West Gulf Coast Large River Floodplain Forest

This system represents a geographic subset of Kuchler's (1964) Southern Floodplain Forest found west of the Mississippi River. Examples may be found along large rivers of the West Gulf Coastal Plain and Upper West Gulf Coastal Plain, especially the Trinity, Neches, Sabine, and others. Several distinct plant communities can be recognized within this system that may be related to the array of different geomorphic features present within the floodplain. Some of the major geomorphic features associated with different community types include natural levees, point bars, meander scrolls, oxbows, and sloughs. Vegetation generally includes forests dominated by bottomland hardwood species and other trees tolerant of flooding, including bald-cypress and water tupelo. Some other trees which may be associated with examples of this system include Acer rubrum var. drummondii, Betula nigra, Carya aquatica, Celtis laevigata, Fraxinus pennsylvanica, Liquidambar styraciflua, Platanus occidentalis, Gleditsia aquatica, Nyssa aquatica, Nyssa biflora, Pinus taeda, Populus deltoides, Quercus laurifolia, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus pagoda, Quercus phellos, Quercus similis, Quercus texana, Salix nigra, Ulmus americana, and Ulmus crassifolia. Smaller areas of herbaceous- and shrub-dominated vegetation may also be present in certain areas. Shrubs and small trees include Alnus serrulata, Arundinaria gigantea, Carpinus caroliniana, Cephalanthus occidentalis, Clethra alnifolia, Cornus foemina, Crataegus viridis, Forestiera acuminata, Ilex decidua, Itea virginica, Morella cerifera, Planera aquatica, Sabal minor, and Ditrysinia fruticosa. Vines may include Berchemia scandens and Smilax bona-nox. Herbaceous species may include Boehmeria cylindrica, Carex complanata, Carex debilis, Carex intumescens, Carex joorii, Leersia virginica, Lycopus virginicus, Mikania scandens, Saccharum baldwinii, and Typha latifolia. Aquatic and floating herbs include Lemna minor, Nelumbo lutea, Nuphar advena, and Nymphaea odorata.

This system is typically represented by forests that vary relative to the flooding regime, which is often controlled by local topographic variation and proximity to a river. Swamps are typically represented by forests of Taxodium distichum, with other species such as Nyssa aquatica, Gleditsia aquatica, and Carya aquatica also present. Some semipermanently flooded sites may also be dominated by Planera aquatica. Floating aquatics, such as Lemna minor, Potamogeton spp., Ceratophyllum demersum, and Nymphaea odorata, may also be present at those sites. Quercus lyrata is characteristic of seasonally flooded bottomlands, but numerous other species are also important components of the canopy, including Taxodium distichum, Quercus phellos, Fraxinus pennsylvanica, Liquidambar styraciflua, Nyssa biflora, Fraxinus caroliniana, and Quercus similis. Commonly encountered, and sometimes dominant, species of temporarily flooded sites include Liquidambar styraciflua, Quercus nigra, and Fraxinus pennsylvanica. Numerous other species, such as Quercus laurifolia, Quercus michauxii, Quercus pagoda, Quercus phellos, Quercus texana, Celtis laevigata, Acer rubrum var. drummondii, Ulmus crassifolia, Ulmus americana, and Carya illinoinensis, may also be important components of the canopy. Platanus occidentalis, Populus deltoides, Betula nigra, and Salix nigra are more conspicuous as early-successional species along the riverfront. Understory and shrub cover is variable but is typically relatively low, particularly in more frequently flooded sites and sites with significant overstory canopy. The understory may have small individuals of the overstory, as well as species such as Alnus serrulata, Arundinaria gigantea, Carpinus caroliniana, Ilex decidua, Ilex opaca, Callicarpa americana, Crataegus viridis, Crataegus marshallii, Crataegus opaca, Styrax americanus, Ditrysinia fruticosa (= Sebastiania fruticosa), Sambucus nigra ssp. canadensis, Clethra alnifolia, Cornus foemina, Forestiera acuminata, Ilex decidua, Itea virginica, Morella cerifera, and/or Sabal minor. Where the overstory canopy is open, Planera aquatica, Cephalanthus occidentalis, or Forestiera acuminata may form dense stands. Woody vines that may be encountered include Berchemia scandens, Smilax bona-nox, Vitis rotundifolia, Toxicodendron radicans, and Campsis radicans. Herbaceous species may include Boehmeria cylindrica, Saururus cernuus, Saccharum baldwinii, Elymus virginicus, Onoclea sensibilis, Carex cherokeensis, Carex complanata, Carex intumescens, Carex joorii, Carex debilis, other Carex species, Chasmanthium latifolium, Chasmanthium sessiliflorum, Justicia ovata, Bidens aristosa, Panicum hemitomon, Leersia virginica, Lycopus virginicus, Mikania scandens, Saccharum baldwinii, Typha latifolia, and numerous others. Pinus taeda may be found, particularly on some better-drained sites and where it has been planted. Triadica sebifera sometimes invades this system. Aquatic and floating herbs include Lemna minor, Nelumbo lutea, Nuphar advena (= Nuphar lutea ssp. advena), and Nymphaea odorata.

Some of the major geomorphic features associated with different community types within this system include natural levees, point bars, meander scrolls, oxbows, and sloughs (Sharitz and Mitsch 1993). This system typically occupies Quaternary Alluvial geology along major rivers including the Trinity (downstream of Cobb Creek), Neches, Angelina, Sabine, Sulphur, and San Jacinto, and a few of their major tributaries. Landforms include broad floodplains with significant development of bottomland soils. These areas include an array of local geomorphic features such as natural levees, point bars, meander scrolls, oxbows, terraces, and sloughs. This system occupies soils of various textures derived from alluvial processes of the associated rivers. The hydrology of these soils is variable, including temporary, seasonal, and semipermanent flooding regimes.

This system occurs along large rivers of the West and Upper West Gulf coastal plains, especially the Trinity, Neches, Sabine, and others, as well as the portion of the Red River represented by Keys et al. (1995) (231Em) at the Oklahoma-Texas border.