Metrics 

At this time, intensive metrics are still under development. Neckles et al. (2007) provide a series of 

metrics focused on wet meadows and fens. These metrics will need to be extended to cover all wetlands. 

A summary of possible metrics is provided in Table 6. 

Table 6. Overview of a draft set of intensive field based metrics for assessing freshwater wetland integrity. Metric 

Type: C = condition based metric, and S = stressor metric. 

Category 

Key 

Ecological 

Attribute 

Metric Name Tier Metric 

Type Metrics Definition 

Landscape 

Context & Size 

 (Metrics could be taken 

from Level 2 assessment) 

 

Biota Community 

Structure 

Vegetation Structure 3 C A measure of the overall structural 

complexity of the vegetation layers, 

including presence of multiple strata, 

age and structural complexity of 

canopy layer. 

 Organic Matter 

Accumulation (coarse and 

fine debris) 

3 C A measure of the overall organic 

matter accumulation, whether both 

fine and coarse litter (non-forested 

wetlands) or coarse woody debris and 

snags (forested wetlands). 

 Community 

Composition 

Floristic Quality Index 3 C A measure of the mean conservatism 

of all the native species growing in the 

wetland. The index reflects increasing 

sensitivity of plant species to human 

disturbance. 

Invasive Exotic Plant 

Species 

3 S A measure of the percent cover of a 

set of exotic plant species that are 

considered invasive. Similar to rapid 

assessment metric, but measured 

quantitatively 

Hydrology Hydrological 

Regime 

Index of Hydrological 

Alteration 

3 C This metric uses daily stream flow 

data to determine trends at one site or 

determine differences between preand post-impacts of sites. 

Surface Water Level 3 C A measure of the change in surface 

water level over time. 

Groundwater Level 2 C A measure of the changes in ground 

water level over time. 

Soils/ 

Physicochemestry 

Physical 

Structure 

Bank Stability 3 C This metric assesses the stability and 

condition of the streambanks. 

Soil Bulk Density C Soil bulk density is a ratio of the 

mass/volume of the soil. This metric 

measures compaction of soil 

horizons. 

 Water 

Chemistry 

Water Quality 3 C Consult with Freshwater Team. 

 pH (surface water, 

groundwater) 

3 C A measure of the status and trend in 

acidity of both the surface water and 

the ground water. 

 Conductivity (surface 

water, groundwater) 

3 C A measure of the status and trend in 

conductivity of both the surface water 

and the ground water. 

 Soil 

Chemistry 

Soil Organic Carbon 3 C This metric measures the amount of 

soil organic carbon present in the soil. 
35

Wetland Integrity Scorecard 

Introduction 

It is challenging to integrate or summarize indicators into indices that highlight the overall condition of 

ecosystems and help guide management decisions. This challenge is part of a larger need to develop 

meaningful indices of terrestrial and wetland ecological integrity (Andreasen et al. 2001), akin to Karr’s 

Index of Biotic Integrity (IBI) for aquatic systems (Karr and Chu 1999). Properly constructed, such 

indices can be useful as an early warning system for ecological degradation and for priority setting 

among degraded systems, or for protection of those in more pristine condition. These indices should be 

useable both for assessments, where a snapshot of the current condition is taken, and for monitoring, 

where changes in condition are tracked over time (Andreasen et al. 2001). 

Individual metrics can be aggregated to provide a rating of the condition of each the major ecological 

attributes - landscape context, size, biota, hydrology, and physicochemical condition (aggregating by 

key ecological attribute is typically not needed, as they often have only one or two metrics). The 

categories can be further aggregated into an overall Index of Ecological Integrity (IEI) rank. IEIs can be 

calculated at multiple scales (e.g., sample plot, polygon, occurrence, site, jurisdictional area), depending 

on the sampling design and the scale of the question (see Section F). 

A Point-Based Approach 

In our point-based approach, the following assumptions are made: each metric is treated independently 

and assigned a rating, which is then converted to a score. For each metric, the scaling is attempting to 

establish a rating for degree of degradation. Essentially, every A rating means the same thing – the 

ecological attribute is well within its natural or acceptable range of variation. Thus, a rating of A is 

reflective of a “higher” score than a rating of B, even though a letter rating does not indicate the 

magnitude of the difference between A or B (i.e., if instead of A we said “95” and instead of C, we 

stated “71,” we would know they were 24 units apart). Since the exact mathematical distribution of the 

A or B ratings is not defined, the values cannot meaningfully be added, subtracted, etc. None-the-less, in 

a well constructed set of metrics, we have explicitly attempted to scale what is meant by A, B, C and D 

within and across metrics. 

Thus, although ordinal scales provide less resolution and, to some degree, make it harder to combine 

metrics, they are more easily justified in terms of biological, ecological, and mathematical criteria. As 

stated by Sutula et al. (2006), “...ordinal scales require only the ability to rank wetlands based on their 

relative similarity to the desired assessment endpoint without knowing precisely how close the condition 

is to that endpoint or to the next highest rating category.” The key is to scale the ordinal values so that 

the full range of each of the metrics is indicating something comparable in terms of ecological integrity. 

Given that premise, it can be acceptable to use a relatively simple, point-based approach to both score 

and aggregate the metrics together, without developing any statistical applications. The aggregation 

helps provide users with a readily interpretable set of indices that highlight the integrity of major 

attributes of the system. The overall interpretation should remain focused on the general ratings of A - D 

and not on the details of the points themselves (i.e., whether an A of 95 is better than an A of 89). In 

addition, the original metrics themselves are available to further explain the reasons for the aggregated 

scores. 

When aggregating metrics or categories, an arithmetic mean can be calculated which assumes all 

categories have an equal weight and contribution to the overall integrity index. One could also weight 
36

some metrics or major attributes more than others, so that they contribute an overall higher proportion of 

the total points to the final index. As noted above, another approach is to add some rules, so that specific 

combinations of metrics or attributes define a particular level of integrity. 

For the point-based approach developed here, the default set of points for the basic four category rating 

scheme are A= 5, B = 4, C = 3, D = 1. The weights are derived from Karr’s Index of Biotic Integrity 

(IBI) approach (Karr and Chu 1999), where 5 (good), 3 (fair) and 1 (poor) points were used. Distinctions 

between Excellent (A) and Good (B) can be subtle, compared to the C/D break, so only a single point 

separates them. Some metrics have a five or six point rating scheme (A-E, or A-F), and the points are 

then spread out evenly from 5 to 1. The metrics are rolled up by major ecological attribute, and in turn, 

these attributes are rolled up into an overall Index of Ecological Integrity (IEI). 

Addressing Uncertainty when Assessing Metrics 

There are times when it may be difficult to assign a rating value to a metric. Rather than be forced to 

assign an exact value, it may be valuable to record the level of uncertainly by using a “range-rating.” 

That is, an assessor may not be able to decide between an A and a B rating for a metric. In this case, it 

may be best to assign an AB rating (that is, the rating may be either A or B). The low and high scores 

(e.g., A = 5, B = 4) will both be used in the calculation. When roll-ups to the four categories are 

completed, both the total low scores and high scores across the metrics are calculated, and if the final 

low and high score span two ratings, a range rating is assigned to the major attribute. A similar approach 

can be used for the overall IEI. The use of range-ranks should only be applied in cases of great 

uncertainty. Exact ratings are encouraged. But the range-rating is helpful whenever rating proves 

challenging because of unusual situations in the field or assessor inexperience with a metric. 

