Southeastern Great Plains Floodplain Forest

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Nature Serve ID: CES205.710

Geology

This system generally occupies Quaternary alluvium.

Landform

This floodplain forest occupies relatively broad flats at low topographic positions, along large streams where alluvial deposition dominates. Rivers such as the Sulphur, (and tributaries such as White Oak and Cuthand Creeks), Sabine (and Lake Fork), Trinity (and its major tributaries), Navasota, and portions of the Lower and Middle Brazos (and its major tributaries), Colorado, Guadalupe, Lavaca, Navidad, and San Antonio Rivers may support this system.

Soils

Bottomland Ecological Sites (including Loamy, Sandy, and Clayey) characterize this system.

Parent Description

Dominant communities within this system range from floodplain forests to wet meadows to gravel/sand flats; however, they are linked by underlying soils and the flooding regime. Canopy dominants may include Carya illinoinensis (pecan), Fraxinus americana (white ash), Quercus nigra (water oak), Ulmus crassifolia (cedar elm), Celtis laevigata (sugar hackberry), Ulmus americana (American elm), Quercus fusiformis or Q. virginiana (plateau or coastal live oak), Platanus occidentalis (American sycamore), Acer negundo (boxelder), Gleditsia triacanthos (common honeylocust), Quercus macrocarpa (bur oak), Morus rubra (red mulberry), Fraxinus pennsylvanica (green ash), and Sapindus saponaria var. drummondii (western soapberry). Especially along river margins, species such as Platanus occidentalis (American sycamore), Populus deltoides (eastern cottonwood), and Salix nigra (black willow) may dominate. In this eastern part of the range of the system, Liquidambar styraciflua (sweetgum), Quercus phellos (willow oak), and Betula nigra (river birch) may also be commonly encountered. Seasonally flooded sites, especially within the Trinity River basin, may have Quercus lyrata (overcup oak) as an overstory component. Overgrazing and/or overbrowsing may influence recruitment of overstory species and composition of the understory and herbaceous layers. Shrub species may include Callicarpa americana (American beautyberry), Cephalanthus occidentalis (common buttonbush), Ilex decidua (possumhaw), Ilex vomitoria (yaupon), Sideroxylon lanuginosum (gum bumelia), Diospyros virginiana (common persimmon), Vaccinium arboreum (farkleberry), Juniperus virginiana (eastern redcedar), Cornus drummondii (roughleaf dogwood), and Viburnum rufidulum (rusty blackhaw), which may occur as dense patches following disturbance, but are otherwise generally fairly sparse. In the southern expressions of the system, other shrubs such as Prosopis glandulosa (honey mesquite), Acacia farnesiana (huisache), Diospyros texana (Texas persimmon), and Condalia hookeri (brasil) may be commonly encountered. Vines such as Berchemia scandens (Alabama supplejack), Campsis radicans (common trumpetcreeper), Vitis spp. (grape), Parthenocissus quinquefolia (Virginia creeper), Toxicodendron radicans (poison ivy), Smilax bona-nox (saw greenbrier), and Ampelopsis arborea (peppervine) may be conspicuous. Herbaceous cover includes Elymus virginicus (Virginia wildrye), Verbesina virginica (frostweed), Chasmanthium latifolium (creek oats), Chasmanthium sessiliflorum (narrowleaf woodoats), Carex cherokeensis (Cherokee sedge), Tripsacum dactyloides (eastern gamagrass), Symphyotrichum drummondii var. texanum (Drummond's aster), Calyptocarpus vialis (straggler daisy), Geum canadense (white avens), Sanicula canadensis (Canada snakeroot), Ambrosia trifida (giant ragweed), Panicum virgatum (switchgrass), Galium spp. (bedstraw), Teucrium canadense (American germander), and Carex spp. (sedges). Wetter sites may contain species such as Zizaniopsis miliacea (marshmillet), Rhynchospora spp. (beaksedges), Eleocharis spp. (spikerushes), Nymphaea odorata (American waterlily), and Peltandra virginica (Virginia peltandra). Non-native grasses that may dominate these sites include Cynodon dactylon (bermudagrass), Bothriochloa ischaemum var. songarica (King Ranch bluestem), and Sorghum halepense (Johnsongrass). Herbaceous cover may be quite high, especially in situations where shrub cover is low. The non-native trees Triadica sebifera (Chinese tallow) and Melia azedarach (chinaberry) may be present.

