Alaska’s landscape is loaded with shallow lakes and wetlands like these. NPS photo

By Bob Janiskee Scientists working in Denali National Park suspect that permafrost melting that’s caused by climate warming might be an important reason why many of Alaska’s shallow lakes and wetlands have shrunk or disappeared. If the trend continues, wetland-dependent wildlife might be severely impacted. … Bush pilots and others familiar with the black spruce muskeg and treeless tundra that blankets vast areas of interior and northern Alaska have long known that many shallow lakes, ponds, marshes, and other wetlands have shrunk in size or completely disappeared in the last half-century. This has puzzled them, as has the fact that many wetlands seem not to have changed at all. Whatever is going on, it doesn’t seem to be affecting all wetlands in the same way. … It seems that the shallow lakes and wetlands most prone to shrink or disappear in Denali are those that are underlain by sand and/or are partially rimmed by permafrost, the permanently frozen soil, organic matter, and ice that underlies vast areas of Alaska’s muskeg and tundra. The lakes and wetlands in this part of the world were formed about 8,000 years ago when the most recent glaciation ended, and many (but not all) owe their continued existence to the fact that permafrost helps to confine their water — sort of like the sides of a bathtub – and keeps it from draining way. The problem is, Alaska’s climate has warmed perceptibly in recent decades and much of the permafrost near the surface has melted or is close to doing so. Based on their research to date, Larsen and Berbyla are hypothesizing that warming temperatures are indirectly contributing to wetlands drying by breaching the permafrost containment of many shallow water bodies. … To read more about wetlands drying in Denali, visit this site.

Melting Permafrost May Help Explain Why Many Denali National Park Wetlands Are Drying Up via The Oil Drum