Role of Stressor Checklists 

Stressor checklists are used only for informative purposes, as an aid to further understanding the overall 

condition of the wetland. In some cases, where stressors appear to be having a negative impact on the 

site, but the condition metrics do not reflect these impacts, it may be important to over-ride the 

calculated IEI. This should only be done in exceptional circumstances. The need for manual over-rides 

may suggest that the current condition metrics may be insensitive to degradation of certain stressors, and 

future adjustments to the metrics may be needed. 

Weighting Metrics by Formation 

Not all metrics are equally relevant to each formation. A metric such as Vegetation Structure has greater 

interpretive value for forested wetlands, where changes in structure can be linked to ecological integrity, 

than it does to freshwater marshes, where changes in structure are more subtle. Thus the rating protocols 

specified below may need to be adjusted by wetland formation (see Table 1). 

The Rapid Assessment Ecological Integrity Scorecard 

We first structure the system so that each metric is assigned a weight, based on how important it is 

considered to be in evaluating ecological integrity. Second, each rating for a metric is assigned a point value 

with A = 5 points, B = 4 points, etc. When a field value is assigned for a metric (e.g., the Buffer Index is 

given a B rating), it is first converted to a point rating (i.e., B = 4), then the points are multiplied by the 

weight (4 x 1 = 4). The weighted scores for all metrics within a major attribute (e.g., Landscape Context) are 

then summed and divided by the sum of the weights, giving a weighted average score. Finally, the weighted 

average of each attribute can be summed and divided by the total number of attributes (or if the attributes 

themselves are also weighted, then the division would be based on the weighted sum of those attributes). 

The point-based approach is consistent with that of many IBI scoring methods (e.g., Karr and Chu 1999). 
37

Landscape Context 

Rate the Landscape Context metrics according to their specified ratings (see Table 3). Use the scoring 

table below (Table 7) to roll up the metrics into an overall Landscape Context rating. 

Rational for Scoring: Three metrics are judged equally important. 

Size 

Rate the size metrics according to their specified ratings (see Table 3). Use the scoring table below 

(Table 7) to roll up the metrics into an overall size rating. 

Rationale for Scoring: Absolute Size is always used as a metric, but Relative Size is optional. Even 

when used, it carries less weight than current absolute size. The focus is on current condition, not 

historic patterns per se. 

Table 7. Landscape Context rating calculation for wetlands in the Northeast Temperate Network. 

Metric A* B C D Weight Weighted Score 

Landscape Connectivity 5 4 3 1 1 

Buffer Index 5 4 3 1 1 

Surrounding Land Use 5 4 3 1 1 

 ∑ = sum of 

weights 

∑ = sum of weighted 

scores 

 

Score = (sum of 

weighted scores / sum 

of weights) 

* Landscape Context Rating: A = 4.5 – 5.0; B = 3.5 – 4.4, C = 2.5 – 3.4; D = 1.0 – 2.4 

Table 8. Size rating* calculation for wetlands in the Northeast Temperate Network. 

Metric A B C D Weight Weighted Score 

Absolute Patch Size (ha)** 5 4 3 1 1 

Patch Size Condition (ha)** 5 3 1 0.5 

 ∑ = sum of 

weights 

∑ = sum of weighted 

scores 

 

Score = (sum of 

weighted scores/sum 

of weights)

* Size Rating: A = 4.5-5.0; B = 3.5-4.4; C = 2.5-3.4; D = 1.0-2.4

** optional metric 

Vegetation (Biota) 

Rate the vegetation metrics according to their specified ratings (see Table 3). The scoring table below 

(Table 9) is used to roll up the metrics into an overall vegetation rating. 

Rationale for Scoring: Each of the metrics is judged to be equally important as a measure of biotic 

(vegetation) integrity. 
38

Hydrology 

Rate the metrics according to their specified ratings (see Table 3). Use the scoring table below (Table 

10) to roll up the metrics into an overall hydrology rating. 

Rationale for Scoring: Each of the hydrologic metrics is judged to be equally important to the overall 

hydrologic integrity. 

Soils (Physicochemistry) 

Rate the physicochemistry metrics according to their specified ratings (see Table 3). Use the scoring 

table below (Table 11) to roll up the metrics into an overall physicochemistry rating. 

Rationale for Scoring: Physical patch types is weighted less heavily than the other two metrics because 

it is not yet clear how much diversity of patch types is an inherent property of ecological integrity. 

Water quality may be difficult to observe in the field for floodplain and for bog and fen systems, where 

standing water is often not present. 

Table 9. Vegetation (Biota) rating* calculation for wetlands in the Northeast Temperate Network. 

Metric A B C D E Weight Weighted Score 

Vegetation Structure 5 4 3 1 1 

Organic Matter Accumulation 

(coarse and fine debris) 5 3 1 1 

Vegetation Composition 5 4 3 1 1 

Relative Total Cover of Native Plant 

Species 5 4 3 2 1 1 

 ∑ = sum of 

weights 

∑ = sum of 

weighted scores 

 

Score = (sum of 

weighted scores / 

sum of weights) 

*Vegetation (Biota) Rating: A = 4.5–5.0; B = 3.5–4.4; C = 2.5–3.4; D = 1.0–2.4 

Table 10. Hydrology rating* calculation for wetlands in the Northeast Temperate Network. 

Metric A B C D Weight Score 

Water Source 5 4 3 1 1 

Hydroperiod 5 4 3 1 1 

Hydrologic Connectivity 5 4 3 1 1 

 ∑ = sum of 

weights 

∑ = sum of 

weighted scores 

 

Score = (sum of 

weighted scores / 

sum of weights) 

*Hydrology Rating: A = 4.5–5.0; B = 3.5–4.4; C = 2.5–3.4; D = 1.0–2.4 
39

Table 11. Soils (Physicochemistry) rating* calculation for wetlands in the Northeast Temperate Network. 

Metric A B C D Weight Weighted Score 

Physical Patch Types 5 3 1 0.5 

Water Quality** 5 4 3 1 1 

Soil Surface Condition 5 4 3 1 1 

 ∑ = sum of 

weights 

∑ = sum of weighted 

scores

 

Score = (sum of 

weighted scores / sum 

of weights)

* Soils (Physicochemistry) Rating: A = 4.5–5.0; B = 3.5–4.4; C = 2.5–3.4; D = 1.0–2.4 

**optional metric 

Overall Index of Ecological Integrity (IEI) Rank 

The overall index of ecological integrity is based on a roll-up of the scores for each of the major 

ecological attributes (see scorecard metrics above). The table (Table 12) used to calculate overall 

ecological integrity is structured so that the score for each of the major attributes is provided, along with 

the overall index. Managers may find trends at both levels helpful when assessing the integrity of 

wetlands in their park. 

Rationale for Scoring: Each of the major attributes is given a specific weight. In the current model, we 

weight size and soils less heavily than the other factors. Soils and size are down-weighted because at this 

time we are not as confident that the rapid metrics for these attributes can be as readily used to assess 

ecological integrity as metrics for the other attributes. In addition, consideration is being given to a rule 

for interactions between size and landscape context scores, whereby when landscape context scores are 

high (i.e., the wetland is found in an intact natural landscape), less weight is given to size, whereas as 

landscape context decreases in integrity, increasing weight is given to size. 

