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M308 Sporobolus vaginiflorus - Schizachyrium scoparium - Clinopodium spp. Southern Barrens & Glade Macrogroup
Type Concept Sentence: The glade and barrens vegetation of this macrogroup is found across the coastal plains of the southeastern United States ranging from the inland parts of Texas and adjacent Oklahoma (including the Edwards Plateau, Lampasas Cutplain, and Crosstimbers) east to northern Florida. Examples may have scattered trees, but are dominated by grasses and forbs, including annuals, succulents, and other plants with adaptations to a very dry environment during the growing season.
Common (Translated Scientific) Name: Poverty Dropseed - Little Bluestem - Calamint species Southern Barrens & Glade Macrogroup
Colloquial Name: Southern Barrens & Glade
Hierarchy Level: Macrogroup
Type Concept: This glade and barrens vegetation is found on various specialized substrates (igneous rock, clay, saline soil, limestone, sandstone) in the coastal plains of the southeastern United States ranging from the inland parts of Texas and adjacent Oklahoma through the coastal plains east to northern Florida. It is currently documented from seven distinct areas with particular substrates, in addition to the central Texas/Oklahoma zone. In inland (non-coastal plain) parts of Texas and adjacent Oklahoma including the Edwards Plateau, Lampasas Cutplain, and Crosstimbers, this vegetation consists of specialized glade communities, frequently dominated by low forbs, annual grasses, and succulents. This vegetation may occur as large to small patches, embedded in a matrix of woodlands, open forests, or perennial grass-dominated prairies. Some characteristic plants in these regions include Lesquerella gordonii, Lesquerella ovalifolia, Schizachyrium scoparium, Sedum nuttallianum, Sedum pulchellum, and Sporobolus vaginiflorus (var. ozarkanus and var. vaginiflorus).
The substrates for the more eastern examples include outcrops of marine sediment and glauconitic clays of the Weches Formation in central eastern Texas; the Catahoula geologic formation of eastern Texas and western Louisiana; distinctive, massive outcrops of igneous substrate ("nepheline syenite") in Saline and Pulaski counties, Arkansas; outcrops of indurated sandstone in the Tifton Upland of the Georgia Coastal Plain (Altamaha Grit); sandstone outcrops of Panhandle Florida; limestone outcrops of Panhandle Florida; and soils with high saline content in portions of the coastal plain west of the Mississippi River.
They will each be described separately. Weches glades are a series of small-patch communities which are endemic to San Augustine, Nacogdoches, and Sabine counties, Texas. Characteristic species include Sedum pulchellum, Clinopodium arkansanum, and Sporobolus vaginiflorus. In addition, the narrowly endemic annuals Lesquerella pallida and Leavenworthia aurea var. texana may be present. Catahoula barrens of eastern Texas and western Louisiana are a vegetational mosaic ranging from herbaceous-dominated areas on shallow soil and exposed sandstone to deeper soils with open woodland vegetation. Glades on distinctive, massive outcrops of igneous substrate ("nepheline syenite") are found in the upper coastal plain of Arkansas, near the Ouachita Mountains. Some typical dominant grasses include Aristida purpurascens, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus clandestinus. Altamaha Grit glade vegetation occurs on sandstone in the Tifton Upland of the Georgia coastal plain. Typical herbaceous species are Allium cuthbertii, Aristida beyrichiana, Bigelowia nuttallii, Coreopsis major, Croton michauxii, Liatris squarrosa, Manfreda virginica, Penstemon dissectus, Schizachyrium tenerum, Phemeranthus teretifolius, and Tephrosia virginiana. A typical dwarf-shrub is Hypericum lloydii. Occurrences can be as large as five acres. This community typically occurs in a matrix of longleaf pine woodlands.
Sandstone glades of Panhandle Florida are dominated by Bigelowia nuttallii. Other characteristic species include Eurybia hemispherica and Schizachyrium scoparium var. scoparium.
On the open small-patch limestone/calcareous glades that are endemic to the Panhandle of Florida and adjacent Georgia, the most characteristic dominant herbaceous species is Schoenus nigricans. Other characteristic taxa are Andropogon sp., Dichanthelium spp., Stenaria nigricans var. nigricans, Helianthus radula, and Muhlenbergia capillaris. Some mesic herbaceous patches dominated by Aquilegia canadensis are also included here.
Saline glades or barrens of the West Gulf Coastal Plain of Louisiana, Texas, and Arkansas are associated with high sodium substrates, with patchy vegetation and much bare soil. Aristida dichotoma is dominant. There are also related examples in the adjacent Ouachita Mountains of Arkansas; these are also accommodated here, even though this technically extends the range off of the coastal plains.
