Vernal pools are seasonal wetlands that occur in depressions in the landscape and are characterized by invertebrates (fairy shrimp and clam shrimp) and breeding amphibians (spotted, Jefferson and marbled salamanders and wood frog) that tend to be intolerant of fish. Vernal pools are known for often dramatic spring migrations of spotted and Jefferson salamanders, and early season choruses of breeding wood frogs.

Most of these habitats are at their fullest with water during the spring and hence the name: “vernal” pools. Some vernal pools fill in the fall and are referred to by some as autumnal pools. Marbled salamanders, in particular, are dependent on these autumnal pools because they mate and deposit eggs in late summer and early fall. When these pools fill with water in the autumn, the eggs hatch and the larvae live in the water beneath the ice throughout the winter. There is concern that changes in precipitation patterns resulting from climate change could have negative consequences for marbled salamanders and other species adapted to the particular hydrology of vernal pools.