"Large wetlands are beautiful and need to be protected, but for some animal species such as frogs, toads and salamanders, it is small wetlands that support greater species diversity," said Semlitsch, who along with his graduate research assistant, Russ Bodie, recently published their research in Conservation Biology. "These smaller, temporary wetlands--because they are dry at certain times during the year--are much harder to appreciate than vast marsh areas. But without these smaller wetlands, it is very possible that much of the animal and plant life that make wetlands rich, productive habitats would not survive. We need to worry about the conservation of smaller wetlands as well as the larger ones."

Small wetlands currently are defined as being less than 4 hectares, or about 8 to 9 acres. The majority of the nation's wetlands are much smaller than might be imagined, closer to 1 to 2 acres and sometimes as small as several square yards. These small wetlands may comprise the majority of wetlands in the United States and help support a vast diversity of wetland species. However, unlike the large wetlands, these smaller areas are not protected to the same extent.

Recently, the Army Corp of Engineers, which manages wetlands of all sizes throughout the United States, drafted regulations that will change the way wetlands are managed in the future. They have put off any change in management regulations until April, but the MU researchers argue that the changes in the regulations could manage these smaller wetlands out of existence.

"Right now we can't detect losses of small wetlands by satellite imagery, a technique used to assess environmental change," Bodie said. "We lose thousands of acres each year in wetlands and these smaller ones are not even taken into account. Yet, they play a vital role in the ecosystem and support a great variety of organisms."

Research done by Semlitsch and Bodie has indicated that when some individuals of a species move between wetlands, this increases their chances of survival. By populating many different wetlands, various species thrive, even during drought years when some wetlands are dry. When smaller wetlands are destroyed, the chances of survival for many species' populations may decrease dramatically because distances between individual wetlands become longer, making movement between wetlands more difficult. These small wetland breeding sites for amphibians are especially critical in light of purported world-wide declines, Semlitsch said.

Wetlands in general also have direct benefits to humans as they filter out chemicals and silt, buffer lands from flooding, and are a favorite of hunters and fishers. They also are very costly and difficult to develop for construction or other purposes.

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