The substrates for the more eastern examples include outcrops of marine sediment and glauconitic clays of the Weches Formation in central eastern Texas; the Catahoula geologic formation of eastern Texas and western Louisiana; distinctive, massive outcrops of igneous substrate ("nepheline syenite") in Saline and Pulaski counties, Arkansas; outcrops of indurated sandstone in the Tifton Upland of the Georgia Coastal Plain (Altamaha Grit); sandstone outcrops of Panhandle Florida; limestone outcrops of Panhandle Florida; and soils with high saline content in portions of the coastal plain west of the Mississippi River.
They will each be described separately. Weches glades are a series of small-patch communities which are endemic to San Augustine, Nacogdoches, and Sabine counties, Texas. Characteristic species include Sedum pulchellum, Clinopodium arkansanum, and Sporobolus vaginiflorus. In addition, the narrowly endemic annuals Lesquerella pallida and Leavenworthia aurea var. texana may be present. Catahoula barrens of eastern Texas and western Louisiana are a vegetational mosaic ranging from herbaceous-dominated areas on shallow soil and exposed sandstone to deeper soils with open woodland vegetation. Glades on distinctive, massive outcrops of igneous substrate ("nepheline syenite") are found in the upper coastal plain of Arkansas, near the Ouachita Mountains. Some typical dominant grasses include Aristida purpurascens, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus clandestinus. Altamaha Grit glade vegetation occurs on sandstone in the Tifton Upland of the Georgia coastal plain. Typical herbaceous species are Allium cuthbertii, Aristida beyrichiana, Bigelowia nuttallii, Coreopsis major, Croton michauxii, Liatris squarrosa, Manfreda virginica, Penstemon dissectus, Schizachyrium tenerum, Phemeranthus teretifolius, and Tephrosia virginiana. A typical dwarf-shrub is Hypericum lloydii. Occurrences can be as large as five acres. This community typically occurs in a matrix of longleaf pine woodlands.
Sandstone glades of Panhandle Florida are dominated by Bigelowia nuttallii. Other characteristic species include Eurybia hemispherica and Schizachyrium scoparium var. scoparium.
On the open small-patch limestone/calcareous glades that are endemic to the Panhandle of Florida and adjacent Georgia, the most characteristic dominant herbaceous species is Schoenus nigricans. Other characteristic taxa are Andropogon sp., Dichanthelium spp., Stenaria nigricans var. nigricans, Helianthus radula, and Muhlenbergia capillaris. Some mesic herbaceous patches dominated by Aquilegia canadensis are also included here.
Saline glades or barrens of the West Gulf Coastal Plain of Louisiana, Texas, and Arkansas are associated with high sodium substrates, with patchy vegetation and much bare soil. Aristida dichotoma is dominant. There are also related examples in the adjacent Ouachita Mountains of Arkansas; these are also accommodated here, even though this technically extends the range off of the coastal plains.
Diagnostic Characteristics: In general, stands of this vegetation are characterized by dominance by low forbs, perennial or annual grasses, and succulents. The most characteristic grasses are Schizachyrium scoparium, Sporobolus vaginiflorus, and various species of Aristida. The other characteristic species vary greatly across the geographic range and substrate diversity of this macrogroup. Some characteristic genera include Anemone, Bigelowia, Bouteloua, Clinopodium, Croton, Delphinium, Lesquerella, Oenothera, Opuntia, Sedum, and Phemeranthus. Many of these genera exhibit morphological adaptations to an environment in which very dry conditions prevail during the growing season.
Examples of this macrogroup are distinguished by their physiognomy (as distinct from surrounding forests and woodlands) and their occurrence on edaphically noteworthy substrates in the coastal plains of the southeastern United States. Glades and barrens are naturally heterogeneous in their physiognomy, displaying herbaceous patches interspersed with small trees and shrubs. Prairies in the same or related areas will occur on deeper soils and (under proper management) display a more uniform grassy appearance. In central Texas, these areas are shallow-soil glades on limestones and related substrates, dominated by low forbs, annual grasses, and succulents. There may be intercalated patches of dry upland and seasonally wet (or saturated) vegetation.
