A wetland is an ecotone: the gradient between two different types of ecosystems. It is ecologically transitional between terrestrial and aquatic, with characteristics of each. So that’s an ecological definition.
However in the United States, we need a legal definition, because these ecosystems are protected by Federal law, and we need a way to draw a line around the system to know what we’re regulating. That legal definition is:
“Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.
Wetlands generally include swamps, marshes, bogs, and similar areas.”
…and that is included in the US Army Corps of Engineers 1987 delineation manual. It says, step-by-step, how to draw a line around a wetland (de-line-ation). Voila!
“But Paul,” you say…”how exactly does one determine whether a spot really would have saturated soil and support wetland vegetation?” Well friend, that’s no small task. And it takes considerable education and training to do that work. But don’t despair! Here at 99wetlands, I’ll help you navigate the ecology and regulation of wetlands, regaling you with thrilling tales of hydrophytic vegetation, field indicators of inundation, and probing those stinky, mucky soils! Yay wetlands!!