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Ephemeral Wetlands

THURSDAY, 25 MARCH 2010


Ephemeral or seasonal wetlands are depressional wetlands that temporarily hold water in the spring and summer or after heavy rains. Even though seasonal wetlands are often isolated from other bodies of water, they are ideal breeding sites for many amphibian species. These wetlands are easily located by the numerous breeding calls emanating from these areas in the spring. Ephemeral or seasonal wetlands are characterized by their tendency to completely dry out most summers only to fill up again during the wet season. As a result, fish are usually absent, which allows amphibian populations to flourish with minimal predation.

Many species of reptiles and amphibians are highly dependent on ephemeral wetlands and do not occur in areas where these wetland type habitats are not available. The cyclical filling and drying of ephemeral wetlands, their shallow nature, and the abundant invertebrate prey base make these areas excellent breeding sites for numerous amphibian species. The tiger salamander, blue-spotted salamander, and the wood frog are examples of species that rely on ephemeral wetlands. Several members of the reptile community take advantage of seasonally abundant prey items found in and around these wetlands. For instance, the garter snake, common snapping turtle, and numerous mud turtle species are just a few examples of reptiles that utilize seasonal wetlands.

One critical feature of a healthy ephemeral wetland is the adjacent upland habitat. The surrounding upland habitats are used by reptiles and amphibians for activities such as hibernation and foraging. A buffer area of at least 500 feet wide above the high water mark is recommended as a minimum to provide refuge for many species. Undisturbed uplands are important because they connect isolated wetlands and serve as travel corridors that certain species use to get from one wetland to another. As seasonal wetlands dry out, corridors provide reptiles and amphibians with a means to access more permanent wetlands.

The management of ephemeral wetlands falls into two main categories: protection and restoration. Ephemeral wetlands can be restored but efforts to create them from scratch are usually unsuccessful. Some steps that can be taken to restore an ephemeral wetland include removing existing drainage tiles, filling drainage ditches, and removing fill dirt. These practices help return wetlands to near natural conditions. An integral part of wetland management is the maintenance of natural water-level fluctuation. This can be accomplished simply by protecting these wetland areas from tiling, excavating, and ditching, which would alter the water levels. Amphibians require a few months to change into adult form, so protecting these temporary wetlands is critical for their survival.

The identification and maintenance of ephemeral wetlands, critical surrounding habitat, and functional corridors between them are important steps towards the management and conservation of these habitats for reptiles and amphibians. Other wildlife species also benefit from habitats associated with ephemeral wetlands. Seasonal wetlands are important for a variety of bird species, including ducks, shorebirds, and songbirds. These areas are very important to many species of animals. Enjoy them when possible, and do your part to protect and preserve these unique wetlands for future generations. For more information, contact Little River Area Biologist Tracy L. Nelson at Tracy.Nelson@dcnr.alabama.gov.

The Alabama Department of Conservation and Natural Resources promotes wise stewardship, management and enjoyment of Alabama's natural resources through five divisions: Marine Police, Marine Resources, State Lands, State Parks, and Wildlife and Freshwater Fisheries. To learn more about ADCNR, visit www.outdooralabama.com.

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