Examples of this macrogroup are distinguished by their physiognomy (as distinct from surrounding forests and woodlands) and their occurrence on edaphically noteworthy substrates in the coastal plains of the southeastern United States. Glades and barrens are naturally heterogeneous in their physiognomy, displaying herbaceous patches interspersed with small trees and shrubs. Prairies in the same or related areas will occur on deeper soils and (under proper management) display a more uniform grassy appearance. In central Texas, these areas are shallow-soil glades on limestones and related substrates, dominated by low forbs, annual grasses, and succulents. There may be intercalated patches of dry upland and seasonally wet (or saturated) vegetation.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The central Texas components of this macrogroup are "carbonate glade and barrens" vegetation. Its members are placed here because they are not comfortably accommodated in either the "northern and central" glades nor in the "southern coastal plain" glades. M308 (formerly Southeastern Coastal Plain Barrens & Glade) has been renamed "Southern Barrens & Glade" to accommodate them; they are placed in the "Comanchian glade and barrens" group. The characteristics of this group may overlap with that of ~Great Plains Cliff, Scree & Rock Vegetation Group (G567)$$, and review is needed to clarify the limits of the two concepts.
This eastern components of this macrogroup represent a number of distinctive associations found in the coastal plains of the southeastern United States which are unified by their presence on the shallow soil of rock outcrops, primarily of circumneutral or alkaline strata or saline soils. Stands are characteristically herbaceous in composition, but may have scattered (to dense) woody plants, depending on management and time since last disturbance (including fire).
This eastern components of this macrogroup represent a number of distinctive associations found in the coastal plains of the southeastern United States which are unified by their presence on the shallow soil of rock outcrops, primarily of circumneutral or alkaline strata or saline soils. Stands are characteristically herbaceous in composition, but may have scattered (to dense) woody plants, depending on management and time since last disturbance (including fire).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: In central Texas, these glades are mosaics of patches of low-statured vegetation, including low forbs, annual grasses, and succulents, which may occur at low cover. Some of the dominant taxa (e.g., annual grasses) may not be evident at all times of the year. At some sites, the vegetated areas may be limited to cracks or depressions in the limestone bedrock where soil has developed and accumulated. There may be intercalated patches of dry upland and seasonally wet (or saturated) vegetation. This vegetation occurs as distinct and mappable patches on limestone; however, it also occurs in smaller patches in a mosaic with savanna and woodland vegetation dominated by perennial grasses, shrubs, and trees.
Further east, stands of this macrogroup are heterogeneous assemblages of herbaceous and woody plants, the proportion and distribution depending on disturbance events and management. The soils are thin, rocky, and in some cases, base-rich (circumneutral to alkaline) or saline. The vegetation of saline soils in Arkansas, Louisiana, and Texas forms a mosaic primarily consisting of open herbaceous or shrubby plant communities.
Further east, stands of this macrogroup are heterogeneous assemblages of herbaceous and woody plants, the proportion and distribution depending on disturbance events and management. The soils are thin, rocky, and in some cases, base-rich (circumneutral to alkaline) or saline. The vegetation of saline soils in Arkansas, Louisiana, and Texas forms a mosaic primarily consisting of open herbaceous or shrubby plant communities.
Floristics: The central Texas (Comanchian) glade vegetation has a strong seasonal aspect and is typically dominated by low forbs, annual grasses, and succulents. Some characteristic plants include Lesquerella gordonii, Lesquerella ovalifolia, Schizachyrium scoparium, Sedum nuttallianum, Sedum pulchellum, and Sporobolus vaginiflorus (var. ozarkanus and var. vaginiflorus). In addition, Nostoc commune (a cyanobacterium) is also common. In central and western Oklahoma, examples are dominated by members of the genus Lesquerella, including Lesquerella gordonii and Lesquerella ovalifolia. Some associates there include Bouteloua curtipendula, Bouteloua hirsuta, Croton monanthogynus, Mentzelia oligosperma, Oenothera macrocarpa (= Oenothera missouriensis), and Opuntia humifusa (Hoagland 2000).
On outcrops of marine sediment and glauconitic clays of the Weches Formation in central eastern Texas, characteristic species include Clinopodium arkansanum, Sedum pulchellum, and Sporobolus vaginiflorus. Other species include Allium drummondii, Anemone caroliniana, Arnoglossum plantagineum (= Cacalia plantaginea), Calylophus berlandieri ssp. berlandieri, Camassia scilloides, Chamaesyce nutans (= Euphorbia nutans), Croton monanthogynus, Dalea compacta var. compacta, Eleocharis occulta, Galium virgatum, Ipomopsis rubra, Isoetes butleri, Liatris punctata var. mucronata (= Liatris mucronata), Minuartia drummondii, Onosmodium bejariense var. bejariense, Opuntia spp., Saxifraga texana, and Thelesperma filifolium. A scattered shrub layer, including Cercis canadensis, Cornus drummondii, Juniperus virginiana, and Sideroxylon lanuginosum, may be present on some sites. Rare or highly restricted species typical of this community are the listed endangered Lesquerella pallida (= Physaria pallida) and Leavenworthia aurea var. texana (= Leavenworthia texana).