An example is provided in Table 13. In this example, the Weighted Attribute Score column multiplies 

the attribute score (e.g., for size the attribute score is 6.5 / 1.5 = 4.3 by the weight (e.g. for size the 

weight is 0.5) to get a Weighted Attribute Score (e.g., for Size = 2.2). The weighted score is summed, as 

are the weights. The “Score” column is calculated by dividing the total sum of weighted attribute scores 

(in this example: 4.3+2.2+3.6+4.0+2.0 = 16.1) by the total sum of attribute weights (1+0.5+1+1+0.5 = 

4). 

The Intensive Assessment Ecological Integrity Scorecard 

At this time, the development of intensive metrics is still preliminary, based in part on the work of 

Neckles et al. (2007) and others (Miller et al. 2006a, 2006b). Thus, the scorecard cannot yet be fully 

developed. Once the intensive metrics are agreed on and ratings for them are established, a scorecard 

can be generated. If the scorecards for the rapid and intensive metrics are structured in similar ways, it 

will be possible to evaluate the two sets of scores for comparable metrics and by major attribute to see 

how they compare. 

Adapting the Methods Over Time 

It is important to remember that our efforts to assess ecological integrity are approximations of our 

current understanding of these systems. In reality, ecosystems are far too complex to be fully 

represented by a suite of metrics and attributes. Moreover, our rapid metrics, indices and scorecards 

must be flexible enough to allow change over time as our knowledge grows. What is important is that 
40

we present as clearly as possible methods used in conducting our assessments, so that communication 

and understanding is fostered among people with different backgrounds, goals, and points of view. 

Table 12. Overall IEI rank* calculation for wetlands in the Northeast Temperate Network. 

Category A B C D Weight Weighted Score 

Landscape Context 5 4 3 1 1 

Size 5 4 3 1 0.50 

Vegetation 5 4 3 1 1 

Hydrology 5 4 3 1 1 

Soils (Physicochemistry) 5 4 3 1 0.50 

 

∑ = sum 

of 

weights 

∑ = sum of 

weighted scores 

 

Score = (sum of 

weighted scores / 

sum of weights) 

*IEI Rating: A = 4.5–5.0; B = 3.5–4.4; C = 2.5–3.4; D = 1.0–2.4 

Table 13. Example of scores and ranks for metrics, factors, and the overall ecological integrity for a Level 

2 Rapid Field-based Assessment. 

Major Attributes 

Metric 

Assigned 

Metric 

Rating 

Assigned 

Metric 

Points 

Weight 

(W) 

Metric 

Score 

(M) 

Weighted 

Attribute 

Score 

(WAS) 

Rank 

Factor 

Rank 

Score 

Index of 

Ecological 

Integrity 

Landscape Context 4.3 (4.3*1) B 

Landscape Connectivity A 5 1 5 

Buffer Index B 4 1 4 

Surrounding Land Use B 4 1 4 

 ∑ = 3 ∑ = 13 

Size 2.2 (4.3*0.5) B 

Patch Size Condition A 5 0.5 2.5 

Absolute Size B 4 1 4 

 ∑ = 1.5 ∑ = 6.5 

Vegetation 3.6 (3.6*1) B 

Vegetation Structure C 3 1 3 

Organic Matter Accumulation C 3 0.5 1.5 

Vegetation Composition B 4 1 4 

Relative Total Cover of 

Native Plant Species B 4 1 4 

 ∑ = 3.5 ∑ = 12.5 

Hydrology 4.0 (4.0*1) B 

Water Source C 3 1 3 

Hydroperiod B 4 1 4 

Hydrologic Connectivity A 5 1 5 

 ∑ = 3 ∑ = 12 

Soils (Physicochemistry) 2.0 (4.0*0.5) B 

Physical Patch Types B 4 0.5 2 

Water Quality B 4 1 4 

Soil Surface Condition B 4 1 4 

 ∑ = 2.5 ∑ = 10 

∑ = 16.1 (4) 

Rating A = 4.5-5.0, B = 3.5-4.4, C = 2.5-3.4, D = 1.0-2.4 4.0 B 
41

Sampling Design and Field Methods 

Sampling Design 

A sampling design is needed to implement both a rapid and an intensive wetland monitoring program; 

however, creating such a design is beyond the scope of this report. At this time, there is no established 

sampling design or field survey methods for NETN wetlands. It is possible that the rapid assessment 

protocol will be completed for all NETN wetlands–essentially a comprehensive survey. Otherwise a 

sampling design will be needed. What follows below are a series of observations and guidelines that 

may be helpful for designing a field survey protocol for NETN wetlands. 

Overview of Sampling Methods 

Field methods for applying ecological integrity assessments vary depending on the purpose of the 

assessment. Several general comments can be provided in the context of a rapid assessment. First, the 

level of inference must be established. There are perhaps three options: 1) Treat the entire set of wetland 

area as one population; 2) Treat all wetland polygons as one population; or 3) Stratify either 1 and 2 by 

some important variable, such as wetland type or ecoregion. 

From a monitoring perspective, the first option is perhaps the most straightforward. A comprehensive 

map of the areas of wetland is required. A sampling design is used to select a set of points for 

monitoring. This approach would be the most similar to the forest sampling design. The level of 

inference is then most directly about “wetlands” overall, and one may not be able to infer much about 

particular wetland types or wetland areas. 

The second and third options are commonly used for ecological surveys, where an occurrence of a 

wetland is defined for a site, either the entire wetland or a specific wetland type (e.g., Acadian Maritime 

Bog). Within the site or type, either the entire area or a subset is surveyed. They surveyed area is the 

Ecological Assessment Area (EAA). Accordingly, EAA can be defined as “the entire area, sub-area, or 

point of an occurrence of a wetland type.” The level of inference may be about both wetlands overall 

and particular wetland types or wetland areas, but the analyses may be more complicated by the use of 

strata. 

Regardless of the option chosen, there are multiple strategies for sampling the point or the occurrence: 

1) conduct an assessment survey of the entire area of the occurrence (e.g., using a rapid qualitative 

assessment); 2) conduct an assessment survey of a typical sub-area(s) of the occurrence; or 3) collect 

data at a point (with specified radius) using one or more plots, placed in representative or unbiased 

locations. In all three cases, the intent is to assess the ecological integrity of a particular wetland 

occurrence. 

Here, we discuss our methods using the third option (above), identifying particular wetland types within 

a wetland, and surveying the entire area of that wetland type within a particular wetland (i.e., a wetland 

occurrence);. The goal is to assess the integrity of this occurrence, irrespective of the property or 

management regime it may be found on, or its size. Note however that these methods can be easily 

adapted to the first option above1

. 

 

1

 When combining a rapid assessment approach with an intensive approach, one method of sampling would be select points 

for monitoring, then use a 0.5 ha area around the point (equivalent to the EAA) for the rapid assessment (Jacobs 2003). To 

conduct an intensive assessment, a single 0.1 ha plot, with 4 or more subplots, could be used. Not all points may need 

intensive plots, reducing the cost of monitoring. 
42

Some Guidelines for Field Methods 

Six basic guidelines are provided below for conducting wetland assessments (from Faber-Langendoen et 

al. 2008a): 

1) Determine where the occurrences of a wetland type are and classify them using the UNSNVC. 

