A bayhead or baygall is a specific type of wetland or swamp habitat. The name baygall is derived from sweetbay magnolia and sweet gallberry holly. Baygalls are recognized as a discrete ecosystem by ecologist and the swamps have been described as "distinct wetland communities in the Natural Communities of Louisiana". Baygall swamps are most often found in the low laying margins of floodplains and bottomlands with little or poor drainage to the main creek, bayou, or river channel. Baygall or bayhead swamps found on slopes and hillsides are sometimes referred to as a forest seep or hanging bogs. Hanging bogs are typically found in hardwood-pine forests. Most baygall swamps are semi-permanently saturated, or flooded. The characteristics of a bayhead swamp are mostly broad, shallow drains, which can be found near margins of bottomlands and floodplains with little or no drainage. They most often receive a slow, but steady supply of water from seepage at the base of slopes and bluffs. Baygalls are relatively shallow wetlands, ranging from wet and saturated soils and leaf litter, to a few inches of stagnate or very slowly moving water, although some may occasionally be deeper depending on topography and rainfall. Most are also under closed or nearly closed canopies. Occasionally, larger and deeper baygalls may have open waterat the center with floating vegetation such as the fragrant water-lily. High acidity levels distinguish baygalls from other wetlands and they often support plant communities that are distinct form adjacent areas. Sphagnum is often associated with baygalls. Sometimes referred to as acid bog baygalls, baygalls typically have very high pH levels. Levels as high as 4.5 are not uncommon in the baygalls of the Big Thicket region of Southeast Texas, USA. The acidic waters that drain from baygalls can contribute significantly to blackwater rivers and creeks in the bottomlands. A baygall may be no more than a small pool or they can be a mile across. The Jack Gore Baygall Unit of the Big Thicket National Preserve at 12 square miles, is said to be is the largest in the world.
Flora
Baygalls are typically found in densely forested areas. Over-story trees associated with baygalls include baldcypress, swamp tupelo or swamp blackgum, red maple, green ash, laurel oak, water oak, sweetgum, and sweetbay. Longleaf pine are usually associated with hanging bogs or forest seeps. Understory species include smooth or hazel alder, swamp titi or leatherwood, sweet gallberry, American holly, Virginia willow or sweetspire, wax-myrtle, red bay, swamp redbay, bamboo-vine, poison sumac, possum-haw viburnum, muscadine grape. Ferns such as net-veined chain fern, sensitive fern, cinnamon fern, and royal fern may be found in the herbaceous layer. Several species of orchid are also associated with baygalls.
Species of conservation concern
The baygall swamps have around 20 animal species which are considered to be endangered or of conservation concern in various states and countries.
