Wetlands : characteristics and boundaries / Committee on Characterization of Wetlands, Water Science and Technology Board, Board on Environmental Studies and Toxicology, Commission on Geoscsiences, Environment, and Resources, National Research Council.

Format:

Book

Contributor:

Lewis, William M., Jr., 1945-

National Research Council (U.S.). Committee on Characterization of Wetlands.

Language:

English

Subjects (All):

Wetlands.

Wetland ecology.

Wetland conservation--Government policy--United States.

Wetland conservation.

Physical Description:

1 online resource (328 p.)

Edition:

1st ed.

Place of Publication:

Washington, D.C. : National Academy Press, 1995.

Language Note:

English

Summary:

"Wetlands" has become a hot word in the current environmental debate. But what does it signify? In 1991, proposed changes in the legal definities of wetlands stirred controversy and focused attention on the scientific and economic aspects of their management. This volume explores how to define wetlands. The committee--whose members were drawn from academia, government, business, and the environmental community--builds a rational, scientific basis for delineating wetlands in the landscape and offers recommendations for further action. Wetlands also discusses the diverse hydrological and ecological functions of wetlands, and makes recommendations concerning so-called controversial areas such as permafrost wetlands, riparian ecosystems, irregularly flooded sites, and agricultural wetlands. It presents criteria for identifying wetlands and explores the problems of applying those criteria when there are seasonal changes in water levels. This comprehensive and practical volume will be of interest to environmental scientists and advocates, hydrologists, policymakers, regulators, faculty, researchers, and students of environmental studies.

Contents:

Wetlands

Copyright

Acknowledgments

Preface

Contents

Executive Summary

DEFINITIONS, FACTORS, CRITERIA, AND INDICATORS

WATER

SUBSTRATE

VEGETATION

COMBINATIONS OF INDICATORS FOR WATER, SOIL, AND VEGETATION

ESPECIALLY CONTROVERSIAL WETLANDS

REGIONALIZATION

MAPS, IMAGES, AND MODELING

REGULATORY PRACTICE

FUNCTIONAL ASSESSMENT

GENERAL CONCLUSIONS

1 Introduction and Background

PURPOSES OF THE NRC REPORT

Identification and Characterization

Identification of Functions and Values

Variations

Relationships of the Three Themes

PATH TO REGULATION

CURRENT CONTEXT FOR REGULATION

2 Ecology of Wetland Ecosystems

INTRODUCTION

THE NATURE OF WETLANDS

Hydrology as a Driving Force

Causes of Variation

Organic Matter

Natural Disturbance

Nutrient Transformation

WETLAND FUNCTIONS

Relationship to Value

Unique Functions

Landscape Perspective

Relationship to Biodiversity

Removal of Nutrients and Sediments

Wetlands as Hydrologic Features of Watersheds

NATURE OF BOUNDARIES WITH UPLANDS

CONCLUSIONS

RECOMMENDATION

3 Wetland Definitions: History and Scientific Basis

HISTORY OF TERMINOLOGY

Nineteenth-Century American Legislation

Swamp and Overflowed Lands Acts

Wildlife Refuge System

Rivers and Harbors Act

New Legal Status

Water Pollution Control Act Amendments of 1972

Judicial Interpretation of the 1972 Statute

EVOLUTION OF THE REGULATORY DEFINITIONS

1956 Fish and Wildlife Service Definition

1974 Wetland Inventory Project

1975 USACE Proposed Definition

1976 FWS Interim Classification

1977 USACE Definition

Clean Water Act of 1977

1979 Cowardin Report

Riverside Bayview Decision

FOOD SECURITY ACT

STATUS OF DEFINITIONS

1985 FSA Definition

1979 FWS Definition.

FRAME OF REFERENCE FOR REGULATORY DEFINITIONS

Reference Definition

Terminology: Parameters, Criteria, Indicators

Criteria and Indicators

APPLICATION OF DEFINITIONS

RECOMMENDATIONS

4 Wetland Delineation: Past and Current Practice

WETLAND DELINEATION: MOTIVATION AND PROCEDURE

Clean Water Act

The Food Security Act

FEDERAL AGENCY MANUALS BEFORE 1989

USACE Manual

EPA Manual

NFSAM

Attempts to Revise the Federal Manuals

COMPARING THE FEDERAL MANUALS

Hydrology

Hydrologic Evidence

Growing Season

Hydrophytic Vegetation

Wetland Plant Species

Determining Prevalence

Treatment of FAC Species and FACU-Dominated Wetlands

Hydric Soils

Special Situations: Disturbed Areas, Problem Areas, Exceptions

Differences Resulting from Application of the Manuals

5 Wetland Characterization: Water, Substrate, and Biota

HYDROLOGY

Nature of Wetland Hydrology

Need to Evaluate Wetland Hydrology

Hydrologic Criterion

Saturation in Relation to Water Table Depth

Duration of Saturation and the Growing Season

Effects of Soil Temperature on Development of Anaerobic Conditions

Definitions of Growing Season and Their Application to Wetlands

Biological Zero

Growing Season as Defined by the Frost-Free Period

Interaction of Duration Threshold with Length of Growing Season

Resolving the Problem of Growing Season

Frequency of Saturation

Critical Depth of Saturation

Interannual Variation

Overview of Hydrologic Thresholds

Direct Methods for Evaluating Hydrology

Indirect Methods for Evaluating Hydrology

SOILS

Concepts of Soil

Soil-Forming Processes in Wetlands

Accumulation of Organic Matter

Development of Anaerobic Conditions

Redoximorphic Features

Hydric Soils List

Use of Hydric Soils in Delineation.