Wetlands will be classified using the U.S. National Vegetation Classification (FGDC 2008), as 

well as using Ecological Systems (Comer et al. 2003) (see Table 1). Knowing the Formation and 

System will determine which metrics are used and the rating scheme for the metrics, in so far as 

these vary by formation. For example, assessing the Buffer metric of a freshwater marsh found 

along a river corridor requires a different form of the metric than for marshes found in 

depressions. 

2) The field data collection protocols should be fairly standard, regardless of the intent of the 

survey, since the fundamental metrics of the IEI need to be included. Protocols for how to 

measure the metrics are briefly described in “Rapid Field Metrics”. This documentation will help 

inform the field data collection protocols. In many cases the metrics can be documented from 

remote sensing/aerial photo imagery; in other cases, by walking an assessment area, (either the 

site or a fixed area); and recording qualitative or relatively simple semi-quantitative or 

quantitiatve measures (Jacobs 2003, Fennessey et al. 2007). 

3) A field crew (two people) should be able to complete a rapid field assessment within two hours, 

plus two hours preparation time assessing the imagery (see #4 below). Once the crew leaves the 

field, the field forms are essentially complete. 

Field crew expertise should be akin to that needed for wetland delineation. In other words, field 

crews should have some knowledge of hydrology, soils, and vegetation sufficient to assess 

hydrologic dynamics, perhaps examine a soil core for mottling, and be able to identify all 

prominent exotic species in a region. 

4) Many of the metrics can be assessed, at least preliminarily, in the office using remote sensing 

imagery. Many other additional sources of information can help determine the condition and 

threats to a site (see Rocchio 2007) including Digital Orthophoto Quadrangles (1 m resolution), 

GIS layers (e.g., roads, utility lines, trails, mines, wilderness areas, National Land Cover Dataset, 

irrigation, ditches, groundwater wells, etc.), element occurrence records from Natural Heritage 

Programs, state or federal agency surveys, soils maps. 

5) Vegetation plots can be subjectively or objectively placed within the EAA to maximize 

abiotic/biotic heterogeneity within the plot. Capturing heterogeneity within the plot ensures 

adequate representation of local, micro-variations produced by such things as hummocks, water 

tracks, side-channels, pools, wetland edge, micro-topography, etc. in the floristic data. Plots can 

also be placed objectively, if enough plots are laid. 

6) It is usually helpful to map the extent of the occurrence as part of the field survey (see Rocchio 

2007), using the following steps (though the NPS vegetation maps may already provide this info, 

and field crews would be verifying the accuracy of the maps): 

i. Estimation of Wetland Boundaries. The first step is to map the wetland area. Readily 

observable ecological criteria such as vegetation, soil, and hydrological characteristics are 
43

used to define wetland boundaries, regardless of whether they meet jurisdictional criteria 

for wetlands regulated under the Clean Water Act. 

ii. Delineating Formation and Ecological System Boundaries. The second step is to delineate 

the targeted type present within the wetland boundary. Formation and Ecological System 

descriptions can be used to guide the delineation of the type boundaries in the field. 

Minimum map size criteria should be specified, and each patch of wetland type would be 

considered separate potential EAA or sub-EAA. If a patch is less than the minimum map 

size then it would be considered to be associated with internal variation of the type in 

which it is embedded. 

i. Size and Land Use Related Boundaries. Once the targeted type boundaries are delineated, 

then size and land use can be used to further refine EAA boundaries. For example, 

depending on the size or variation of the wetland area, the EAA may consist of the entire 

site or only a portion of the wetland/riparian area. For small wetlands, or those with a 

clearly defined boundary (e.g., isolated fens or wet meadows), this boundary is almost 

always the entire wetland. In very large wetlands or extensive and contiguous riparian 

types, a sub-sample of the area can be defined as the EAA for the project. For other project 

purposes such as regulatory wetland projects, there may be multiple EAAs in one large 

wetland. 

Significant change in management or land use may result in distinct ecological differences. Some 

examples follow: 

1) A heavily grazed wetland on one side of a fence line and ungrazed wetland on the other would 

result in two subunits of EAAs. 

2) Natural changes in hydrology could also be the basis for a separate assessment. For example, a 

drastic change in water table levels or fluctuations, confluence with a tributary, etc. would dictate 

at least a separate set of sub-EAAs. 

3) Anthropogenic changes in hydrology. For example, ditches, water diversions, irrigation inputs, 

roadbeds, etc. that substantially alter a site’s hydrology relative to adjacent areas would dictate at 

least a separate set of sub-EAAs. 
44

Figure 3. Example of Delineated Ecological Assessment Areas (EAAs). Although contiguous with each 

other, the fen and the riparian shrubland were delineated as distinct EAAs because either they were 

distinct ecological system types (e.g. fen vs. riparian shrubland). The fen was divided into sub-EAAs 

due to a human-induced disturbance (e.g., ditch) which significantly altered a large portion of an 

otherwise contiguous wetland type (e.g., intact vs. disturbed fen). Adapted from Rocchio 2007. 

4

0 70 140 210 280 35

Meters

Plot 25 – Intact Fen

Plot 25 – Sub AA Intact Fen

Plot 26 - Disturbed Fen

Plot 26 – Sub AA Disturbed Fen

Plot 27 - Riparian Shrubland

Plot 27 - Assessment Area

óóóóóóóóóóóóóóóóóóóóóóóóóóóóó

Full AA - Fen

Groundwater Flow 

Stream Flow 

Ditch 

Fence 
45

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49

Rapid Field Metric Descriptions 

Detailed descriptions are avalible for each metric in Faber-Langendoen et al. (2008a, Appendices), on 

the NatureServe website (www.natureserve.org). Note that a full set of protocols including plot design 

layout, sampling design, data management, etc. are beyond the scope of this report. Instead the 

descriptions for the metrics provide a foundation for a comprehensive protocol. 

51

Appendix A. Field Form RequirementsExample Field Form Biotic Composition—Vegetation Form Table A.1. Field information needed to evaluate Vegetation Structure and Vegetation Composition. Layer Total Cover (%) Exotic Cover (%) Height*(m) Most abundant species, and % cover of each (e.g., Acer rubrum (60%), etc.). In each layer, l

all species or surfaces greater than 5%, including unknowns. If tree layer, list ALL species. 

Tree Layer Shrub Layer Sapling Layer Herb/Field Layer Non-vascular Layer (Moss, Lichen, Alga) Floating/Submerged Layer Unvegetated Surface Coarse Woody Debris List # of large fallen stems by size classes in column to the right. Note # large stems > 30 cm 

advanced** stages of decay:_______ 

*Height is the predominant height of the main canopy, not of the tallest emergent. **Advance decay = 

53

Appendix B. Template for Metric Description

Metric A 

Definition:

Background:

Metric Type: 

Tier: 

Rationale for Selection of the Variable:

Measurement Protocol: 

Metric Rating: Specify the narrative and numerical ratings for the metric, from excellent to poor. 

