Prevalence index scores <3.0 typically indicate that the site has a dominant component of
hydrophytic vegetation, therefore representative of a wetland-type habitat (Peet et al., 1988, U.S.
In the Fall 2001 sampling period, 100% of the quadrats sampled in the reference wetland met
hydrophytic plant requirements (greater than 50% of the dominant species were FAC or wetter), while only 60% of those in the constructed wetland met the same requirements.
The relationship between mean C values of
hydrophytic vegetation and the level of hydrologic manipulation among all sites was not significant ([R.sup.2] = 0.002, P=0.80).
The water table remains close enough to the soil surface that the soil profile is nearly saturated or can become saturated for a sufficient time to allow
hydrophytic (water-tolerant) vegetation to survive.
The two criteria were considered sufficient because if
hydrophytic vegetation and hydric soils were present, then it was not necessary to show the hydrology criterion (Weibe et al.
The bog vegetation consists exclusively of mosses and
hydrophytic plants.
These are soils which are inundated with water long enough during the growing season to create an anaerobic soil condition which stimulates growth of
hydrophytic vegetation.
And instead of the
hydrophytic vascular plants normally found in wetlands, some wetland biota include primarily algae.
This is often associated with both increased productivity and a change in community composition to more
hydrophytic species (Oberbauer and Billings 1981, Isard 1986).
In the swampbuster provision of the 1985 Food Security Act, USDA defined wetland as soils formed under saturated conditions (hydric soils) that are undrained, inadequately drained, or seasonally wet long enough to support plants normally found in wetlands (
hydrophytic vegetation), even if the plants have been removed.
At best, one can plan, design, and construct for the fundamental wetland components: hydrology, hydric soils, and
hydrophytic plants; and basic stream morphology components: discharge, gradient, sinuosity, width/depth ratio, channel material and size, soil stability, channel entrenchment, and valley confinement.