Name:
Pinus palustris / Aristida stricta Woodland Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This woodland vegetation is found in the coastal plains of the southeastern United States from Virginia south to Florida and west to Texas. It is dominated primarily by <i>Pinus palustris</i>, but stands of <i>Pinus clausa</i> in parts of central Florida are also included here. Until the mid-nineteenth century, most of the wooded Southeastern Coastal Plain consisted of this vegetation. The original longleaf ecosystems of the southeastern United States were generally bi-layered communities with the physiognomy maintained by frequent, low-intensity surface fires that removed most small woody plants and thereby kept the canopy open. However, this obscures the remarkable floristic diversity of these systems. This vegetation covers both a large geographic range and a wide latitude of hydrological variation, from very dry to very wet. The components of the understory and ground layer vary greatly across this range of biogeography and hydrology. The driest examples include both sand barrens and scrub dominated by <i>Pinus palustris</i> or <i>Pinus clausa</i>. The sand pine scrub (G008) consists of <i>Pinus clausa</i> over xeromorphic <i>Quercus</i>-dominated shrub vegetation, including <i>Quercus chapmanii, Quercus geminata, Quercus inopina</i>, and <i>Quercus myrtifolia</i>. Xeric longleaf pine-dominated vegetation (G154) consists of open woodlands of <i>Pinus palustris</i> over understories of <i>Quercus incana, Quercus laevis</i>, and/or <i>Quercus margarettae</i>. The ground layer may be sparse, with <i>Schizachyrium scoparium</i> and/or one of the wiregrass forms of <i>Aristida</i> being characteristic. The dry-mesic loamy longleaf (G009) is intermediate in moisture status, with irregularly scattered trees of <i>Pinus palustris</i>, and usually clumps of midstory <i>Quercus</i> spp. and a grassy understory. Mesic longleaf pine flatwoods (G596) are typically found on Spodosol soils, and exhibit an open canopy of <i>Pinus palustris</i> with a grass-dominated ground layer, and a high diversity of forbs. Wet and mesic longleaf pine savannas and flatwoods (G190) are characterized by poorly drained, somewhat poorly drained, and seasonally saturated mineral soils, over a wide range of textures, with at least seasonally high water tables. In natural condition, canopies are open and are commonly monospecific stands of <i>Pinus palustris</i> or may contain other pines such as <i>Pinus elliottii var. elliottii, Pinus serotina</i>, or <i>Pinus taeda</i>. In south Florida, stands are dominated by <i>Pinus elliottii var. densa</i>. In high-quality stands, the ground layer contains a diverse mix of grasses, herbs, and low shrubs. Among the grasses, <i>Aristida beyrichiana</i> or <i>Aristida stricta</i> often dominate within their respective ranges, but <i>Andropogon capillipes</i>, other <i>Andropogon</i> spp., <i>Ctenium aromaticum, Muhlenbergia expansa, Schizachyrium scoparium, Sporobolus floridanus, Sporobolus pinetorum, Sporobolus teretifolius</i>, or other grasses may also dominate.<br /><br />In all of the various kinds of <i>Pinus palustris</i> woodlands, the absence of fire for only a few years to a decade may dramatically alter the physiognomy and composition of the lower strata, with understory hardwoods and shrubs crowding out the grasses and forbs. Exposure to frequent, low-intensity surface fires is the dominant natural ecological process structuring the physiognomy of all of the <i>Pinus palustris</i> savannas and woodlands, influencing the local biodiversity. In some parts of the coastal plain, this vegetation historically constituted one of the most extensive types in the region. Widespread alterations, which followed European settlement, including changes to natural fire regimes, have produced drastic changes to this vegetation, and few large examples are extant that are managed using historical fire regimes. At present, many areas have undergone long periods of time without fire, and this has resulted in greater dominance by shrubs, including <i>Ilex glabra, Serenoa repens</i>, and <i>Vaccinium</i> spp., as well as denser canopies of <i>Pinus elliottii</i> or <i>Pinus taeda</i> rather than <i>Pinus palustris</i>.
Accession Code:
urn:lsid:vegbank.org:commConcept:40438-{691E6ED2-0E8D-4B11-B23D-50F7FE42D537}
Plot-observations of this Community Concept:
0
|