Metric Rating 

Excellent Good Fair Poor 

 

Data: 

Scaling Rationale: 

Confidence that reasonable logic and/or data support the index: 

55

Appendix C. Draft Set of Intensive Metrics for NETN Wetlands 

In the course of compiling a rapid, level 2 assessment protocol, a number of intensive metrics were 

identified that may be relevant to a wide variety of wetlands in NETN. These could be considered along 

with the intensive metrics identified by Neckles et al. (2007) for assessing wet meadows and alkaline 

fens. Below are examples of such metrics. 

 

Vegetation Metrics 

Floristic Quality Assessment (Mean C) 

Definition: The mean conservatism of all the native species growing in the wetland. 

Background: This metric is one aspect of the condition of specific occurrences of wetland or terrestrial 

ecological systems. 

Metric Type: Condition 

Tier: 3 (intensive field method) 

Rationale for Selection of the Variable: Plants grow in habitats in which they are adapted to, including 

biotic and abiotic fluctuations associated with that habitat (Wilhelm and Masters 1995). However, when 

disturbances to that habitat exceed the natural range of variation (e.g. many human-induced 

disturbances), only those plants with wide ecological tolerance will survive and conservative species 

(e.g. those species with strong fidelity to habitat integrity) will decline or disappear according to the 

degree of human disturbance (Wilhelm and Masters 1995). 

These observations can be combined into a “conservatism” (or C) index, whereby species with strong 

fidelity to habitat integrity are scored 10 and those with a very low integrity are scored 1. Exotics are 

either scored 0 or excluded. The average C value (xC) is then multiplied by the square root of site or 

total plot (or native) richness (√S) to produce the Floristic Quality Assessment Index (FQA) index, (also 

called the Floristic Quality Index, or FQI). The FQA index, originally developed for the Chicago region 

(Swink and Wilhelm 1979, 1994) is a plant community index designed to assess the degree of 

"naturalness" of an area based on the presence of species whose ecological tolerance are limited. FQA 

methods have been developed and successfully tested in Illinois (Swink and Wilhelm 1979), Missouri 

(Ladd 1993), Ohio (Andreas and Lichvar 1995), southern Ontario (Oldham et al. 1995), Michigan 

(Herman et al. 1996), Indiana (Coffee Creek Watershed Conservancy 2001), and North Dakota 

(Northern Great Plains Floristic Quality Assessment Panel 2001), but the exact form of the equation is 

still debated. Various authors have criticized the approach of combining the C value with the square root 

of richness (Bowles and Jones 2006), and recommend treating each separately, as done here. 

Measurement Protocol: Species presence/absence data need to be collected from the wetland. Although 

quantitative measurements are preferred, depending on time and financial constraints, this metric can be 

measured with qualitative or quantitative data. The two methods are described as follows: (1) Site 

Survey (semi-quantitative): walk the entire occurrence of the wetland system and make notes of each 

species encountered. A thorough search of each macro- and micro-habitat is required. (2) Quantitative 

Plot Data: The plot method described by Peet et al. (1998) is recommended for collecting quantitative 

data for this metric. This method uses a 20 x 50 m plot which is typically established in a 2 x 5 
56

arrangement of 10 x 10 m modules. However, the array of modules can be rearranged or reduced to meet 

site conditions (e.g., 1 x 5 for linear areas or 2 x 2 for small, circular sites). The method is suitable for 

most types of vegetation, provides information on species composition across spatial scales, is flexible 

in intensity and effort, and compatible with data from other sampling methods (Peet et al. 1998, Mack 

2004). 

The metric is calculated by referencing only native species C value from a given state FQA Database, 

summing the C value, and dividing by the total number of native species (Mean C). 

The Mean C is then used to determine the metric status in the scorecard. 

Metric Rating: Specify the narrative and numerical ratings for a metric, from Excellent to Poor. 

Metric Rating 

Excellent Good Fair Poor 

> 4.5 3.5-4.5 3.0 – 3.5 < 3.0 

Data: Various state and provincial FQA Databases (in development) 

Scaling Rationale: In the Midwest, field studies using FQA have determined that a site with a Mean C 

of 3.0 or less is unlikely to achieve higher C values, thus this value was used as the Restoration 

Threshold (between Fair and Poor) (Wilhelm and Masters 1995). In other words, those sites have been 

disturbed to the degree that conservative species are no longer able to survive and or compete with the 

less conservative species as a result of the changes to the soil and or hydrological processes on site. Sites 

with a Mean C of 3.5 or higher are considered to have at least marginal quality or integrity, thus this 

value was used as the Minimum Integrity Threshold (between Good and Fair) (Wilhelm and Masters 

1995). The threshold between Excellent and Good was assigned based on best scientific judgment upon 

reviewing the FQA literature. As the FQA is applied in this region, the thresholds may change.

Confidence that reasonable logic and/or data support the index: High 

Vegetation Index of Biotic Integrity 

Rather than being a specific metric, the Vegetation Index of Biotic Integrity draws on a series of 

measures of vegetation, including the floristic quality index, to assess Biotic Integrity. A number of field 

studies have been conducted in which a Vegetation Index of Biotic Integrity (VIBI) was developed (e.g., 

DeKeyser et al. 2003, Mack 2004, Miller et al. 2006, Rocchio 2007). A VIBI can be developed that 

either serves as an indicator of all ecological attributes, or, if other metrics are developed for hydrology 

and soils, it serves as an indicator of the biotic attribute of the wetland. In addition, other biotic 

components, such as amphibians or macroinvertebrates, could be measured separately. Further details on 

the measure protocols are best described in Mack (2004). 

Hydrological Metrics 

Index of Hydrological Alteration 

Definition: This metric uses daily streamflow data to determine trends at one site or determine 

differences between pre- and post-impacts of sites. 
57

Background: This metric is one aspect of the condition of specific occurrences of wetland or terrestrial 

ecological systems. 

Metric Type: Condition 

Tier: 3 (intensive field method) 

Rationale for Selection of the Variable: The Index of Hydrological Alteration (IHA) is a readily 

available tool for calculating the characteristics of natural and altered hydrologic regimes using any type 

of daily hydrologic data, such as streamflows, river stages, ground water levels, etc. Rather than review 

the entire method here, please refer to http://www.freshwaters.org/tools to download the IHA software 

as well as supporting documentation, including numerous published papers. 

Measurement Protocol: Long-term daily streamflow data are required for this metric. If those are not 

available daily flow data may be generated using a hydrologic model or other simulation method (see 

Richter et al. 1997). The IHA statistics will be meaningful only when calculated for a sufficiently long 

hydrologic record. The length of record necessary to obtain reliable comparisons is currently being 

researched, however it is recommended that at least twenty years of daily records be used (see Richter et 

al. 1997). 

Some lake level and ground water well data are also available from the USGS, but much of this type of 

data is collected and managed by other local governmental entities. 

Metric Rating: Specify the narrative and numerical ratings for a metric, from Excellent to Poor. 

Metric Rating 

Excellent Good Fair Poor 

No significant change 

from Reference 

Hydrographs 

Slight change from 

Reference Hydrographs 

Moderate change from 

Reference Hydrographs 

Large change from 

Reference Hydrographs 

Data: The websites listed below provide data on hydrological metrics. 

Index of Hydrologic Alteration Software and Supporting Documentation: 

http://www.nature.org/initiatives/freshwater/conservationtools/ 

U.S. Geological Survey Streamflow Data: http://water.usgs.gov/usa/nwis. (data can be imported directly 

in the IHA). 