Undisturbed examples of the "Catahoula Barrens" of eastern Texas and western Louisiana are dominated by Aristida longespica, Bigelowia nuttallii, Croton michauxii (= Crotonopsis linearis), Dalea compacta var. compacta, Krameria lanceolata, Lechea san-sabeana, Selaginella arenicola, Schizachyrium scoparium, Sporobolus silveanus and Phemeranthus parviflorus (Marietta and Nixon 1984). Woodlands include a Quercus stellata-dominated overstory grading into Pinus palustris-dominated areas. Rare or highly restricted species typical of this community are Gratiola flava and Schoenolirion wrightii.
Glades and barrens on igneous nepheline syenite in Saline and Pulaski counties, Arkansas, may have open stands of Quercus stellata, but trees may be absent. Some typical dominant grasses include Aristida purpurascens, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus clandestinus. Other herbs may include Camassia scilloides, Clinopodium arkansanum, Delphinium carolinianum, Sabatia campestris, and Phemeranthus calycinus. Lichens are common on the rocky substrate of some examples.
Altamaha Grit vegetation occurs on outcrops of indurated sandstone in the Tifton Upland of the Georgia Coastal Plain. Scattered trees and shrubs can be rooted in deeper soils or crevices, including Pinus palustris, Quercus marilandica, and Vaccinium arboreum. Typical herbaceous species are Allium cuthbertii, Aristida beyrichiana, Bigelowia nuttallii, Coreopsis major, Croton michauxii (= Crotonopsis linearis), Liatris squarrosa, Manfreda virginica, Penstemon dissectus, Schizachyrium tenerum, Phemeranthus teretifolius, and Tephrosia virginiana. A typical dwarf-shrub is Hypericum lloydii. Rare or highly restricted species typical of this community are Cuscuta harperi, Evolvulus sericeus, and Penstemon dissectus.
Sandstone glades of Panhandle Florida are dominated by Bigelowia nuttallii. Other characteristic species include Eurybia hemispherica (= Aster paludosus ssp. hemisphericus) and Schizachyrium scoparium var. scoparium. On the open calcareous glades of the Panhandle of Florida (primarily Gadsden and Jackson counties; also adjacent Decatur County, Georgia), the most characteristic dominant herbaceous species is Schoenus nigricans. Other characteristic taxa are Andropogon sp., Dichanthelium spp., Stenaria nigricans var. nigricans (= Hedyotis nigricans var. nigricans), Helianthus radula, and Muhlenbergia capillaris (= var. capillaris). Some additional forbs are Aristida spp., Asclepias viridis, Asclepias viridiflora, Callirhoe papaver, Carex cherokeensis, Delphinium carolinianum ssp. carolinianum, Lepuropetalon spathulatum, Liatris squarrosa, Ponthieva racemosa, Rhynchospora spp., Rudbeckia fulgida, Selaginella ludoviciana, Stachys crenata, Solidago discoidea, and Symphyotrichum pratense (= Aster sericeus var. microphyllus). In addition, Nostoc commune is abundant on the exposed limestone. More shaded limestone outcrops are dominated by Aquilegia canadensis, Arenaria lanuginosa, Asplenium heterochroum, Carex willdenowii, Chaerophyllum tainturieri, Laportea canadensis, Melica mutica, Oxalis sp., Pachysandra procumbens, Pilea pumila, Polymnia laevigata, Thelypteris kunthii, and Urtica chamaedryoides.
Saline glades or barrens of the West Gulf Coastal Plain of Louisiana, Texas, and Arkansas are associated with high sodium substrates, with patchy vegetation and much bare soil. Aristida dichotoma is dominant; other typical species include Anemone caroliniana, Aristida dichotoma, Anagallis minima, Bigelowia nuttallii, Callirhoe papaver, Coreopsis tinctoria, Drosera brevifolia, Geocarpon minimum, Hedeoma hispida, Hordeum pusillum, Houstonia micrantha, Houstonia pusilla, Houstonia rosea, Isolepis carinata (= Isolepis koilolepis), Krigia occidentalis, Lepuropetalon spathulatum, Mimosa strigillosa, Neptunia lutea, Minuartia muscorum (= Minuartia muriculata), Nothoscordum bivalve, Oenothera linifolia, Ophioglossum crotalophoroides, Plantago sp., Polypremum procumbens, Schizachyrium scoparium var. scoparium, Schoenolirion wrightii, Spergularia echinosperma, Sporobolus pyramidatus, Phemeranthus teretifolius, and Tradescantia occidentalis.
