Ponds are bodies where freshwater collects due to being fed by streams or rivers. The water is still, meaning that it does not flow or have currents. It is also relatively shallow and small when compared to lakes.
Ponds are usually shallow bodies of freshwater that are no more than 7 feet deep. Because the sunlight reaches the bottom of a pond, plants often grow here as well as on the surface and sides. These underwater flora are considered submergent and include horntail and bladderwort plants. Emergent plants are tethered to the bottom with roots, but they also rise out of the water, growing flowers just above the surface. Emergent plants include cattails and reeds. Floating plants, such as lily pads, float on the surface of the pond and have no roots.
Ponds are considered either permanent or vernal. Vernal ponds are usually a result of snow melt and occur only in the spring. Although they are only temporary, they are an important aspect of the ecosystem, providing feeding and breeding grounds for various amphibian and insect species. Some algae species that thrive in vernal ponds burrow into the mud once the pond dries up, creating a hard shell that protects the algae until the next spring.