The U.S. Forest Service, U.S. Bureau of Land Management, and local government agencies may have 

streamflow data for some of the streams located on the lands they manage. 

Scaling Rationale: The scaling is based on best scientific judgment of deviation from the reference 

standard. Additional research may suggest changes to the scaling criteria. 

Confidence that reasonable logic and/or data support the index: Medium/High. 
58

Physiochemical Metrics 

Bank Stability 

Definition: This metric assesses the stability and condition of the streambanks. 

Background: This metric is one aspect of the condition of specific occurrences of wetland or terrestrial 

ecological systems. 

Metric Type: Condition 

Tier: 3 (intensive field method) 

Rationale for Selection of the Variable: Unstable or eroding banks are often the results of local and/or 

upstream impacts associated with channel incision induced by over grazing and/or upstream alterations 

in the hydrological and/or sediment regimes. The local impact from eroding or unstable banks is 

typically a drop in the local water table along with a change in composition of plant species growing 

along the streambanks. 

Measurement Protocol: This metric is measured by walking along the streambanks in the riparian area 

and observing signs of eroding and unstable banks. These signs include crumbling, unvegetated banks, 

exposed tree roots, exposed soil, as well as species composition of streamside plants (Prichard et al. 

1998, Barbour et al. 1999). Stable streambanks are vegetated by native species that have extensive root 

masses (Alnus incana, Salix spp., Populus spp., Betula spp., Carex spp., Juncus spp., and some wetland 

grasses) (Prichard et al. 1998). In general, most plants with a Wetland Indicator Status of OBL (obligate) 

and FACW (facultative wetland) have root masses capable of stabilizing streambanks while most plants 

with FACU (facultative upland) or UPL (upland) do not (Reed 1988, Prichard et al. 1998). 

Each bank is evaluated separately then averaged to assign the metric rating. 

Metric Rating: Specify the narrative and numerical ratings for a metric, from Excellent to Poor. 

Metric Rating 

Excellent Good Fair Poor 

Banks stable; evidence of 

erosion or bank failure 

absent or minimal; < 5% 

of bank affected. 

Streambanks dominated 

 ( > 90% cover) by 

Stabilizing Plant Species 

(OBL & FACW) 

Mostly stable; infrequent, 

small areas of erosion 

mostly healed over. 5-

30% of bank in reach has 

areas of erosion. 

Streambanks have 75-

90% cover of Stabilizing 

Plant Species (OBL & 

FACW) 

Moderately unstable; 30-

60% of bank in reach has 

areas of erosion; high 

erosion potential during 

floods. 

Streambanks have 60-

75% cover of Stabilizing 

Plant Species (OBL & 

FACW) 

Unstable; many eroded 

areas; "raw". Areas 

frequent along straight 

sections and bends; 

obvious bank sloughing; 

60-100% of bank has 

erosional scars. 

Streambanks have < 60% 

cover of Stabilizing Plant 

Species (OBL & FACW) 

Data: 

Wetland Indicator Status: U.S. Fish and Wildlife Service, National Wetlands Inventory website: 

http://www.nwi.fws.gov/plants.htm or USDA PLANTS Database: http://plants.usda.gov/ 
59

The Colorado Floristic Quality Assessment Database will also have Wetland Indicator Status 

information. 

Scaling Rationale: The scaling is based on Barbour et al. (1999), Prichard et al. (1998), and best 

scientific judgment of deviation from the reference standard. Additional research may suggest changes 

to the scaling criteria. 

Confidence that reasonable logic and/or data support the index: Medium. 

Soil Organic Carbon 

Definition: This metric measures the amount of soil organic carbon present in the soil. 

Background: This metric is one aspect of the condition of specific occurrences of wetland or terrestrial 

ecological systems. 

Metric Type: Condition 

Tier: 3 (intensive, field-based) 

Rationale for Selection of the Variable: Soil organic matter or carbon generally refers to the organic 

fraction of the soil, including plant and animal residues at various stages of decomposition, as well as 

substances synthesized by the soil organisms (Neue 1984). Organic matter plays an extremely important 

role in the soil environment, including increasing water holding capacity, encouraging soil structure, 

plus it has a high cation exchange capacity and supplies essential nutrients (Brady 1990). 

Soil organic carbon is a strong metric of soil quality due to its sensitivity to environmental disturbance 

(NRC 2000 in Fennessy et al. 2004). Given that soil organic carbon contributes to critical hydrologic, 

biogeochemical, and physical processes, a reduction in soil organic carbon from reference conditions 

serves as a strong indicator of loss of soil quality. 

Measurement Protocol: Multiple soil pits should be dug in the wetland to a depth of at least 40 cm. If 

quantitative vegetation data are being collected, soil pits should be located within these plots to allow 

correlations with vegetation data. For example, if using the 20 x 50 m plots described by Peet et al. 

(1998), soil pits would be located within each of the intensive modules. At least five replicate soil 

samples should be taken within the top 10 cm of the soil surface in each pit. The replicates are mixed 

together as “one” sample from the site. Each soil sample should be placed in its own individual plastic 

bag, packed on ice, and sent to a laboratory for analysis of soil organic carbon. 

Metric Rating: Specify the narrative and numerical ratings for the metric, from excellent to poor. 

Metric Rating 

Excellent Good Fair Poor 

Soil C is equivalent to 

natural range of variability 

Soil C is nearly equivalent 

to natural range of 

variability 

Soil C is significantly lower 

than natural range of 

variability 

Soil C is significantly lower 

than natural range of 

variability 
60

Data: N/A 

Scaling Rationale: Reference soil organic carbon levels need to be established in undisturbed wetlands. 

Thereafter, the scaling is based on best scientific judgment and an assumed linear relationship of the 

amount of deviation from the reference standard to level of disturbance. If data are collected from 

wetlands across a disturbance gradient, quantitative criteria could be established. Alternatively, if 

“baseline” soil organic carbon levels are known (from “pre-impact” conditions or from adjacent 

unaltered sites) then this metric can be used to determine change of soil organic carbon with time. 

Confidence that reasonable logic and/or data support the index: Medium/High. 

Soil Bulk Density 

Definition: Soil bulk density is a ratio of the mass/volume of the soil. This metric is a measure of the 

compaction of the soil horizons. 

Background: This metric is one aspect of the condition of specific occurrences of wetland or terrestrial 

ecological systems. 

Rationale for Selection of the Variable: Bulk density is a measure of the weight of the soil divided by its 

volume and provides an indication of the level of compaction. Compaction can result from any activity 

which compresses soil particles, thereby increasing the weight to volume ratio. This can reduce the 

soil’s water holding capacity, infiltration rate, water movement through the soil, and limit plant growth 

by physically restricting root growth (NRCS 2001). Bulk density of organic soils are typically much less 

than those of mineral soils, however as decomposition increases and/or organic soils are compacted 

from human activity, bulk density of organic soils will increase. This has corresponding negative 

impacts on ecological processes such as water movement through the peat body, decomposition, and 

nutrient cycling. 

Measurement Protocol: Multiple soil pits should be dug in the wetland to a depth of at least 40 cm. If 

quantitative vegetation data are being collected, soil pits should be located within these plots to allow 

correlations with vegetation data. For example, if using the 20 x 50 m plots described by Peet et al. 