On outcrops of marine sediment and glauconitic clays of the Weches Formation in central eastern Texas, characteristic species include Clinopodium arkansanum, Sedum pulchellum, and Sporobolus vaginiflorus. Other species include Allium drummondii, Anemone caroliniana, Arnoglossum plantagineum (= Cacalia plantaginea), Calylophus berlandieri ssp. berlandieri, Camassia scilloides, Chamaesyce nutans (= Euphorbia nutans), Croton monanthogynus, Dalea compacta var. compacta, Eleocharis occulta, Galium virgatum, Ipomopsis rubra, Isoetes butleri, Liatris punctata var. mucronata (= Liatris mucronata), Minuartia drummondii, Onosmodium bejariense var. bejariense, Opuntia spp., Saxifraga texana, and Thelesperma filifolium. A scattered shrub layer, including Cercis canadensis, Cornus drummondii, Juniperus virginiana, and Sideroxylon lanuginosum, may be present on some sites. Rare or highly restricted species typical of this community are the listed endangered Lesquerella pallida (= Physaria pallida) and Leavenworthia aurea var. texana (= Leavenworthia texana).
Undisturbed examples of the "Catahoula Barrens" of eastern Texas and western Louisiana are dominated by Aristida longespica, Bigelowia nuttallii, Croton michauxii (= Crotonopsis linearis), Dalea compacta var. compacta, Krameria lanceolata, Lechea san-sabeana, Selaginella arenicola, Schizachyrium scoparium, Sporobolus silveanus and Phemeranthus parviflorus (Marietta and Nixon 1984). Woodlands include a Quercus stellata-dominated overstory grading into Pinus palustris-dominated areas. Rare or highly restricted species typical of this community are Gratiola flava and Schoenolirion wrightii.
Glades and barrens on igneous nepheline syenite in Saline and Pulaski counties, Arkansas, may have open stands of Quercus stellata, but trees may be absent. Some typical dominant grasses include Aristida purpurascens, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus clandestinus. Other herbs may include Camassia scilloides, Clinopodium arkansanum, Delphinium carolinianum, Sabatia campestris, and Phemeranthus calycinus. Lichens are common on the rocky substrate of some examples.
Altamaha Grit vegetation occurs on outcrops of indurated sandstone in the Tifton Upland of the Georgia Coastal Plain. Scattered trees and shrubs can be rooted in deeper soils or crevices, including Pinus palustris, Quercus marilandica, and Vaccinium arboreum. Typical herbaceous species are Allium cuthbertii, Aristida beyrichiana, Bigelowia nuttallii, Coreopsis major, Croton michauxii (= Crotonopsis linearis), Liatris squarrosa, Manfreda virginica, Penstemon dissectus, Schizachyrium tenerum, Phemeranthus teretifolius, and Tephrosia virginiana. A typical dwarf-shrub is Hypericum lloydii. Rare or highly restricted species typical of this community are Cuscuta harperi, Evolvulus sericeus, and Penstemon dissectus.
Sandstone glades of Panhandle Florida are dominated by Bigelowia nuttallii. Other characteristic species include Eurybia hemispherica (= Aster paludosus ssp. hemisphericus) and Schizachyrium scoparium var. scoparium. On the open calcareous glades of the Panhandle of Florida (primarily Gadsden and Jackson counties; also adjacent Decatur County, Georgia), the most characteristic dominant herbaceous species is Schoenus nigricans. Other characteristic taxa are Andropogon sp., Dichanthelium spp., Stenaria nigricans var. nigricans (= Hedyotis nigricans var. nigricans), Helianthus radula, and Muhlenbergia capillaris (= var. capillaris). Some additional forbs are Aristida spp., Asclepias viridis, Asclepias viridiflora, Callirhoe papaver, Carex cherokeensis, Delphinium carolinianum ssp. carolinianum, Lepuropetalon spathulatum, Liatris squarrosa, Ponthieva racemosa, Rhynchospora spp., Rudbeckia fulgida, Selaginella ludoviciana, Stachys crenata, Solidago discoidea, and Symphyotrichum pratense (= Aster sericeus var. microphyllus). In addition, Nostoc commune is abundant on the exposed limestone. More shaded limestone outcrops are dominated by Aquilegia canadensis, Arenaria lanuginosa, Asplenium heterochroum, Carex willdenowii, Chaerophyllum tainturieri, Laportea canadensis, Melica mutica, Oxalis sp., Pachysandra procumbens, Pilea pumila, Polymnia laevigata, Thelypteris kunthii, and Urtica chamaedryoides.
