Print Report
G034 Quercus michauxii - Quercus laurifolia - Liquidambar styraciflua Floodplain Forest Group
Type Concept Sentence: This vegetation is dominated by members of the genus Quercus, including Quercus laurifolia, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus pagoda, Quercus phellos, Quercus shumardii, and Quercus texana, along with Carpinus caroliniana, Liquidambar styraciflua, Nyssa biflora, Ulmus spp., and other trees tolerant of flooding and wet conditions, being generally known as bottomland hardwood forests. It is found primarily in the Atlantic and Gulf coastal plains, as well as the Mississippi River Alluvial Plain and adjacent Upper East Gulf Coastal Plain, and the adjacent southern Piedmont.
Common (Translated Scientific) Name: Swamp Chestnut Oak - Laurel Oak - Sweetgum Floodplain Forest Group
Colloquial Name: Oak - Sweetgum Floodplain Forest
Hierarchy Level: Group
Type Concept: This wetland forest group is a very broad one, in its environmental amplitude, its floristic diversity, and its biogeographic range. It is primarily affiliated with the Atlantic and Gulf coastal plains from Virginia to Texas, and the Mississippi River Alluvial Plain and adjacent Upper East Gulf Coastal Plain from Illinois, Missouri and Kentucky south to Mississippi and Louisiana, but it also includes wetland, swamp, and riparian forests of the southern Piedmont from Virginia to Alabama. This group primarily encompasses vegetation dominated by members of the genus Quercus, along with Liquidambar styraciflua, Ulmus spp., and other trees, being generally known as bottomland hardwood forests. It primarily encompasses communities of streams and rivers of all orders and sizes, as well as some forests of isolated wetlands, including depression ponds. This group includes forests known as "blackwater" as well as "brownwater" examples. Some characteristic components of blackwater forests include Nyssa biflora, as well as Quercus laurifolia, Quercus lyrata, Quercus nigra, Pinus taeda, and Magnolia virginiana in higher portions of the floodplain. Nyssa aquatica is generally scarce or absent. Brownwater examples are also likely to contain Platanus occidentalis, Celtis laevigata, Fraxinus pennsylvanica, Acer negundo, and others. These stands also may include Quercus laurifolia, Quercus michauxii, Quercus pagoda, and sometimes Liquidambar styraciflua. There is also some floristic variation between shorter and longer hydroperiod examples. Quercus michauxii, Quercus pagoda, and Quercus shumardii are characteristic of shorter hydroperiod examples, and Quercus laurifolia, Quercus lyrata, Quercus phellos, and Nyssa biflora of longer hydroperiod ones.
Except in the very wet examples, understory, shrub and herb layers are generally well-developed and woody vines are also prominent. Arundinaria gigantea is a common understory component in these forests on natural levees and higher point bars, and may become dominant after thinning or removal of the overstory. Sandbars dominated by Salix spp. and/or Populus spp. may have an open-canopy (woodland) structure.
Most vegetation placed here is associated with rivers and streams, but some are referred to as "flatwoods." It includes riverfront vegetation, which is generally temporarily (but rarely seasonally) flooded, on point bars and natural levees adjacent to the river that formed them, as well as high bottomlands, some low bottomlands, as well as levees, ridges, terraces, and some sloughs and abandoned channel segments. These features are large and well-defined in larger river systems, but the forests of smaller floodplains and bottomlands are not differentiated by these depositional landforms, because these features are small and flooding regimes are variable. The hydrologic regime and the hydroperiod are also highly diverse in this group of forests.
Except in the very wet examples, understory, shrub and herb layers are generally well-developed and woody vines are also prominent. Arundinaria gigantea is a common understory component in these forests on natural levees and higher point bars, and may become dominant after thinning or removal of the overstory. Sandbars dominated by Salix spp. and/or Populus spp. may have an open-canopy (woodland) structure.
