Vernal pools are unique and vulnerable kinds of wetlands. They are usually ephemeral (temporary) pools that fill with snow melt and spring run-off, then dry sometime during the summer. However, vernal pools also include pools that fill at other times of the year. Many of these pools are vital breeding habitat for certain amphibians and invertebrates such as wood frogs, spotted and blue spotted salamanders, and fairy shrimp. What makes vernal pools such excellent breeding habitat is the seasonal nature of the pools that excludes fish populations that would prey on the offspring. Vernal pools are not only used for reproduction. Other species such as spring peepers, gray tree frogs, and a number of bird species use pools for feeding and resting. These important wetlands are some of the most vulnerable because they are small, isolated, and often dry, therefore unrecognizable. They are easily destroyed, frequently because they small or are dry.

Vernal pools not only provide vital habitat for local plants and animals, they are also important features in the landscape. Think of pools as islands in a sea of upland forest. Groups of pools form stepping stones of hospitable habitat for wildlife that are dependent on wetlands to travel. Animals may skip over one pool to find a more suitable one nearby. If the wetland mosaic of pools within an upland community is altered, wildlife populations may be isolated and more vulnerable to changes in their surroundings.

 source:UMaine.edu