What is a Vernal Pool?

Our current fundraising effort at Headwaters Science Center called Drop-by-Drop refers to "Vernal Pools" as part of the metaphor for levels of giving in relation to bodies of water. Some people are not familiar with this term and are asking for a definition.

So here goes.


A vernal pool is a type of temporary wetland formed each spring from snow-melt and spring showers. By early summer, after the frost is out and evaporation increases, vernal pools disappear. Some people refer to them as leaf-litter ponds, because in wooded areas the substrate under the water consists of decomposing leaves.

 And therein lies their little secret.

Fairy shrimp
(courtesy Vernal Pool Association)

A vernal pool is a great habitat for invertebrate life because of the nutrients released by rotting leaves and vegetation. Invertebrates such as fairy shrimp and mosquito larvae thrive in this aquatic environment providing a source of food for many animals that we are familiar with, such as salamanders and frogs that have an aquatic larval stage in their life cycle.

Fairy shrimp, mosquito larvae and other invertebrates provide an important source of protein for birds, such as mallards and wood ducks, as they begin their reproductive efforts - and the pools actually serve as courtship and mating areas for the breeding pairs although nesting and brood-rearing may occur at some distance. A host of other animals visit vernal pools for drinking water and to prey on the tadpoles, frogs and salamanders.

Vernal pools are often destroyed by draining and filling as development of forested areas occurs. Timber harvest opens the canopy, raising temperature and increasing evaporation, and the pools dry up much earlier compared to those in an uncut forest.

So our metaphor is complete. Vernal pools are small and to some people insignificant, but they have an important role to play in forest ecology.  Likewise, a donation of a small amount of money to Headwaters Science Center may seem insignificant, but can make a huge difference when combined with other small donations. Even a single drop of water can make big things happen when combined with many other drops!

Please visit our donation page, choose a level of giving and make your donation on Give to the Max Day November 14th.