Looking out across the expanse of the everglades, one may see small stands of trees. These occur in regions of depression within the marsh which results in a longer hydroperiod than sorrounding marsh areas. The principle constituent of these are Cypress trees, of which two species can be found in the everglades. The bald cypress and the pond cypress. These cypress may be hundreds of years old. The term, “cypress dome” or cypress head refers to the phenomenon that the larger cypress grow in the middle of the dome, and then get progressively smaller as one goes out from the center. The conditions for growth (long hydroperiod) are much better in the center as opposed to the edges.

The vast root system of a cypress tree produces growths that can protrude above the surface of the water or water-logged soil. These cypress knees may protrude above the water line in up to 4 feet of water and function in the “breathing” (oxygen consumption) of the roots. The soils where cypress grow are usually saturated with water and as a consequence are oxygen deficient. Roots require oxygen and thus the unique breathing “knees” are an important adaption of these trees. Also associated with the cypress are a large number of epiphytes, plants which grow on the tree itself. Some examples include bromeliads, orchids, and ferns. For epiphyte density observation, click here.

An interesting feature associated with some cypress domes is the occurence of a unique tree known as the pond apple. It grows best in areas with a long hydroperiod. It can be found in the middle regions of a cypress dome and does not grow much taller than 35 feet. It’s unique features include a large multi-trunked appearance, coupled with large buttress roots, and a complex branching pattern. Associated with the pond apple and the cypress are a large number of epiphytes which grow on the trees dark brown bark. Nesting birds such as the anhinga, can often be found nesting in the pond apple. As well, in the standing water of the cypress dome, one may see many small fish, leeches, and other small freshwater organisms. There are a small number of insects that can be observed in and throughout the trees. There are a number of other tree species sorrounding the cypress dome.

The cypress dome is of tremendous ecological value to the everglades in general. The trees provide nests for wading birds, and the long hydroperiod provides a perfect location for alligator holes. The impact of water level, fire, drainage, and decreasing alligator activity in some areas, has all resulted in major changes to tree islands and their distribution within the everglades.