(1998), soil pits would be located and samples collected within each of the intensive modules. 

The samples are collected by taking a core sample within the top 15 cm of the soil. A cylinder of known 

volume should be used to collect samples. A PVC pipe of known dimensions will suffice. The cylinder 

is simply inserted into the soil profile, extracted, then shaved to eliminate any soil which is not 

contained within the cylinder. The soil remaining in the cylinder can then be placed into a plastic bag 

and then sent to a laboratory for analysis. Bulk density and soil texture (e.g., particle distribution) should 

be analyzed. Alternatively, texture can be determined in the field using the “field hand method;” 

however, lab analysis is preferable. 

Once texture and bulk density are determined, use the information below to determine whether the soil’s 

bulk density is less than, equal to, or greater then the minimum root-restricting bulk density values listed 

for the corresponding texture of the soil and assign the metric rating accordingly in the scorecard. 
61

There are no root restricting values given for organic soils, thus if the wetland is dominated by organic 

soil, reference bulk density measurements need to be established in undisturbed areas. 

Metric Rating: Specify the narrative and numerical ratings for the metric, from excellent to poor. 

Metric Rating

Excellent Good Fair Poor 

Bulk density value for 

wetland is at least 0.2 

(g/cm3) less than Root 

Restricting Bulk Density 

value for the soil texture 

found in the wetland. 

Bulk density value for 

wetland is at least 0.2 

(g/cm3) less than Root 

Restricting Bulk Density 

value for the soil texture 

found in the wetland. 

(same as Very Good) 

Bulk density for wetland is 

between 0.2 to 0.1 

(g/cm3) less than Root 

Restricting Bulk Density 

value for the soil texture 

found in the wetland. 

Bulk density for wetland is 

= or > than Root 

Restricting Bulk Density 

value for the soil texture 

found in the wetland. 

Data: The data below are derived from a Natural Resource Conservation Service, Soil Quality 

Information Sheet—Compaction which can be found online at: 

http://soils.usda.gov/sqi/publications/sqis.html, http://www.urbanext.uiuc.edu/soil/sq_info/RSQIS4.pdf, 

and http://soils.usda.gov/sqi/management/files/RSQIS4.pdf. 

Theses texture classes have the following Root Restricting Bulk Density values (g/cm3): 

1) Coarse, medium, and fine sand AND loamy sand other than loamy very fine sand = 1.8 g/cm3 

2) Very fine sand, loamy very find sand = 1.77 g/cm3 

3) Sandy loam = 1.75 g/cm3 

4) Loam, sandy clay loam = 1.7 g/cm3 

5) Clay loam = 1.65 g/cm3 

6) Sandy clay = 1.6 g/cm3 

7) Silt, silt loam = 1.55 g/cm3 

8) Silty clay loam = 1.5 g/cm3 

9) Silty clay = 1.45 g/cm3 

10) Clay = 1.4 g/cm3 

Scaling Rationale: The scaling is based on best scientific judgment and an assumed linear relationship 

of the amount of deviation from the reference standard to level of disturbance. However, no distinction 

was made between Excellent and Good as there is no information to suggest that threshold. Alternatively 

if “baseline” bulk density levels are known (from “pre-impact” conditions or from adjacent unaltered 

areas) then this metric can be used to determine change of bulk density with time. 

Confidence that reasonable logic and/or data support the index: Medium/High. 
62

References for Appendix C 

Andreas, B. K. and R. W. Lichvar. 1995. Floristic index for establishing assessment standards: A case 

study for northern Ohio. Technical Report WRP-DE-8, U.S. Army Corps of Engineer Waterways 

Experiment Station, Vicksburg, Mississippi. 

Barbour, M. T., J. Gerritsen, B. D. Snyder, and J. B. Stribling. 1999. Rapid bioassessment protocols for 

use in streams and rivers: periphyton, benthic macroinvertebrates and fish, 2nd Edition. EPA 841-B99-002. U.S. Environmental Protection Agency, Office of Water; Washington, D.C. 

Bowles, M. and M. Jones. 2006. Testing the efficacy of species richness and floristic quality assessment 

of quality, temporal change, and fire effects in tallgrass prairie natural areas. Natural Areas Journal 

26:17-30. 

Brady, N. C. 1990. The Nature and Properties of Soils. MacMillian Publishing, New York, New York. 

Coffee Creek Watershed Conservancy. 2001. 2001 monitoring reports. 

http://www.coffeecreekwc.org/ccwc/ccwcmission/monitoring_reports.htm Coffee Creek Watershed 

Conservancy, Chesterton, Indiana. 

DeKeyser, E. S., D. R. Kirby, and M. J. Ell. 2003. An index of plant community integrity: development 

of the methodology for assessing prairie wetland plant communities. Ecological Metrics 3:119-133. 

Dukes, J. S., and H. A. Mooney. 1999. Does global change increase the success of biological invaders? 

Trends in Evolution and Ecology 14:135-139. 

Ervin, G. N. B. D. Herman, J. T. Bried, and D. C. Holly. 2006. Evaluating non-native species and 

wetland indicator status as components of wetlands floristic assessment. Wetlands 26:1114-1129. 

Fennessy, M. S., J. J. Mack, A. Rokosch, M. Knapp, and M. Micacchion. 2004. Integrated Wetland 

Assessment Program. Part 5: Biogeochemical and Hydrological Investigations of Natural and 

Mitigation Wetlands. Ohio EPA Technical Report WET/2004-5. Ohio Environmental Protection 

Agency, Wetland Ecology Group, Division of Surface Water, Columbus, Ohio. 

Herman, K. D., L. A. Masters, M. R. Penskar, A. A. Reznicek, G. S. Wilhelm, and W. W. Brodowicz. 

1996. Floristic quality assessment with wetland categories and computer application programs for 

the State of Michigan. Michigan Department of Natural Resources, Wildlife Division, Natural 

Heritage Program. In partnership with U.S. Department of Agriculture Natural Resources 

Conservation Service, Rose Lake Plant Materials Center, Michigan 

Ladd, D. 1993. The Missouri floristic quality assessment system. The Nature Conservancy, St. Louis, 

Missouri. 

Lopez, R. D. and M. S. Fennessy. 2002. Testing the floristic quality assessment index as an indicator of 

wetland condition. Ecological Applications 12:487-497. 

Mack, J. J. 2004. Integrated Wetland Assessment Program. Part 4: Vegetation Index of Biotic Integrity 

(VIBI) and Tiered Aquatic Life Uses (TALUs) for Ohio wetlands. Ohio EPA Technical Report 
63

WET/2004-4. Ohio Environmental Protection Agency, W etland Ecology Group, Division of 

Surface Water, Columbus, Ohio. 

Miller, S. J. and D. H. Wardrop. 2006. Adapting the floristic quality assessment index to indicate 

anthropogenic disturbance in central Pennsylvania wetlands. Ecological Indicators 6:313-326. 

Miller, S. J., D. H. Wardrop, W. M. Mahaney, R. P. Brooks. 2006. A plant-based index of biological 

integrity (IBI) for headwater wetlands in central Pennsylvania. Ecological Indicators 6:290-312. 