Saline glades or barrens of the West Gulf Coastal Plain of Louisiana, Texas, and Arkansas are associated with high sodium substrates, with patchy vegetation and much bare soil. Aristida dichotoma is dominant; other typical species include Anemone caroliniana, Aristida dichotoma, Anagallis minima, Bigelowia nuttallii, Callirhoe papaver, Coreopsis tinctoria, Drosera brevifolia, Geocarpon minimum, Hedeoma hispida, Hordeum pusillum, Houstonia micrantha, Houstonia pusilla, Houstonia rosea, Isolepis carinata (= Isolepis koilolepis), Krigia occidentalis, Lepuropetalon spathulatum, Mimosa strigillosa, Neptunia lutea, Minuartia muscorum (= Minuartia muriculata), Nothoscordum bivalve, Oenothera linifolia, Ophioglossum crotalophoroides, Plantago sp., Polypremum procumbens, Schizachyrium scoparium var. scoparium, Schoenolirion wrightii, Spergularia echinosperma, Sporobolus pyramidatus, Phemeranthus teretifolius, and Tradescantia occidentalis.
Dynamics: In the Edwards Plateau of Texas, processes controlling succession in this vegetation are unclear; however, erosion likely plays a major role. Erosion may be exacerbated in some situations by removal of biomass through overgrazing. Erosion mediates the occurrence of this group through its effects on soil depth. within this region, there is an environmental gradient from moister representatives in the east to drier ones in the west. In the Weches Glades of Texas, soils are shallow, rocky, and basic. These factors tend to inhibit growth of woody vegetation. Outcrops are seepy and saturated during winter and early spring but become hard and dry in the summer. In the Catahoula Barrens of Texas, seasonal droughtiness, shallow soils, aluminum toxicity, and periodic fires are important factors that influence the composition and structure of the vegetation.
In the nepheline syenite outcrops of Arkansas, the absence of fire has modified the flora at some examples, with the buildup of leaf litter and organic matter eliminating the glade herbaceous flora even from shallow soils and rocky areas. Historically, fire would have prevented the establishment of fire-intolerant tree species, reduced or eliminated the organic surface layer, fostered an open canopy with fewer (and larger) trees, and maintained the grass-dominated glade communities. This vegetation responds well to fire management and removal of Juniperus. Similar processes and trends operate in the other examples (Catahoula Barrens, Altamaha Grit, Florida Panhandle sandstone and limestone glades).
In the nepheline syenite outcrops of Arkansas, the absence of fire has modified the flora at some examples, with the buildup of leaf litter and organic matter eliminating the glade herbaceous flora even from shallow soils and rocky areas. Historically, fire would have prevented the establishment of fire-intolerant tree species, reduced or eliminated the organic surface layer, fostered an open canopy with fewer (and larger) trees, and maintained the grass-dominated glade communities. This vegetation responds well to fire management and removal of Juniperus. Similar processes and trends operate in the other examples (Catahoula Barrens, Altamaha Grit, Florida Panhandle sandstone and limestone glades).
Environmental Description: The most westerly examples are glades and barrens found at xeric sites on limestones and related substrates, including sandy and gravelly soils. In the Edwards Plateau of Texas, this is primarily hard-bedded limestone such as the Edwards Formation, but also soft-bedded limestone strata such as the Glen Rose and Cow Creek formations. Soil/substrate/hydrology: Stands are found in xeric sites on limestone rock and related substrates, including sandy and gravelly soils. The vegetation of this group consists of glades and barrens on specific and edaphically unusual substrates in the coastal plains of the southeastern United States. The Weches Formation is a marine mudstone with abundant fossils of shallow-water organisms and contains appreciable arsenic, which becomes bioavailable due to weathering. The Eocene Claiborne Group of the Texas Gulf Coastal Plain contains alternating clay and quartzose sand units. The Weches Formation in the Nacogdoches area, a transgressive phase of the Claiborne Group, consists of about 20 m of fossiliferous green clay present as sand-sized aggregates ("greensand"), many of which are fecal pellets. The clay is Fe-rich and has been variously described as "mixed-layer montmorillonite" or as glauconite (Ledger and Judy 2003). Soils are mapped as Trawick series (Mollic Hapludalfs).
