Northern Floodplain Forests

A floodplain forest is a wooded area located in or around a waterway or bottomland that is subject to periodic flooding. These floodplains can be narrow and steep, in the case of small mountain streams, or fairly wide and level, such as the area around the Monocacy or Potomac Rivers. A narrow floodplain around a small (1st or 2nd order) stream tends to have more intense, flashy water flows and the ground does not stay wet very long. A wider, more level flood plain, however, tends to have less dramatic flood events, but the soil retains the moisture longer. The variety of trees found in floodplains are those that can tolerate periods of waterlogged conditions; trees growing in a flat floodplain, much more so.

Floodplain forest (Middle creek)

Credit: - Jan Barrow

Some of the trees associated with smaller, upland floodplains are tulip poplar, beech, yellow birch, hazel alder, sycamore, green ash, sugar maple, hemlock, white pine, red maple, hackberry, elm, and hazelnut. Some of the more common trees in the larger floodplain forests include sycamore, green ash, boxelder, black willow, persimmon, river birch, honey locust, catalpa, silver maple, red maple, elm, and bald cypress.

By virtue of its location, the floodplain forest serves a very important ecological function. These forests enhance the environment by trapping sediment, nutrients, and pollutants before they can reach the water. Forest buffers also act like a big sponge, soaking up a lot of rain water before it can accumulate and contribute to flooding. The canopies of these forests chill water temperatures, which is very important for cool water fish, such as trout. The leaf litter, flowers, buds, sticks, and other material falling from these trees provides “detritus” to the stream, which aquatic organisms process for food. By doing this, these micro and macro invertebrates convert the energy and food that aquatic organisms need to survive. When large sections of trees fall into the stream, they provide “coarse woody debris,” or “structure” used for aquatic habitat.

Forested areas adjacent to wetlands also provide important wildlife habitat, since all animals need water. Many migratory birds also follow streams and rivers and nest in these forests. While most animals frequent these areas to drink water, there are a number of animals that are closely associated with floodplain forests such as beavers, muskrats, waterfowl, fox squirrel, mink, raccoon, weasels, and otters.

Article by FCFCDB member

Nature Note for 11/5/2017