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A0041 Ebenopsis ebano - Sabal mexicana / Cardiospermum corindum Riparian Scrub Alliance
Type Concept Sentence: This alliance includes riparian forests of the Rio Grande delta in south Texas and southeastern Mexico dominated or codominated by Ebenopsis ebano and Sabal mexicana.
Common (Translated Scientific) Name: Texas Ebony - Rio Grande Palmetto / Faux-persil Riparian Scrub Alliance
Colloquial Name: Texas Ebony - Rio Grande Palmetto Riparian Scrub
Hierarchy Level: Alliance
Type Concept: This alliance includes subtropical riparian forests of the Rio Grande delta in south Texas and southeastern Mexico. These forests are most often associated with resacas (low-lying areas formed by old river channels), levees, and floodplain terraces of the Rio Grande delta. This alliance is extremely restricted, remaining only as fragmented stands within an agricultural landscape. It is characterized by a mixture of subtropical and temperate tree species. Canopy dominants and codominants include Ebenopsis ebano and Sabal mexicana. Associated canopy species can include Ehretia anacua, Leucaena pulverulenta, Phaulothamnus spinescens, Fraxinus berlandieriana, Celtis laevigata, Ulmus crassifolia, and Prosopis glandulosa. Tillandsia usneoides may occur as an epiphyte in the canopy. Undergrowth may be absent to dense, with a tangle of vines, shrubs, and fallen trees. Typical shrubs include Sideroxylon celastrinum, Havardia pallens, Zanthoxylum fagara, Condalia hookeri, Ziziphus obtusifolia, Malvaviscus arboreus var. drummondii, and Celtis ehrenbergiana. Fire and periodic flooding are thought to be critical factors to maintain Sabal mexicana forests. Forests in this alliance are known from a few sites south of Brownsville, Texas, in the lower Rio Grande Valley. Similar vegetation once was found in Mexico and probably is now totally eliminated.
Diagnostic Characteristics: This riparian forest alliance is characterized by a mixture of subtropical and temperate species dominated or codominated by Ebenopsis ebano and Sabal mexicana occurring in the Rio Grande delta in south Texas and southeastern Mexico.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance is centered on the Rio Grande delta of the Gulf of Mexico. It is a mixture of subtropical and temperate species. It is also fraught with extreme loss of occurrences (<10% of former extent of remains), and a lack of good range-wide plot data. Data gaps could represent undescribed associations. Its concept and group placement need a broader review in the context of other temperate and subtropical vegetation that could have similar composition, especially in Mexico. No character species have been identified, and while there could be some differential species, they are not the dominants. Many species in this alliance have very limited distribution in the U.S.; however, their distribution in Mexico has not been assessed. This vegetation once occupied a large delta region and the mixture of temperate, desert, and subtropical species appears unique. While these forests show strong subtropical floristic affinities, the area''s subtropical status is disputed.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance is characterized by subtropical forests. Undergrowth may be absent to dense, with a tangle of vines, shrubs, and fallen trees.
Floristics: Subtropical forests in extreme southern Texas, along the lower Rio Grande, with Ebenopsis ebano (= Pithecellobium ebano) as a codominant. Associated species can include Ehretia anacua, Leucaena pulverulenta, Phaulothamnus spinescens, Sideroxylon celastrinum, Havardia pallens, Zanthoxylum fagara, Condalia hookeri, Celtis ehrenbergiana (= Celtis pallida), Ziziphus obtusifolia, and Prosopis glandulosa. This alliance also includes subtropical forests of southern Texas dominated or codominated by Sabal mexicana. Associated species can include Fraxinus berlandieriana, Celtis laevigata, Ulmus crassifolia, Ebenopsis ebano, Leucaena pulverulenta, and Ehretia anacua. Tillandsia usneoides may occur as an epiphyte in the canopy. Undergrowth may be absent to dense, with a tangle of vines, shrubs, and fallen trees. Typical shrubs include Havardia pallens, Sideroxylon celastrinum (= Bumelia celastrina), Malvaviscus arboreus var. drummondii (= Malvaviscus drummondii), and Celtis ehrenbergiana.
Dynamics: This alliance is extremely restricted, much of the original acreage having been cleared for row crops and pasture.
Environmental Description: This alliance occurs in an area of subtropical climate with over 300 frost-free days per year and average precipitation of 66 cm per year. These forests occur on deep, well-drained soils (silts and sands) of the Rio Grande delta, and are most often associated with mesic resaca banks, low-lying areas formed by old river channels. Fire and periodic flooding are thought to be critical factors to maintain Sabal mexicana forests.
Geographic Range: This alliance is known only from the lower Rio Grande Valley of Texas and Tamaulipas, Mexico.
Nations: MX,US
States/Provinces: MXTAM, TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.898954
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.3 Temperate Flooded & Swamp Forest Formation | F026 | 1.B.3 |
| Division | 1.B.3.Nd Western North American Interior Flooded Forest Division | D013 | 1.B.3.Nd |
| Macrogroup | 1.B.3.Nd.2 Interior Warm & Cool Desert Riparian Forest Macrogroup | M036 | 1.B.3.Nd.2 |
| Group | 1.B.3.Nd.2.a Rio Grande Palmetto - Texas Ebony - Cedar Elm Tamaulipan Riparian Scrub Group | G549 | 1.B.3.Nd.2.a |
| Alliance | A0041 Texas Ebony - Rio Grande Palmetto / Faux-persil Riparian Scrub Alliance | A0041 | 1.B.3.Nd.2.a |
| Association | CEGL002054 Texas Ebony - Knockaway / Brazilian Bluewood Riparian Forest | CEGL002054 | 1.B.3.Nd.2.a |
| Association | CEGL002056 Rio Grande Palmetto - Texas Ebony Riparian Forest | CEGL002056 | 1.B.3.Nd.2.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Clover, E. U. 1937. Vegetational survey of the Lower Rio Grande Valley, Texas. Madrono 4:41-55, 77-100.
- Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
- Diamond, D., B. Amos, T. Cook, R. Edwards, W. Elliot, R. Evans, and K. Kennedy. 1992. Endangered, threatened, and watchlist of natural communities of Texas. Texas Organization for Endangered Species. Austin, TX. 14 pp.
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Wynd, F. L. 1944. The geologic and physiographic background of the soils in the lower Rio Grande Valley, Texas. The American Midland Naturalist 32:200-235.