Wooded Wetland Magic: Where the Fairies and Frogs Roam
by Elle Bogle
Have you ever been walking in the woods and come across what appears to be a large, muddy puddle? Maybe you continued walking past it and didn’t give it a second thought; or maybe you heard a faint splash or croaking sound and glanced back in a moment of curiosity. Take a closer look and you will find these puddles aren’t puddles at all. They are the coral reefs of the deciduous forest called vernal pools. Brimming with life and energy, these forest floor habitats are extremely delicate yet extremely vibrant and diverse ecosystems.
So, what exactly are vernal pools? Vernal pools are seasonal wetlands of springtime magic. They fill with rain and ice and snow melt in early spring, but completely dry up by late summer. Also known ephemeral pools, they’re isolated from larger bodies of water, are relatively free of many plants, and do not contain fish. While they are never more than a few feet deep at most, and sometimes no larger than a large tabletop in size; a remarkable diversity of life abounds within them.
Vernal pools are critical habitat to several amphibian and invertebrate species which are solely dependent upon them for life cycle completion. Blue spotted salamanders, spotted salamanders, and wood frogs breed exclusively in vernal pools, returning to the same one year after year. Tiny invertebrates such as clam shrimp and fairy shrimp also rely on these pools. Many species of insects such as mayflies, caddisflies, dragonflies, different species of beetles, and more can be found in the shallow waters.
Due to the pools’ temporary nature, metamorphosis is a race against time. Salamanders and frogs lay their eggs in them while they’re full of water. Fairy shrimp lay their eggs in the leaf litter and mud at the bottom of the pool after it has dried for the season. Here they remain dormant until the following spring when they hatch in new waters. Amphibians must morph from larva to adult by growing legs and walking out, while insects must sprout their wings and fly out before the waters disappear.
Fallen leaves from the surrounding upland forest form the base of the vernal pool food chain. Coating this leaf litter is a microscopic layer of algae and other organisms that, not only digest and breakdown the leaves, but serve as a food source for herbivorous insects and a variety of crustaceans such as seed shrimp, fairy shrimp, copepods, and daphnia. In turn, salamander, frog, and carnivorous-insect larvae feed on the herbivores. So much more than mudpuddles! The next time you are walking in the woods and you spy one of these magical pools, maybe you will stop and spend some time with the wonderous creatures inhabiting them.