Home/Ecosystems/ Texas Saline Coastal Prairie

Texas Saline Coastal Prairie

EVT 7486

CES203.543GNRHerbRiparian

Summary

This system encompasses grassland vegetation occurring along the Gulf Coast of Texas on saline and nonsaline soils on level topography of the Beaumont Formation and in brackish marshes. These areas are often saturated by local rainfall and periodically flooded by saline waters during major storm events. Outliers also occur as scattered patches in salt flats. It is characteristically dominated by Spartina spartinae, a tall (1.5 m) warm-season perennial bunchgrass; other dominants may include Schizachyrium littorale and Muhlenbergia capillaris. This system also includes depressions often dominated by Spartina patens. Saline prairie continues to occupy extensive areas, though quality of the system is often degraded by the invasion of woody shrubs due to the absence of regular fire. Fire is an important ecological process needed to maintain this system, though periodic submersion with saltwater during storm events also helps to control the invasion of woody species.

Source: NatureServe Explorer

Vegetation

This system is characteristically dominated by Spartina spartinae, which may occur in nearly monotypic stands; other dominants may include Schizachyrium littorale and Muhlenbergia capillaris. This system includes depressions often dominated by Spartina patens. Other graminoids that may be present to abundant include Schizachyrium scoparium, Andropogon glomeratus, Panicum virgatum, or Sporobolus indicus. On lower, somewhat wetter sites, Aristida oligantha, Paspalum hartwegianum, Sporobolus virginicus, Paspalum vaginatum, and Distichlis spicata may be common. Forbs are generally uncommon but may include species such as Borrichia frutescens, Solidago sempervirens, Iva angustifolia, Euthamia spp., or other species more common to the non-saline soils nearby or the salt marsh that may also be nearby. Microtopographic highs in the form of pimple mounds often have species more characteristic of less saline adjacent habitats. Shrubby species may invade the prairie, commonly including species such as Iva frutescens, Prosopis glandulosa, Vachellia farnesiana (= Acacia farnesiana), Lycium carolinianum, Tamarix sp., and Baccharis halimifolia (Elliott 2011).

Source: NatureServe Explorer

Environment

This system occurs on saline and nonsaline soils of the Pleistocene Beaumont Formation that are often saturated by local rainfall and periodically flooded by saline waters during major storm events. Landforms are mostly level or very gently undulating, and typically found near the coast. These sites may be inundated by saltwater during storm surges. Pimple mounds may lend some local topographic variation to the otherwise level surface. Soils are very deep, somewhat poorly to poorly drained, often with high salinity and/or sodicity, at least at some depth. These may be loams or clays. These soils may be saturated from local rainfall or occasionally from storm surges (Elliott 2011). This system often forms a band between coastal salt marshes and coastal nonsaline prairie.

Source: NatureServe Explorer

Dynamics

Fire is an important ecological process needed to maintain this system. Periodic submersion with saltwater during storm events also helps to control the invasion of woody species and contributes to higher soil salinity levels.

Source: NatureServe Explorer

Threats

Primary historic and current threats to this system include conversion to agriculture and coastal development, and alterations to the natural fire regime. In the absence of regular fire, this system will be invaded by woody shrubs. If changes in regional climate bring about an increase in precipitation, this could lead to an increase in woody encroachment; a decrease in precipitation could lead to loss of the wet prairie components of this system. Due to its proximity to the coast and coastal marshes, sea-level rise could further impact this system by saltwater inundation. Sea-level rise is expected to have a greater impact in places with insufficient buffer to allow landward migration. Increased storm intensity predicted under future climate change also threatens this system.

Source: NatureServe Explorer

Distribution

This system is restricted to the Gulf Coast of Texas.

Source: NatureServe Explorer

Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Shrub/sapling (tall & short)

Baccharis halimifolia

Herb (field)

Muhlenbergia capillaris, Paspalum vaginatum, Schizachyrium scoparium ssp. littorale, Spartina patens, Spartina spartinae, Sporobolus virginicus, Vigna luteola

Source: NatureServe Ecological System assessment

Ecologically Associated Animals (3)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Reptiles (2)

Common Name	Scientific Name	G-Rank
Saltmarsh Snake	Nerodia clarkii	G3G4
Mississippi Green Watersnake	Nerodia cyclopion	G5

Other (1)

Common Name	Scientific Name	G-Rank
Marsh Rice Rat	Oryzomys palustris	G5

Source: NatureServe Ecological System assessment

At-Risk Species Associated with this Ecosystem (1)

Species with conservation concern that are ecologically associated with this ecosystem type. G-Rank indicates global conservation status: G1 (critically imperiled) through G5 (secure). ESA status indicates U.S. Endangered Species Act listing.

Common Name	Scientific Name	G-Rank	ESA Status
Saltmarsh Snake	Nerodia clarkii	G3G4	--

Source: NatureServe Ecological System assessment

Component Associations (4)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

Name	G-Rank
Baccharis halimifolia Ruderal Shrubland	GNA	NatureServe
Muhlenbergia capillaris Grassland	G1	NatureServe
Spartina spartinae Grassland	G4	NatureServe
Spartina spartinae - Schizachyrium scoparium Grassland	G3	NatureServe

State Conservation Ranks (1)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

State	S-Rank
TX	SNR

Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.