A bog is a type of wetland, an area of land that is wet for most of the year. Wetlands are important for providing habitat for many different plants and animals. Peat bogs, like the one here at SHADOW are made up of acid-loving moss, including sphagnum moss. Sphagnum moss releases tannins and acids that leach into the lake and groundwater, creating a highly acidic environment.
Because the moss is so acidic, the organisms that help break down organic material like dead plants are not able to survive in the bog. This means that instead of rotting away quickly, fallen trees, twigs, and leaves break down very slowly over hundreds of years. Meanwhile, more moss grows to cover this decomposing plant material in a dense blanket.
Over hundreds of years, layers of moss-covered debris accumulate one on top of the other, creating rolling green mounds called hummocks as the moss accumulates at different rates. As more layers accumulate, older layers are compressed under their weight. This compression forms peat, nutrient-rich moss that is familiar to many people as potting mix for house plants.
Bogs are important for many reasons, one of which is their ability to absorb and filter water. The moss is like a sponge, absorbing many times its weight in water. By absorbing the water, it mitigates flooding and renews groundwater. Another critical function is the absorption of carbon dioxide. The slow decay process in a bog reduces the amount of carbon released from the forest as carbon dioxide.