Ecological Mapping Systems

Central Texas: Floodplain Evergreen Forest

Mapping System ID: 1801

As described for the system, but the canopy is dominated by Juniperus virginiana (eastern redcedar). In some cases, this mapped type may have Pinus taeda (loblolly pine) as the canopy dominant.

Distribution Map

Central Texas: Floodplain Evergreen Forest

Photos

Example Central Texas: Floodplain Evergreen Forest.jpg

Central Texas: Floodplain Live Oak Forest

Central Texas: Floodplain Hardwood / Evergreen Forest

Central Texas: Floodplain Hardwood Forest

Mapping System ID: 1804

As described for the system, but deciduous species dominating the canopy.

Distribution Map

Central Texas: Floodplain Hardwood Forest

Photos

Example Central Texas: Floodplain Hardwood Forest.jpg

Public Land Occurrence

Central Texas: Floodplain Evergreen Shrubland

Mapping System ID: 1805

Shrublands of the floodplains of the region that are dominated by Juniperus spp. (juniper) occurring as shrubs, or other evergreen shrubs, such as Ilex vomitoria (yaupon) or the non-native Rosa bracteata (Macartney rose). This type may also represent young Pinus taeda (loblolly pine) stands.

Distribution Map

Central Texas: Floodplain Evergreen Shrubland

Photos

centxfloodplain_juniper_shrubland_site2403.jpg

Central Texas: Floodplain Deciduous Shrubland

Mapping System ID: 1806

Shrublands of the floodplains of the region that are dominated by deciduous shrubs such as Ilex decidua (possumhaw), Prosopis glandulosa (honey mesquite), Salix nigra (black willow), Cornus drummondii (roughleaf dogwood), and/or Cephalanthus occidentalis (common buttonbush). This mapped type may also include areas with sparse woodlands composed of typical deciduous overstory species as described above, or sites in early succession dominated by species such as Prosopis glandulosa (honey mesquite), Acacia farnesiana (huisache), Celtis laevigata (sugar hackberry), or Triadica sebifera (Chinese tallow).

Distribution Map

Central Texas: Floodplain Deciduous Shrubland

Photos

centxfloodplain_deciduous_shrubland_site325.jpg

Public Land Occurrence

Central Texas: Floodplain Herbaceous Vegetation

Mapping System ID: 1807

Floodplains of the region that lack a significant overstory or shrub canopy, but retain cover in the herbaceous layer. Non-native grass species such as Cynodon dactylon (bermudagrass), Bothriochloa ischaemum var. songarica (King Ranch bluestem), and Sorghum halepense (Johnsongrass) may frequently dominate this vegetation type. Tripsacum dactyloides (eastern gamagrass)Panicum virgatum (switchgrass) dominated prairies on lowlands, like those that occur at Knight Prairie and Mill Creek Bottom, may also be mapped as this vegetation type.

Distribution Map

Central Texas: Floodplain Herbaceous Vegetation

Photos

centxfloodplain_herbaceous_site552.jpg

Public Land Occurrence

Central Texas: Floodplain Herbaceous Wetland

Mapping System ID: 1817

Distribution Map

Central Texas: Floodplain Herbaceous Wetland

Central Texas: Floodplain Seasonally Flooded Hardwood Forest

Mapping System ID: 1814

In this eastern portion of the range of the system, the occurrence of bottomlands that are seasonally flooded becomes more common. These sites may be dominated by species that may be more commonly encountered to the east, such as Quercus lyrata (overcup oak) and Quercus phellos (willow oak). Salix nigra (black willow) may also be commonly encountered within the mapped type. Herbaceous cover is very limited due to the frequency of flooding. Shrubs that can withstand frequent inundation, such as Cephalanthus occidentalis (common buttonbush), Planera aquatica (water elm), and Forestiera acuminata (swamp privet), may be present to dominant.

Distribution Map

Central Texas: Floodplain Seasonally Flooded Hardwood Forest

Photos

Example Central Texas: Floodplain Seasonally Flooded Hardwood Forest.jpg

Central Texas: Floodplain Baldcypress Swamp

Mapping System ID: 1824

In the eastern portion of the range of the system, baldcypress swamps are more commonly encountered, particularly in the eastern part of the upper Trinity River basin. These sites are dominated by Taxodium distichum (baldcypress). Some mapped occurrences may be dominated by Planera aquatica (water elm).

Distribution Map

Central Texas: Floodplain Baldcypress Swamp

Photos

Example Central Texas: Floodplain Baldcypress Swamp.jpg

Public Land Occurrence

  • None.