Indicators of Wetlands All wetlands have three common characteristics: 1) wetland-type soils, 2) water, and 3) plants that can live in water and saturated soils. Army Corp of Engineers policy requires that at least one of each feature of the three characteristics must be present for an area to be identified as a “wetland.” Each of the characteristics is discussed below.
Photo credit: NESOIL.com
Soil—Soils that are characteristic of wetlands are called hydric soils. These soils are typically saturated with water for long periods of time during the growing season where the presence of oxygen is greatly reduced or absent (anoxic). Because the soils have reduced amounts of oxygen, changes in soil color (particularly gray or black), the presence of organic material, streaking of soil colors in shallow pits, and soil horizon development are all indicators of wetlands-type soils. Soils are typically called gleyed and often have mottling where reduction/oxidation reactions involving iron or manganese create spots or streaks of red in the gray-colored soil (see photo on right). A review of your county Natural Resources Conservation Service manual will identify most hydrictype soils in your area.
Photo credit: Ecosystem Research Group
Hydrology—Shallow groundwater at or very near the surface during the growing season can be considered a characteristic of wetlands. The water must be present for a sufficient period of time to influence the soils and types of plants within a wetland. Visual indicators of wetland hydrology include standing or flowing water, sediment deposits that may coat leaves or objects on the ground during seasonal flooding, rafted debris against trees, and observations of inundation. Plants—Indicator species of plants that are always found in wetlands are called obligate wetlands (99% of the time) or facultative wetlands (67-99%). Plants found in areas that are not typically wetlands are called facultative uplands or obligate uplands. While the above wetland characteristics provide a general guideline for identification of wetlands, you should consult with a qualified wetlands scientist to definitively identify and delineate the extent of wetlands using all three characteristics.
Photo Courtesy of WENCK
3 / North Dakota / Whiting’s Guide North Dakota Wetlands