Most vegetation placed here is associated with rivers and streams, but some are referred to as "flatwoods." It includes riverfront vegetation, which is generally temporarily (but rarely seasonally) flooded, on point bars and natural levees adjacent to the river that formed them, as well as high bottomlands, some low bottomlands, as well as levees, ridges, terraces, and some sloughs and abandoned channel segments. These features are large and well-defined in larger river systems, but the forests of smaller floodplains and bottomlands are not differentiated by these depositional landforms, because these features are small and flooding regimes are variable. The hydrologic regime and the hydroperiod are also highly diverse in this group of forests.
Diagnostic Characteristics: Examples are most typically closed-canopy forests found in bottomlands or floodplains. Characteristic trees include Liquidambar styraciflua, Nyssa biflora, Quercus laurifolia, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus pagoda, Quercus phellos, Quercus shumardii, and Quercus texana, along with Carpinus caroliniana, Liquidambar styraciflua, Ulmus spp., and other trees tolerant of flooding and wet conditions. Typical shrubs include Ilex decidua and Arundinaria gigantea.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This group does not include associations and alliances dominated by Taxodium distichum, Taxodium ascendens, and Nyssa aquatica. These are generally known as "bald-cypress - tupelo forests" and are accommodated in a different group. Forests dominated by Fagus grandifolia with or without Magnolia grandiflora belong in mesic groups, whether they are clearly in uplands or in upland-floodplain transition areas. There may be floristic overlap in terms of the composition of individual stands of this group (G034) and those of ~Southern Ash - Elm - Willow Floodplain Forest Group (G759)$$, but stands of G034 will typically be dominated by Liquidambar - Quercus and tend to occur in less frequently disturbed habitats. Both are in ~Southern Coastal Plain Floodplain Forest Macrogroup (M031)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Examples are most typically closed-canopy flooded and bottomland forests, dominated by tall trees.
Floristics: Characteristic canopy tree species are Liquidambar styraciflua and a variety of Quercus spp., including Quercus laurifolia, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus pagoda, Quercus phellos, Quercus shumardii, Quercus texana, and others, which vary in their hydrological tolerance. The forest canopy will also usually contain a mix of mesophytic and widespread species such as Acer rubrum, Liquidambar styraciflua, and Liriodendron tulipifera, along with characteristic alluvial and bottomland species such as Acer negundo, Acer saccharinum, Betula nigra, Carya illinoinensis, Celtis laevigata, Fraxinus pennsylvanica, Gleditsia triacanthos, Platanus occidentalis, Populus deltoides, Salix nigra, and Ulmus americana. Quercus virginiana may be present within its range. Ulmus crassifolia may be more commonly found west of the Mississippi River. Some small trees and shrubs include Carpinus caroliniana, Cornus florida, Ilex decidua, Ilex opaca var. opaca, and Viburnum dentatum. Southern stands may contain Sabal minor. The perennial graminoid bamboo Arundinaria gigantea (= ssp. gigantea) may dominate the shrub stratum of some forests, such as on natural levees and higher point bars, or it may form non-forested stands called "canebrakes." Vines are common, including Nekemias arborea (= Ampelopsis arborea), Berchemia scandens, Campsis radicans, Smilax bona-nox, Toxicodendron radicans, and Vitis rotundifolia. Fagus grandifolia may be present in drier portions, mixed with the other species, but stands in which it is dominant are probably accommodated in mesic upland groups. Successional areas are often strongly dominated by Pinus taeda with Liquidambar styraciflua and/or Liriodendron tulipifera, but with a natural understory composition. Lower strata in the forests may be either primarily of mesophytic species shared with moist uplands systems, or a mix of mesophytic and bottomland species. Nyssa aquatica is generally scarce or absent. Higher portions of the floodplain have forests with combinations of a small set of wetland oaks and other species, including Liquidambar styraciflua, Magnolia virginiana, Pinus taeda, Quercus laurifolia, Quercus lyrata, Quercus nigra, and other species. Herbs in wetter examples may include Boehmeria cylindrica, Commelina virginica, Leersia lenticularis, and Onoclea sensibilis. Some other examples have very diverse herbaceous layers, including Bidens aristosa, Carex cherokeensis, Carex debilis, Carex digitalis, Carex joorii, Chasmanthium latifolium, Geum canadense, Glyceria striata, Leersia virginica, and Polygonum hydropiperoides.
