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A3168 Tamaulipan Caliche Grassland Alliance
Type Concept Sentence: This grassland alliance, characterized by a variety of grasses such as Aristida purpurea, Bouteloua curtipendula, Bouteloua hirsuta, Bouteloua radicosa, Cenchrus spinifex, Elionurus tripsacoides, Heteropogon contortus, Paspalum setaceum, Schizachyrium littorale, Trachypogon spicatus, Tridens texanus, and Tridens muticus, occurs on shallow sandy loam soils with a caliche hardpan subsoil in the Tamaulipan region of south Texas and northeastern Mexico.
Common (Translated Scientific) Name: Tamaulipan Caliche Grassland Alliance
Colloquial Name: Tamaulipan Caliche Grassland
Hierarchy Level: Alliance
Type Concept: This grassland alliance occurs as patches smaller than 100 acres on shallow sandy loam soils with a caliche hardpan subsoil in the Tamaulipan region of south Texas and northeastern Mexico. Characteristic grasses include Aristida purpurea, Bouteloua curtipendula, Bouteloua hirsuta, Bouteloua radicosa, Brachiaria ophryodes, Cenchrus spinifex, Elionurus tripsacoides, Heteropogon contortus, Paspalum setaceum, Schizachyrium littorale, Trachypogon spicatus, Tridens texanus, and Tridens muticus. Perennial forbs are conspicuous and include species such as Heliotropium confertifolium, Melampodium cinereum, Simsia calva, Acalypha radians, Cnidoscolus texanus, Galphimia angustifolia, Hermannia texana, Croton capitatus, Rhynchosia americana, and Dalea nana. Surrounding the grasslands is a matrix of calcareous shrublands. Shrubs and subshrubs are scattered and sometimes coalesce into larger areas, and include species such as Calliandra conferta, Krameria ramosissima, Calliandra biflora, Chamaecrista greggii, Mandevilla lanuginosa, Prosopis glandulosa, Zanthoxylum fagara, Cordia boissieri, and Condalia hookeri.
Diagnostic Characteristics: This alliance consists of grassland openings occurring over sandy loams with a caliche hardpan in the Tamaulipan thornscrub region of south Texas and northeastern Mexico.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This grassland alliance is described from very little information. There may be undescribed associations related to this alliance. More information is needed to flesh out detailed floristic, environment, and range, but few high-quality examples are known.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: These small-patch grasslands are less than 40 ha in area and are dominated by perennial grasses often with sparse low shrubs within a mosaic of thornscrub.
Floristics: These grasslands are known to occur within a mosaic of calcareous shrublands. Johnston (1963) describes them as grassland patches (the largest of which are 50-100 acres in extent) within a shrubland matrix. Characteristic grasses in Texas may include Aristida purpurea, Bouteloua hirsuta, Elionurus tripsacoides, Trachypogon spicatus, Heteropogon contortus, Bouteloua curtipendula, Schizachyrium littorale, Tridens texanus, and Tridens muticus. Brachiaria ophryodes and Bouteloua radicosa are also noted from occurrences in Mexico. Shrubs and subshrubs are scattered and sometimes coalesce into larger areas, and include species such as Calliandra conferta, Krameria ramosissima, Calliandra biflora, Mandevilla lanuginosa (= Macrosiphonia lanuginosa), Chamaecrista greggii (= Cassia greggii), Coursetia axillaris, Lippia graveolens, Turnera diffusa, Prosopis glandulosa, Zanthoxylum fagara, Cordia boissieri, and Condalia hookeri (Johnston 1963, Elliott 2011). Perennial forbs are conspicuous and include species such as Heliotropium confertifolium, Melampodium cinereum, Simsia calva, Acalypha radians, Boerhavia coccinea, Chamaecrista greggii, Chamaecrista flexuosa var. texana (= Cassia texana), Cnidoscolus texanus, Galphimia angustifolia, Hermannia texana, Croton capitatus, Rhynchosia americana, and Dalea nana. Composition varies according to the depth to the caliche subsoil. Many sites may currently be occupied by non-native grasses such as Pennisetum ciliare and Bothriochloa ischaemum var. songarica, though invasion by these species is not observed in Mexican occurrences (Chris Best pers. obs.). U.S. occurrences lack some of the species present in the Mexican occurrences.
Dynamics: Occurrences are naturally small with the larger brush-free stands only 50-100 acres in extent. Larger areas occur as mosaics of grassland mixed with brush mottes (Johnston 1963). Fire, climate, native grazing and edaphic factors all likely played a roll historically in maintaining an open structure in this vegetation.
Environmental Description: This alliance occurs on shallow sandy loam soils with a caliche hardpan subhorizon (Johnston 1963). It is described from the vicinity of Loreto in Tamaulipas, Mexico, and an area of sand veneer over caliche outcrop in northern Hidalgo and Starr counties where the edge of the Texas sandsheet passes over the Goliad Formation (Elliott 2011). In Texas, soils are a reddish sandy loam about 0.3 m in depth or less - a relatively thin veneer of eolian sand over caliche substrate.
Geographic Range: These grasslands occur on relatively level sites atop the Goliad Formation in south Texas, and in the vicinity of Loreto in Tamaulipas, Mexico.
Nations: MX,US
States/Provinces: MXTAM, TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899293
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 3 Desert & Semi-Desert Class | C03 | 3 |
| Subclass | 3.A Warm Desert & Semi-Desert Woodland, Scrub & Grassland Subclass | S06 | 3.A |
| Formation | 3.A.2 Warm Desert & Semi-Desert Scrub & Grassland Formation | F015 | 3.A.2 |
| Division | 3.A.2.Na North American Warm Desert Scrub & Grassland Division | D039 | 3.A.2.Na |
| Macrogroup | 3.A.2.Na.1 Honey Mesquite - Spiny Hackberry / Multi-flower Rhodesgrass Tamaulipan Scrub & Grassland Macrogroup | M130 | 3.A.2.Na.1 |
| Group | 3.A.2.Na.1.b Multi-flower Rhodesgrass - Cane Bluestem - Texas Prickly-pear Grassland Group | G100 | 3.A.2.Na.1.b |
| Alliance | A3168 Tamaulipan Caliche Grassland Alliance | A3168 | 3.A.2.Na.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Loreto caliche-sand grasslands (Johnston 1963)
> South Texas: Caliche Grassland (6707) [CES301.989] (Elliott 2011)
> South Texas: Caliche Grassland (6707) [CES301.989] (Elliott 2011)
- Elliott, L. 2011. Draft descriptions of systems, mapping subsystems, and vegetation types for Phases I, II, III, and IV. Unpublished documents. Texas Parks and Wildlife Ecological Systems Classification and Mapping Project. Texas Natural History Survey, The Nature Conservancy of Texas, San Antonio.
- 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.
- Johnston, M. C. 1963. Past and present grasslands of southern Texas and northeastern Mexico. Ecology 44:456-464.