The habitat of the Catahoula Barrens includes shallow soil and exposed sandstone, which tend to an herbaceous-dominated vegetation expression, as well as zones of deeper soils with open woodland vegetation. Examples on nepheline syenite are present only in Saline and Pulaski counties, Arkansas, on distinctive, massive outcrops of igneous substrate. Zonal vegetation communities are present around the outcrops. Interior herbaceous-dominated zones can be mesic to wet as springs and small ephemeral streams flow across the rock outcrops and water pools in flat areas. Deeper, more heavily wooded vegetation develops along the flat or slightly sloping outcrop edges.
The Altamaha Grit, now classified by geologists as the Altamaha Formation, outcrops only in southern Georgia; it presumably extends into South Carolina (Huddlestun 1988) but has either been eroded away or remains buried under soil or other types of rock. In addition there are sandstone glades of Panhandle Florida which are dominated by Bigelowia nuttallii.
Small-patch limestone glade and outcrop communities are endemic to the Panhandle of Florida (primarily Gadsden and Jackson counties) and adjacent Decatur County, Georgia. This vegetation includes a range of open limestone outcrops on hillsides and hill crests where soils are either very shallow or absent. This grades into shaded, mesic lower slopes near the floodplain of the Chipola River. The soils and geology of these panhandle Florida limestone examples has been well documented. In Gadsden County, they occur on limestone outcrops of the Miocene Chattahoochee Formation (Rupert 1990) primarily between the 90- and 120-foot contour lines (27-37 m MSL). In Jackson County, they are found primarily on rather soft, chalky Oligocene Marianna Limestone (Moore 1955, H. Means pers. comm. 2007) between the 130- and 150-foot contours (40-46 m MSL). These glades usually occupy areas too small to be distinguished at the scale of county soil survey maps. They may occasionally be shown as rock outcrops within the matrix of the surrounding forest soils. In Gadsden County, these matrix soils are Binnsville soils or Cuthbert, Boswell, and Susquehanna soils on moderate to steep slopes (Thomas et al. 1961b). In Jackson County, the matrix soils are the Oktibbeha variant rock outcrop complex (Duffee et al. 1979).
The saline examples in Arkansas, Louisiana, and Texas occur on soils with high saline content, which in the most extreme examples are generally not conducive to woody plant growth. The vegetation is patchy, with much bare soil.
The habitat of the Catahoula Barrens includes shallow soil and exposed sandstone, which tend to an herbaceous-dominated vegetation expression, as well as zones of deeper soils with open woodland vegetation. Examples on nepheline syenite are present only in Saline and Pulaski counties, Arkansas, on distinctive, massive outcrops of igneous substrate. Zonal vegetation communities are present around the outcrops. Interior herbaceous-dominated zones can be mesic to wet as springs and small ephemeral streams flow across the rock outcrops and water pools in flat areas. Deeper, more heavily wooded vegetation develops along the flat or slightly sloping outcrop edges.
The Altamaha Grit, now classified by geologists as the Altamaha Formation, outcrops only in southern Georgia; it presumably extends into South Carolina (Huddlestun 1988) but has either been eroded away or remains buried under soil or other types of rock. In addition there are sandstone glades of Panhandle Florida which are dominated by Bigelowia nuttallii.
Small-patch limestone glade and outcrop communities are endemic to the Panhandle of Florida (primarily Gadsden and Jackson counties) and adjacent Decatur County, Georgia. This vegetation includes a range of open limestone outcrops on hillsides and hill crests where soils are either very shallow or absent. This grades into shaded, mesic lower slopes near the floodplain of the Chipola River. The soils and geology of these panhandle Florida limestone examples has been well documented. In Gadsden County, they occur on limestone outcrops of the Miocene Chattahoochee Formation (Rupert 1990) primarily between the 90- and 120-foot contour lines (27-37 m MSL). In Jackson County, they are found primarily on rather soft, chalky Oligocene Marianna Limestone (Moore 1955, H. Means pers. comm. 2007) between the 130- and 150-foot contours (40-46 m MSL). These glades usually occupy areas too small to be distinguished at the scale of county soil survey maps. They may occasionally be shown as rock outcrops within the matrix of the surrounding forest soils. In Gadsden County, these matrix soils are Binnsville soils or Cuthbert, Boswell, and Susquehanna soils on moderate to steep slopes (Thomas et al. 1961b). In Jackson County, the matrix soils are the Oktibbeha variant rock outcrop complex (Duffee et al. 1979).
The saline examples in Arkansas, Louisiana, and Texas occur on soils with high saline content, which in the most extreme examples are generally not conducive to woody plant growth. The vegetation is patchy, with much bare soil.