Dynamics: Flooding is an important ecological factor in examples of this group and may be the most important factor separating this vegetation from that of adjacent uplands. In addition to disturbance, floods bring moisture and nutrient input, deposit sediment, exclude non-flood-tolerant species and disperse plant seeds. It is unclear how important aquatic fauna are when the system is flooded, but they may be important. The small flows, low gradient, and binding of sediment by vegetation limit channel shifts and sediment movement, but floods may cause local disturbance by scouring. Small rivers and streams, with small watersheds, have shorter and more variable flooding regimes than larger rivers. Floods tend to be of short duration and unpredictably variable as to season and depth. Flood waters may have significant energy in higher-gradient systems, but scouring and reworking of sediment rarely affect more than small patches. They are important in maintaining the small non-forested patches.
Most of these forests exist naturally as multi-aged old-growth forests driven by gap-phase regeneration. Windthrow is probably the most important cause of gaps, as wind disturbance is perhaps more important than in uplands because of frequently wet soils, less dense soils, and more shallow-rooted trees.
Fire does not appear to be a dominant factor, and most floodplain vegetation is not very flammable. Fire is probably more important in small stream examples than in larger river ones, because distances to uplands are short and because stream channels and sloughs are smaller and less effective as firebreaks. However, most of the vegetation is not very flammable and usually will not carry fire. However, historical references to canebrakes dominated by Arundinaria gigantea suggest that fire may have once been more possible and more important in at least some portions of stands.
Stands of this group with a shorter hydroperiod are subject to greater disturbance effects than those with longer hydroperiods. A variety of direct and indirect modern human influences have affected all stands. Many larger rivers have been dammed, and power generation and regulation of waterflow create unnatural flood regimes. Extensive erosion of uplands, caused by many years of poor agricultural practices, transported large amounts of sediment into floodplains. River bottoms were the focus of agriculture among Native Americans, so some members of this group have a long history of human clearing. A number of exotic plant species have invaded floodplains as well.
Most of these forests exist naturally as multi-aged old-growth forests driven by gap-phase regeneration. Windthrow is probably the most important cause of gaps, as wind disturbance is perhaps more important than in uplands because of frequently wet soils, less dense soils, and more shallow-rooted trees.
Fire does not appear to be a dominant factor, and most floodplain vegetation is not very flammable. Fire is probably more important in small stream examples than in larger river ones, because distances to uplands are short and because stream channels and sloughs are smaller and less effective as firebreaks. However, most of the vegetation is not very flammable and usually will not carry fire. However, historical references to canebrakes dominated by Arundinaria gigantea suggest that fire may have once been more possible and more important in at least some portions of stands.
Stands of this group with a shorter hydroperiod are subject to greater disturbance effects than those with longer hydroperiods. A variety of direct and indirect modern human influences have affected all stands. Many larger rivers have been dammed, and power generation and regulation of waterflow create unnatural flood regimes. Extensive erosion of uplands, caused by many years of poor agricultural practices, transported large amounts of sediment into floodplains. River bottoms were the focus of agriculture among Native Americans, so some members of this group have a long history of human clearing. A number of exotic plant species have invaded floodplains as well.
Environmental Description: This group occurs near streams and small rivers, on floodplains and terraces affected by river flooding and on emergent bars and banks within channels. Depositional landforms, including levees, sloughs, ridges, terraces, and abandoned channel segments may be present within stands. The substrate is primarily alluvium. Soils are usually sandy to loamy, but include local clayey and gravelly areas. Soils are generally fertile. The presence of alluvial soils may be as important a factor as ongoing flooding in differentiating these systems from adjacent uplands. Emergent and vegetated bars composed of material ranging from gravel to cobbles occur occasionally but are generally not extensive or as distinctive as they are on larger rivers. Floods are generally of short duration, and wetness is a major influence only within channels and where water is ponded in local depressions. The geologic substrate may be of any kind, but areas on Triassic sediments tend to have large floodplain systems even on fairly small streams.
