Wetlands

by

Molly McGraw

• LAST REVIEWED: 01 December 2017
• LAST MODIFIED: 31 August 2015
• DOI: 10.1093/obo/9780199874002-0016

Introduction

Wetlands are a broad category of natural habitats that occupy almost all of the world’s biomes. Wetlands can be found from the high Arctic to tropical rainforests and from alpine elevations to areas below sea level. Wetlands may be freshwater, saltwater, or somewhere in between. They are prime habitat for waterfowl, but they may also host species as varied as the American alligator (Alligator mississippiensis), platypus (Ornithorhynchus anatinus), and freshwater crawfish (family Astacidae in the Northern Hemisphere and families Parastacidae and Austroastracidae in the Southern Hemisphere). Although there are a large variety of wetlands, they all are essentially wet habitats either with standing water (i.e., present year round) or intermittent saturation. Whatever the situation, water inundation influences the soil development and the type of vegetation present. Worldwide wetlands are under increasing pressure from sea-level rise associated with climate change, increasing human populations, and mineral extraction. Most of the world’s wetlands have been degraded and in some cases destroyed. Since the start of the environmental movement in the 1970s, there has been a push in applied wetland research in the area of wastewater treatment and soil remediation. Wetlands excel in both these areas. The economic value and protection of the world’s wetlands through the use of international organizations and governmental policy are also important areas in wetlands research. This article presents the major fields of wetlands research. The first part of the article is reference material. Here, major wetland and wetland-related organizations are listed, which is followed by a list of the premier international academic journals that routinely publish wetland-related research. Also presented are the leading general and topical wetland reference books and textbooks; these books were written by leaders in their respective areas. The second half of the article presents selected academic papers organized into major fields of research: Biogeochemistry, Hydrology, Geography, Climate Change, Degradation, Restoration, Creation, Phytoremediation, Wastewater Treatment, Remote Sensing, Economics and Policy, and Mitigation. The selected papers are either groundbreaking or classic papers that are heavily cited or were written by scientists who have distinguished themselves as leaders in their field. Both general and in-depth papers are included in each of the fields.

General Overviews

The following entries were selected to give researchers and students a general background on the types, study, and economics/policy of wetlands. The National Wetlands Research Center is the premier wetlands research facility in the United States. The US Army Corps of Engineers (the US wetlands permitting agency) Wetlands Research Technology Center is focused on wetland identification, delineation, and permitting. Finally, the National Estuary Program sponsors research and education in the major estuaries of the United States. The selected papers are heavily cited and cover a variety of important topics. The significance of diversity in wetlands and size is discussed in Heck, et al. 2003 and Semlitsch and Bodie 1998. Tiner 1991 looks at the composition of aquatic vegetation in wetlands, and the concept of a global wetland database is presented in Lehner and Döll 2004.

• Heck, Kenneth L., Jr., G. Hays, and Robert J. Orth. “Critical Evaluation of the Nursery Role Hypothesis for Seagrass Meadows.” Marine Ecology Progress Series 253 (2003): 123–136.

  DOI: 10.3354/meps253123

  The article examines the relationship between seagrass beds and the profusion of juvenile finfish and shellfish both in the Northern and Southern Hemispheres. A good background on seagrass is given.

• Lehner, Bernhard, and Petra Döll. “Development and Validation of a Global Database of Lakes, Reservoirs and Wetlands.” Journal of Hydrology 296.1–4 (2004): 1–22.

  DOI: 10.1016/j.jhydrol.2004.03.028

  The authors create a new Global Lakes and Wetlands Database (GLWD) from existing maps, remotely sensed data, and existing databases. An excellent discussion on the extraction of information and the creation of the new database. Available online for purchase or by subscription.

• National Estuary Program.

  Run by the US Environmental Protection Agency, the National Estuary Program is a program that protects major estuaries in twenty-eight states. The program sponsors research, restoration, and educational programs in these estuaries.

• National Wetlands Research Center.

  The National Wetlands Research Center (NWRC) is the premier governmental wetlands research center in the United States. Overseen by the United States Geological Survey, the center is located in the heart of the south Louisiana wetlands. The NWRC concentrates its research efforts into three broad areas: ecosystems research, restoration, and spatial analyses.

• Semlitsch, Raymond D., and J. Russell Bodie. “Are Small, Isolated Wetlands Expendable?” Conservation Biology 12.5 (October 1998): 1129–1133.

  DOI: 10.1046/j.1523-1739.1998.98166.x

  Written in response to the US Army Corps of Engineers policy allowing the development of wetlands 1.4 hectares (ha) and larger, Semlitsch and Bodie’s article discusses the importance of small, isolated wetlands to the biodiversity of an area. The authors recommend the policy be revisited. Available online for purchase or by subscription.

• Tiner, Ralph W. “The Concept of a Hydrophyte for Wetland Identification: Individual Plants Adapt to Wet Environments.” BioScience 41.4 (April 1991): 236–247.

  DOI: 10.2307/1311413

  Tiner’s article emphasizes why, in many situations, the composition of plant communities should be used, in combination with soil analyses and hydrology, to identify and delineate wetlands. Available online by subscription.

• Wetlands Research Technology Center.

  The Wetlands Research Technology Center (WRTC) is part of the US Army Corps of Engineers (USACE) Water Research Center located in Vicksburg, Mississippi. The WRTC is engaged in all areas of wetlands research and serves as a liaison between the USACE and the public, providing training and user manuals on wetlands regulations, such as 404 permitting.