Columbia Bottomlands Forest and Woodland

Geology

On extensive Quaternary alluvium along rivers and major drainages, but also found on adjacent Beaumont and Lissie Formations.

Landform

On the level to gently rolling uplands of the coastal prairie and floodplains. Significant local topographic relief associated with terraces, depressions, levees and swales of the floodplains of the lower Colorado, Brazos, and San Bernard Rivers and their major tributaries.

Soils

Primarily on the Clayey or Loamy Bottomland ecological site types, but also found on blackland and claypan soils within the basin.

Parent Description

This system occurs on Quaternary alluvium and adjacent Pleistocene terraces (Beaumont and Lissie Formations) along the Brazos, San Bernard, and Colorado Rivers (as they pass through these Pleistocene formations), and adjacent streams such as Oyster Creek, Caney Creek, and Linnville Bayou. Chocolate Bayou represents the eastern extent of this system as the forest grades into systems more closely resembling the West Gulf Coastal Plain Small Stream and River Forest system to the northeast. Tres Palacios Creek represents the southwestern limit of this system, as floodplains further south and west share closer affinity to coastal rivers such as the Mission and Aransas. This system occupies a generally level landscape, punctuated by a series of swales, depressions, and natural levees. Much of the flooding experienced by this system results from seasonal precipitation and tropical storms, not from over-bank flooding. Over-bank flooding is infrequent, occurring about every 15 to 25 years (M. Lange, Pers. Comm.). Soils are frequently clayey bottomlands (such as Pledger or Brazoria clays) or loamy bottomlands (such as those of the Asa or Norwood series). This system expresses a range of communities along a moisture gradient ranging from the wettest sites along stream margins and depressions, to somewhat drier sites on ridges and natural levees. Herbaceous communities and open water typically characterize the wettest sites, with species such as Eleocharis quadrangulata (squarestem spikesedge), Sagittaria graminea (grassy arrowhead), Sagittaria platyphylla (delta arrowhead), Ludwigia spp. (water-primroses), Saururus cernuus (lizard's tail), Azolla caroliniana (Carolina mosquito-fern), and Lemna obscura (little duckweed). Such very wet sites may have Taxodium distichum (baldcypress) and Salix nigra (black willow) in the overstory, or may be shrub swamps dominated by Cephalanthus occidentalis (common buttonbush) and/or Forestiera acuminata (swamp privet). Sites inundated somewhat less frequently, such as meander scars, abandoned oxbows, and channels, are often dominated in the overstory by species including Fraxinus pennsylvanica (green ash), Ulmus americana (American elm), and Carya aquatica (water hickory), while the woody understory of these sites are typically open and may be dominated by Cephalanthus occidentalis (common buttonbush) and/or Forestiera acuminata (swamp privet). Rarely, Leitneria floridana (corkwood) may be a conspicuous component of the shrub layer. Herbaceous cover is often patchy and can include species such as Phanopyrum gymnocarpon (savannah panicum), Echinodorus cordifolius (heartleaf burhead), Carex spp. (carices), Rhynchospora corniculata (horned beakrush), Saururus cernuus (lizard's tail), Polygonum punctatum (water smartweed), Hygrophila lacustris (Gulf swampweed), Boehmeria cylindrica (false nettle), Mikania scandens (climbing hemp-weed), and Lemna obscura (little duckweed). Flats and ridges that are only occasionally flooded are often dominated by Celtis laevigata (sugar hackberry), Ulmus crassifolia (cedar elm), Quercus nigra (water oak), and Quercus shumardii (Shumard oak). Shrubs on these sites include Ilex vomitoria (yaupon), Sapindus saponaria var. drummondii (western soapberry), Malvaviscus arboreus var. drummondii (Drummond Turk's cap), Symphoricarpos orbiculatus (coralberry), and Callicarpa americana (American beautyberry). Sabal minor (dwarf palmetto) and Carex cherokeensis (Cherokee sedge) are more abundant on these sites, and other species such as Toxicodendron radicans (poison ivy), Chasmanthium sessiliflorum (narrowleaf woodoats), Chasmanthium latifolium (creek oats), Calyptocarpus vialis (straggler daisy), Oplismenus hirtellus ssp. setarius (basketgrass), and Polygonum virginianum (jump seed) may be present. Clay backflats in this landscape may be dominated by Quercus virginiana (coastal live oak) and Carya illinoinensis (pecan), and Quercus virginiana (coastal live oak) may also share dominance with other canopy species on natural levees of these river systems. Blackland soils on the Pleistocene surface (such as those of the Lake Charles series) are often occupied by a forest dominated or co-dominated by Quercus nigra (water oak), Celtis laevigata (sugar hackberry), Ulmus crassifolia (cedar elm), Fraxinus pennsylvanica (green ash), and less frequently Quercus virginiana (coastal live oak). The shrub layer on these sites is often well-developed and typically dominated by Ilex vomitoria (yaupon), sometimes with Sabal minor (dwarf palmetto), Cornus drummondii (roughleaf dogwood), and Prunus caroliniana (Carolina laurelcherry) also present. Vines are commonly encountered including species such as Vitis mustangensis (mustang grape), Toxicodendron radicans (poison ivy), Ampelopsis arborea (peppervine), and Berchemia scandens (Alabama supplejack). Chasmanthium sessiliflorum (narrowleaf woodoats), Carex cherokeensis (Cherokee sedge), Carex crus-corvi (crowfoot sedge), Urochloa platyphylla (broadleaf signalgrass), and Juncus spp. (rushes) and numerous other species are commonly found in the herbaceous layer. It is unclear whether these typically prairie dominated surfaces are now occupied by woodland and forest due to a disruption in natural fire cycle and disturbance, or whether the unique hydrology or other environmental factors of the Columbia Bottomlands leads to this incongruity. Tillandsia usneoides (Spanish moss) is a frequently encountered epiphyte in these forests. Riverside woodlands, along major rivers, have Platanus occidentalis (American sycamore) and Populus deltoides (eastern cottonwood) in the canopy (David Rosen, Pers. Comm.). The non-native tree Triadica sebifera (Chinese tallow) may often be encountered, sometimes as a significant or dominant component of the canopy.