Seasonal Wetland

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Wetlands occur where water saturates the ground for a period of time on a regular basis. Some of Arizona's most important wetlands are dry much of the year. However, even the temporary presence of standing water can foster flood-adapted plants and develop unique, productive soils. Plants, such as wetland sedges and Arsene's Buttercups, have co-evolved with seasonal wetlands. Wetland plants capture energy through photosynthesis that is shared throughout the ecosystem with insects, birds, and other wildlife. Wetlands also cycle nutrients very effectively.

A wetland is a radiating habitat, which means it sustains ever-widening circles of different plants and animals. More than 80% of wildlife species in Arizona depend on a wetland or streamside habitat at some point during their life cycles. Yet wetlands are very rare in Arizona. A map created by the University of Arizona shows that wetlands now occupy less than 1% of the state and are mostly in the mountainous central region. 

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Wetlands are also important because they store floodwater and improve water quality. Did you notice that the Willow Bend parking lot is slightly slanted toward a culvert in its southeast corner? Rain and snowmelt flow through the culvert into the wetland, where flood-tolerant plants slow it down and allow suspended sediments to settle. Pollutants stick to soil particles; some are taken up by plants or transformed by microorganisms as the water percolates into the ground.

While a constructed wetland such as Willow Bend's is not as biodiverse as a natural one, nevertheless it sustains wildlife, captures floodwater, and improves water quality in its own small way. It also has educational value in countering a persistent view that wetlands are wastelands that should be drained and put to use.