Students in the AP environmental science course at Wayne Trace High School learned about the importance of wetlands along with the different types there are, along with their functions. This program featured a demonstration of the wetlands enviroscape model that gave students a powerful visual on the various types of wetlands that exist, along with the important function that each serves to the overall ecosystem. Before going into a demonstration of the model, students were given some background information on wetlands.
Wetlands are typically areas that are wet or at least saturated for a majority of the year. Other terms that individuals might have heard of with wetlands are swamp or marshes, which all mean the same thing. It is possible for wetlands to be dry at certain points of the year. It is important to know that not all wetlands are going to be the same from one area to the next. This has to do with the climate of the area that is going to allow for certain types of animals and plants to function given a certain set of conditions.
Wetlands form when the ground in a given area lies below the water table, which is the point that water is found below the soil surface. When this occurs, water will pool above the soil. We know it is a wetland when considering three factors: hydrology, hydric soils, and hydrophytic plants. The hydrology of a wetland is the saturated or flooded soils for a majority of the year. Hydric soils are those which are saturated with water and have a dark black appearance and low levels of oxygen. Hydrophytic plants are those which can survive in flooded environments and soils with low oxygen levels such as lily pads.
Students learned that wetlands are good for the environment for a wide variety of reasons. Some benefits include: flood control, trapping sediment, pollution filtration, wildlife habitat, along with food and fuel for humans.
To help students understand the importance of restoring the functions and values of wetlands, we simulated what our environment would be like without wetlands. Most unplanned land development occurred before humans understood the importance of wetlands, vegetation and sustainability.
We first identified sources of potential pollution in the average environment and used various items to represent the pollution. First, the storm drain was discussed. Storm drain systems help to keep flooding to a minimum during heavy rainfall events with the catch being that this water is not filtered out before it is discharged back into the nearest water source known as sludge, represented by a liquid cocoa mixture. Discharge pipes from factories becomes an issue. Soil erosion, represented by cocoa powder, happens all around us with excess soil erosion taking place when agricultural, construction, or forestry practices remove vegetation holding the soil in place.
Pesticides and fertilizers, represented by red and green drink mix, also prove to be issues with the overuse or improper application. When these chemicals are applied on frozen ground or prior to a rainstorm, the potential for runoff increases. Plants can use the fertilizer on the land, but when it enters the water, it now becomes a pollutant. Vehicles are an issue when it comes to oil and gas residue, represented by a liquid cocoa mixture.
Students learned about the various types of wetlands that are found throughout our environment and how they are beneficial. Sponges were used to represent each wetland type as wetlands act like sponges to soak up and filter toxins along with acting as a mechanism for flood control. Riparian wetlands occur on riverbanks and provide a vegetative barrier between upland uses and the waterway and includes vegetation such as trees, shrubs, or grasses. Riverine wetlands are found within the channel of moving water and are permanently flooded with vegetation consisting of floating plants such as lily pads that help to slow the rate of flowing water.
Farm wetlands serve as a transition zone between a farm field and water sources to act as a natural filter for erosion and runoff from the farm field. Farm wetlands help trap topsoil and nutrients (fertilizers) and pesticides used by the farmer. Each of the above wetlands were set in place across the model with the same pollution scenario being run. With this second simulation, students were able to see how the wetlands acted as sponges, trapping the pollutants and filtering out the water before it was discharged back into the environment.
Contact the Paulding Soil & Water Conservation District at 419-399-4771 for more information on this program.