Neckles, H. A., A. T. Gilbert, G. R. Guntenspergen, N. P. Danz, T. Hollenhorst, A. Little, J. Olker. 2007 

(in prep). Protocol for monitoring freshwater wetlands in National Parks of the Northeast Temperate 

Network. Prepared for the National Park Service. U.S. Department of the Interior. U.S. Geological 

Survey, Reston, Virginia. 

Neue, H. U. 1984. Organic Matter Dynamics in Wetland Soils. Wetland Soils: Characterization, 

Classification, and Utilization. International Rice Research Institute. Manila, Philippines. 

Northern Great Plains Floristic Quality Assessment Panel. 2001. Floristic quality assessment for plant 

communities of North Dakota, South Dakota (excluding the Black Hills), and adjacent grasslands. 

Northern Prairie Wildlife Research Center, Jamestown, North Dakota. 

Natural Resources Conservation Service (NRCS). 2001. Rangeland soil quality—compaction. Soil 

Quality Information Sheet, Rangeland Sheet 4. U.S. Department of Agriculture, Natural Resources 

Conservation Service (http://soils.usda.gov/sqi/publications/sqis.html). Accessed March 26, 2009. 

Oldham, M. J., W. D. Bakowsky, and D. A. Sutherland. 1995. Floristic quality assessment system for 

southern Ontario. Natural Heritage Information Centre, Ontario Ministry of Natural Resources, 

Peterborough, Ontario. 

Peet, R. K., T. R. Wentworth, and P. S. White. 1998. A flexible, multipurpose method for recording 

vegetation composition and structure. Castanea 63:262-274. 

Pimentel, D., S. McNair, J. Janecka, J. Wightman, C. Simmonds, C. O'Connell, E. Wong, L. Russell, J. 

Zern, T. Aquino, and T. Tsomondo. 2001. Economic and environmental threats of alien plant, 

animal, and microbe invasions. Agriculture, Ecosystems and Environment 84:1-20. 

Prichard, D., J. Anderson, C. Correll, J. Fogg, K. Gebhardt, R. Krapf, S. Leonard, B. Mitchell, and J. 

Stsitets. 1998. Riparian area management: a user’s guide to assessing proper functioning condition 

and the supporting science for lotic areas. Technical Reference 1737-15. Bureau of Land 

Management, U.S. Department of Interior, Denver, Colorao. 

Reed, P. B., Jr. 1988. National list of plant species that occur in wetlands: 1988 national summary. U.S. 

Fish & Wildlife Service. Biological Report 88 (24). 

Richter, B. D., J. V. Baumgartner, R. Wigington, and D. P. Braun. 1997. How much water does a river 

need? Freshwater Biology 37:231-249. 
64

Rocchio, J. 2006. Vegetation index of biotic integrity for southern rocky mountain fens, wet meadows, 

and riparian shrublands: Phase 1 Final Report. Unpublished report prepared for Colorado 

Department of Natural Resources, and U.S. Environmental Protection Agency, Region VIII. 

Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. 

Rocchio, J. 2007. Floristic quality assessment indices of Colorado plant communities. Unpublished 

report prepared for Colorado Department of Natural Resources, and U.S. Environmental Protection 

Agency, Region VIII. Colorado Natural Heritage Program, Colorado State University, Fort Collins, 

Colorado. 

Swink F. and G. Wilhelm. 1979. Plants of the Chicago Region. Revised and expanded edition with keys. 

The Morton Arboretum, Lisle, Illinois. 

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

Illinois. 

Taft, J. B., G. S. Wilhelm, D. M. Ladd, and L. A. Masters. 1997. Floristic quality assessment for 

vegetation in Illinois, a method for assessing vegetation integrity. Erigenia, Number 15, November 

1997. The Illinois Native Plant Society Journal. 

Taft, J. B., C. Hauser, and K. R. Robertson. 2006. Estimating floristic integrity in tallgrass prairie. 

Biological Conservation 131:42-51. 

Wilhelm, G. S. and L. A. Masters. 1995. Floristic Quality Assessment in the Chicago Region. The 

Morton Arboretum, Lisle, Illinois. 

Yorks, T. E., and S. Dabydeen. 1998. Modification of the Whittaker sampling technique to assess plant 

diversity in forested natural areas. Natural Areas Journal 18:185-189. 
65

Appendix D. Vegetation Field Sampling

Although plot-based or area-based measurements are preferred, depending on time and financial 

constraints, this metric can also be measured using plot-less techniques. The two methods are described 

as follows: (1) Site Survey (semi-quantitative): walk the entire occurrence of the community type at the 

site and make notes on vegetation strata, their cover, and exotic species. (2) Quantitative Plot Data: Use 

a fixed area method. A variety of techniques are available, including line transects, transects with 20 or 

more small 0.25 – 1 m2 quadrats laid along them, or fixed-area plot methods of 100 to 1000 m2. Studies 

by Yorks and Dabydeen (1998) and Rocchio (2006) found that the transect method did not pick up most 

non-dominant species and therefore was biased toward dominant species and resulted in biased 

proportions for some guilds (graminoids, forbs, low levels of exotics, etc.). This can result in metrics 

which are less sensitive to changes resulting from human disturbances. Thus, the plot (or reléve) method 

is preferred. 

The plot method may either be a “rapid plot” or a more intensive plot, following the 0.1 ha modular 

approach of Peet et al. (1998). The rapid plot incorporates some aspects of the intensive plot. For the 

rapid plot 1 or more 10 x 10 or 20 x 20 m plots may be systemically or randomly placed within the 

assessment area. 

The plot method described by Peet et al. (1998) is a recommended approach for collecting quantitative 

vegetation data. This method uses a 20 x 50 m plot which is typically established in a 2 x 5 arrangement 

of 10 x 10 m modules, and provides a standard 0.1 ha sample area, a widely used standard for assessing 

species richness. However, the array of modules can be rearranged or reduced to meet site conditions 

(e.g., 1 x 5 for linear areas or 2 x 2 for small, circular sites). Species presence and cover is recorded in 

each of four modules. If time permits, the reset of the 50 x 20 m area can be surveyed for additional 

species to obtain a 0.1 ha sample. The method is suitable for most types of vegetation, provides 

information on species composition across spatial scales, is flexible in intensity and effort, and 

compatible with data from other sampling methods (Peet et al. 1998, Mack 2004). 

References for Appendix D 

Mack, J. J. 2004. Integrated Wetland Assessment Program. Part 4: Vegetation Index of Biotic Integrity 

(VIBI) and Tiered Aquatic Life Uses (TALUs) for O hio wetlands. Ohio EPA Technical Report 

WET/2004-4. Ohio Environmental Protection Agency, W etland Ecology Group, Division of 

Surface Water, Columbus, Ohio. 

Peet, R. K., T. R. Wentworth, and P. S. White. 1998. A flexible, multipurpose method for recording 

vegetation composition and structure. Castanea 63:262-274. 

Rocchio, J. 2006. Vegetation index of biotic integrity for southern rocky mountain fens, wet meadows, 

and riparian shrublands: Phase 1 Final Report. Unpublished report prepared for Colorado 

Department of Natural Resources, and U.S. Environmental Protection Agency, Region VIII. 

Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. 

Yorks, T. E., and S. Dabydeen. 1998. Modification of the Whittaker sampling technique to assess plant 

diversity in forested natural areas. Natural Areas Journal 18:185-189. 

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