Blackwater examples occur in floodplains of small streams of the coastal plain that carry little mineral sediment. These streams have their headwaters in sandy portions of the coastal plain. The water is usually strongly stained by tannins but has little suspended clay and is not turbid. Depositional landforms may be absent or may be present in limited variety and of small size. Soils are generally sandy in drier portions of the floodplain, mucky in wetter portions, or may be uniform organic soils. Soils are usually strongly acidic, but spring-fed rivers may have calcareous water and non-acidic soils. Flooding ranges from semipermanent in the wettest floodplains to intermittent and short in higher-gradient streams. Some small blackwater streams have most of their flow from sandhill seepage and have limited fluctuation in water levels.
In contrast, brownwater or redwater river examples occur in floodplains of medium to small coastal plain rivers that carry significant mineral sediment. These rivers have their headwaters in the Piedmont, Blue Ridge, Interior Plateaus, or in portions of the coastal plain where fine-textured sediment predominates. The water generally carries substantial amounts of silt, clay, and sometimes sand. Depositional landforms such as point bars, natural levees, backswamps, and ridge-and-swale systems (scrollwork) are well-developed and form patterns of significant variation in flooding duration and nutrient input. Soil texture varies from sandy to clayey. Soils are generally fertile and not strongly acidic. Flooding ranges from semipermanent in the wettest areas to intermittent and short on the higher portions of the floodplain. The highest terraces may no longer flood at all and will be occupied by upland vegetation.
Blackwater examples occur in floodplains of small streams of the coastal plain that carry little mineral sediment. These streams have their headwaters in sandy portions of the coastal plain. The water is usually strongly stained by tannins but has little suspended clay and is not turbid. Depositional landforms may be absent or may be present in limited variety and of small size. Soils are generally sandy in drier portions of the floodplain, mucky in wetter portions, or may be uniform organic soils. Soils are usually strongly acidic, but spring-fed rivers may have calcareous water and non-acidic soils. Flooding ranges from semipermanent in the wettest floodplains to intermittent and short in higher-gradient streams. Some small blackwater streams have most of their flow from sandhill seepage and have limited fluctuation in water levels.
In contrast, brownwater or redwater river examples occur in floodplains of medium to small coastal plain rivers that carry significant mineral sediment. These rivers have their headwaters in the Piedmont, Blue Ridge, Interior Plateaus, or in portions of the coastal plain where fine-textured sediment predominates. The water generally carries substantial amounts of silt, clay, and sometimes sand. Depositional landforms such as point bars, natural levees, backswamps, and ridge-and-swale systems (scrollwork) are well-developed and form patterns of significant variation in flooding duration and nutrient input. Soil texture varies from sandy to clayey. Soils are generally fertile and not strongly acidic. Flooding ranges from semipermanent in the wettest areas to intermittent and short on the higher portions of the floodplain. The highest terraces may no longer flood at all and will be occupied by upland vegetation.
Geographic Range: This group is found throughout the Atlantic Coastal Plain, from southeastern Virginia to southeastern Georgia, in the Gulf Coastal Plain from Georgia to Texas, in the Mississippi Alluvial Plain and adjacent Upper East Gulf Coastal Plain from Missouri, extreme southern Illinois and western Kentucky south to Mississippi and Louisiana, and in the Piedmont from Alabama to southern Virginia. The northern boundary in Virginia is roughly the watershed of the James River.
Nations: US
States/Provinces: AL, AR, FL, GA, IL, KY, LA, MD, MO, MS, NC, OK, SC, TN, TX, VA, WV
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.833241
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Bottomland Forest (FNAI 1990)
> Floodplain Forest (FNAI 1990)
> Floodplain Hardwood Pine Forest (Marks and Harcombe 1981)
> Floodplain Swamp (FNAI 1990)
< Southern Floodplain Forests (Sharitz and Mitsch 1993)
> Floodplain Forest (FNAI 1990)
> Floodplain Hardwood Pine Forest (Marks and Harcombe 1981)
> Floodplain Swamp (FNAI 1990)
< Southern Floodplain Forests (Sharitz and Mitsch 1993)
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