Vernal Pools

Vernal Pools are a type of wetland that is usually associated with forest settings. Vernal Pools are ephemeral wetlands that are seasonally flooded and generally isolated from stream systems. These pools become dry annually, or at regular intervals and are generally absent of fish. Vernal pools are fed by rain, fill with water in late fall and remain wet until mid-summer before drying up. Not only are vernal pools wet for a small portion of the year, but they also tend to be extremely small, usually only fragments of an acre in size.

Sometimes called woodland pools, these wetlands provide a unique habitat that supports a diverse collection of organisms. Most of these organisms rely solely on this habitat for their life cycles. Although ephemeral wetlands are frequently overlooked in the regulatory arena, these special types of habitat provide a multitude of benefits that are necessary to a healthy functioning forest ecosystem.

Vernal Pool Examples

The Susquehanna River Watershed has vernal pools that can be found on all parts of the landscape. They tend to fall into two categories, natural and man-made. The natural pools are natural depressions in the headwater forests for our watersheds. Others are found in the floodplain forests along larger streams and rivers. The man-made types are either designed and built to function as a natural depression or created for another purpose. In many parts of the watershed, we have abandoned pasture ponds that have evolved into habitats that support vernal pool species. Below are examples of the pools in the watershed.

Vernal Pool Life

Organisms that are associated with vernal pools fall into two categories. Obligate or direct indicator vernal pool species are completely dependent on vernal pools for parts of their life cycles. They require this type of habitat in order to successfully breed and survive. If they are present then the habitat is classified as a vernal pool. Facultative or indirect indicator species are not solely dependent on vernal pools but are commonly found in and around them though they will also use other wetland habitats for their various life cycles.

Obligate Vernal Pool Species

Spotted Salamander
Jefferson Salamander
Blue Spotted Salamander
Wood Frog
Fairy Shrimp

Faculative Species

Red Spotted Newt
Northern Spring Salamander
Four-toed Salamander
Spring Peeper
Gray Tree Frog
American Toad
Green Frog
Leopard Frog
Pickerel Frog

For pictures of some of our local species visit Our Field Guide or CalPhotos amphibians page which hosts photos of amphibians from throughout the world.