Geographic Range: The glade and barrens vegetation of this macrogroup is found across coastal plains of the southeastern United States ranging from the inland parts of Texas and adjacent Oklahoma (including the Edwards Plateau, Lampasas Cutplain, and Crosstimbers) east to northern Florida. Specific areas in the eastern part of this range include in a localized region of eastern Texas, primarily in San Augustine, Nacogdoches, and Sabine counties; portions of western Louisiana and eastern Texas; the Upper West Gulf Coastal Plain of Saline and Pulaski counties, Arkansas (on nepheline syenite); and the Panhandle of Florida (primarily Gadsden and Jackson counties and adjacent Decatur County, Georgia). In addition, included here are saline glades and barrens of the coastal plain of Arkansas, Louisiana, and Texas.
Nations: US
States/Provinces: AR, FL, GA, LA, OK, TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860649
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.2 Temperate Grassland & Shrubland Formation | F012 | 2.B.2 |
| Division | 2.B.2.Nh Southeastern North American Grassland & Shrubland Division | D102 | 2.B.2.Nh |
| Macrogroup | 2.B.2.Nh.3 Poverty Dropseed - Little Bluestem - Calamint species Southern Barrens & Glade Macrogroup | M308 | 2.B.2.Nh.3 |
| Group | 2.B.2.Nh.3.a Little Bluestem - Limestone Calamint - Nuttall''s Rayless-goldenrod Southeastern Coastal Plain Barrens & Glade Group | G584 | 2.B.2.Nh.3.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Catahoula Barrens (Bridges and Orzell 1989a)
= Upland Glade (FNAI 1990)
? Upland Glade, Chalky Limestone Glade subtype (FNAI 1992b)
= Upland Glade (FNAI 1990)
? Upland Glade, Chalky Limestone Glade subtype (FNAI 1992b)
- Arkansas Geological Commission. 2006. Nepheline syenite. [http://www.state.ar.us/agc/novaculi.htm]. (accessed January 14, 2006)
- Bridges, E. L., and S. L. Orzell. 1989a. Longleaf pine communities of the West Gulf Coastal Plain. Natural Areas Journal 9:246-263.
- Carr, William R. (Bill). Personal communication. Research Scientist, Botany, The Nature Conservancy of Texas, Texas Natural History Survey, San Antonio, TX.
- Coultas, C. L. 1983. Examination of soils associated with four small "limestone glade communities" surrounded by forest in the hills of western Gadsden County. Florida Natural Areas Inventory, Tallahassee.
- Duffee, E. M., W. J. Allen, and H. C. Ammons. 1979. Soil survey of Jackson County, Florida. USDA Soil Conservation Service in cooperation with the University of Florida Institute of Food and Agricultural Sciences, Agricultural Experiment Stations, Soil Science Department, Gainesville, FL.
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- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Hoagland, B. 2000. The vegetation of Oklahoma: A classification for landscape mapping and conservation planning. The Southwestern Naturalist 45(4):385-420.
- Huddlestun, P. F. 1988. A revision of the lithostratigraphic units of the Coastal Plain of Georgia. The Miocene through Holocene. Bulletin 104. Georgia Geologic Survey, Environmental Protection Division, Georgia Department of Natural Resources, Atlanta. 162 pp. plus attachments.
- Ledger, E. B., and K. Judy. 2003. Elevated arsenic levels in the Weches Formation Nacogdoches County, Texas. [http://www.geology.sfasu.edu/weches.pdf].
- Leonard, S. W., and W. W. Baker. 1982. Biological survey of the Apalachicola Ravines Biotic Region of Florida. Report to the Florida state office of The Nature Conservancy and to the Florida Natural Areas Inventory, Tallahassee.
- Marietta, K. L., and E. S. Nixon. 1984. Vegetation of an open, prairie-like community in eastern Texas. Texas Journal of Science 36:25-32.
- Means, H. Personal communication. Geologist with the Florida Geological Survey, Tallahassee.
- Moore, W. E. 1955. Geology of Jackson County, Florida. Florida Geological Survey Bulletin No. 37. 101 pp.
- Rupert, F. R. 1990. Geology of Gadsden County, Florida. Florida Geological Survey, Bulletin No. 62. 61 pp.
- Thomas, B. P., H. H. Weeks, and M. W. Hazen, Jr. 1961b. Soil survey of Gadsden County, Florida. USDA Soil Conservation Service in cooperation with the University of Florida Institute of Food and Agricultural Sciences, Agricultural Experiment Stations, Soil Science Department, Gainesville, FL.
- Ward, D. B., and A. K. Gholson. 1987. The hidden abundance of Lepuropetalon spathulatum (Saxifragaceae) and its first reported occurrence in Florida. Castanea 52:59-67.