Use of Soil Surveys

Field Indicators of Hydric Soils

Hydrophyte List

Definition of Hydrophyte

Development of the Hydrophyte List

Facultative Species and the Concept of Wetland Ecotypes

Determining Predominance Of Hydrophytic Vegetation

Measure of Dominance: The 50% Rule

Prevalence Index

Evaluation of Thresholds

Visible Adaptations as Indicators of Hydrophytic Vegetation

Treatment of Facultative Species

Vegetation and Hydrology

Vegetation and Soil Type

Use of Vegetation to Set Boundaries

OTHER INDICATORS OF THE SUBSTRATE AND BIOLOGICAL CRITERIA

COMBINING THE FACTORS

Necessity for Three Factors

Coincidence of Characteristic Hydrology, Soils, and Vegetation

Modified Approach to Evaluating Evidence

Primary Indicators

Hierarchical Approach

Future Delineation Manuals

6 Especially Controversial Wetlands

PERMAFROST WETLANDS

Relevance of Permafrost to Wetland Formation

Dynamics of Permafrost Wetlands

Regulation of Permafrost Wetlands

RIPARIAN ECOSYSTEMS

Support of Biodiversity

Current Regulation of Riparian Ecosystems

ISOLATED WETLANDS AND HEADWATERS

ESPECIALLY SHALLOW OR INTERMITTENTLY FLOODED WETLANDS

AGRICULTURAL WETLANDS

Functions of Agricultural Wetlands

Differential Regulation of Agricultural Wetlands

SITES ALTERED FOR NONAGRICULTURAL PURPOSES

Types of Alterations

Identification of Normal Conditions

Assessment of Altered Lands

Limitations of assessment Methods for Altered Sites

TRANSITIONAL ZONES

7 Regionalization

HIERARCHY OF REGIONAL VARIATION

Regional Variation in Hydrology

Regional Variation of Soils

Regional Variation of Plants

Regional Variation in Abundance of Wetlands

REGIONALIZATION SCHEMES.

Regional Classification Systems

CURRENT APPROACHES

Regionalization of Federal Agencies

Regional Lists of Hydrophytes and Soils

Hydrology and Growing Season

Regional Applicability of Current Delineation Methods

ADVANTAGES AND DISADVANTAGES OF REGIONALIZATION

RESEARCH TO SUPPORT REGIONALIZATION

Benchmark Wetlands

Validation of Modeling Experiments

Field Experiments on the Reliability of Wetland Indicators

IMPLEMENTATION OF REGIONALIZATION

8 Maps, Images, and Modeling in the Assessment of Wetlands

AERIAL PHOTOGRAPHY AND SATELLITE IMAGING

Detection of Standing Water

Other Factors

WETLAND DELINEATION UNDER THE FOOD SECURITY ACT

Determinations Before 1994

Determinations After 1994

NWI MAPPING

GEOGRAPHIC INFORMATION SYSTEMS

HYDROLOGIC MODELING

Mathematical Models to Assess Wetland Hydrology

Types of Mathematical Models

Model Selection and Application

Advantages and Disadvantages of Hydrologic Modeling

QUANTITATIVE ANALYSIS OF BOUNDARIES

Transect Data for Boundary Determination

Detection of Boundaries with Image Analysis

Scientific vs. Legal Boundaries

9 Regulation of Wetlands: Administrative Issues

CONSISTENCY AND RELIABILITY OF WETLAND DELINEATIONS

Multiple Agencies

Standards for Expertise, Training, and Certification

Verification of Delineations

Uniformity and the Exercise of Professional Judgment

Resource Regulation and Private Rights

Use of Flow Diagrams and Charts

10 Functional Assessment of Wetlands

FUNCTION AND VALUES OF WETLANDS

GENERAL REQUIREMENTS FOR FUNCTIONAL ASSESSMENT

METHODS OF FUNCTIONAL ASSESSMENT

FUTURE METHODS OF FUNCTIONAL ASSESSMENT.

Assessment Based on Hydrogeomorphic Classification and Reference Wetlands

Wetland Evaluation Under the National Food Security Act Manual

Relevance of Hydrologic Factors to Functional Assessment

RELEVANCE OF WETLAND ASSESSMENT TO 404 PERMIT APPLICATIONS

USE OF FUNCTIONAL ASSESSMENT IN WATERSHED PLANNING

Advanced Identification (ADID)

Special Area Management Plans

CONCLUSION

References

APPENDIXES

APPENDIX A Soil Taxonomy

SOIL NOMENCLATURE 101

SOIL MOISTURE REGIME

AQUIC CONDITIONS

Elements of Aquic Conditions

OTHER TERMS RELATED TO SOIL WETNESS

Natural Drainage Classes

Soil Inundation

REFERENCES

APPENDIX B Case Histories

CASE HISTORY 1

CASE HISTORY 2

CASE HISTORY 3

CASE HISTORY 4

CASE STUDY 5

APPENDIX C Glossary

APPENDIX D Committee on Wetlands Characterization Biographical Sketches

Index

OTHER RECENT REPORTS OF THE WATER SCIENCE AND TECHNOLOGY BOARD

OTHER RECENT REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY.

Notes:

William M. Lewis, Jr., chair.

Includes bibliographical references and index.

ISBN:

9786610211111

9780309176798

0309176794

9781280211119

1280211113

9780309587228

0309587220

9780585158815

0585158819

OCLC:

43477394