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A1238 Panicum obtusum Wet Meadow Alliance
Type Concept Sentence: This alliance is found in the southern Great Plains and northern Chihuahuan Desert on heavy, mesic soils in depressions, along streams, and in playa basins with abundant Panicum obtusum.
Common (Translated Scientific) Name: Vine-mesquite Wet Meadow Alliance
Colloquial Name: Vine-mesquite Wet Meadow
Hierarchy Level: Alliance
Type Concept: This alliance is found in the southern Great Plains and northern Chihuahuan Desert on mesic sites. Mid grasses are characteristic and typically dominate though short grasses can be abundant on some sites. Vegetation cover is typically moderate but is often more dense than surrounding drier vegetation. Panicum obtusum is consistently abundant or dominant. Bouteloua dactyloides, Helianthus ciliaris, Panicum hirsutum, and Pascopyrum smithii are common to abundant. Panicum hallii can be common, particularly on degraded sites. It occurs on heavy, mesic soils in depressions, along streams, and in playa basins.
Diagnostic Characteristics: This alliance is characterized by abundant Panicum obtusum in playa, riparian, or basin settings.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: There is limited information for the three associations making up this alliance. Further review of the associations and the alliance is warranted. Due to the limited information for the component associations, it is difficult to determine if this alliance really fits in ~Great Plains Playa & Rainwater Basin Wetland Group (G136)$$ or if it is better placed in a mesic grassland (riparian?) group.
Some stands described by Bourgeron et al. (1993b) have only 1-3% Panicum obtusum. A more appropriate alliance classification may be a Panicum obtusum - Panicum hallii - Panicum hirsutum Herbaceous Alliance.
Some stands described by Bourgeron et al. (1993b) have only 1-3% Panicum obtusum. A more appropriate alliance classification may be a Panicum obtusum - Panicum hallii - Panicum hirsutum Herbaceous Alliance.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation included in this alliance has a moderately dense graminoid layer dominated by medium-tall perennial bunch grasses. Short grasses and forbs may codominate. Scattered cacti may be present.
Floristics: Stands in this alliance have a sparse to moderately dense graminoid layer (20-50% cover) of medium-tall perennial bunchgrasses and are usually dominated by Panicum obtusum, Panicum hallii, or Panicum hirsutum. The shortgrass Bouteloua dactyloides (= Buchloe dactyloides) and the perennial forb Helianthus ciliaris may codominate some stands. Characteristic graminoids include Bouteloua gracilis, Bouteloua curtipendula, Cyperus spp., Eragrostis intermedia, Scleropogon brevifolius, and the annual Aristida adscensionis. The usually sparse forb layer may reach 20% cover. Common forbs include Grindelia squarrosa, Hoffmannseggia glauca, Proboscidea spp., Solanum spp., Sphaerophysa salsula, and Zinnia grandiflora. Scattered Opuntia phaeacantha are present in some stands.
Dynamics: No Data Available
Environmental Description: Grasslands included in this alliance occur in swales and playas in the southern Great Plains and the Chihuahuan Desert. Elevations range from 1300-1600 m. Climate is arid to semi-arid with hot summers. Freezing temperatures may occur during winter. Mean annual precipitation decreases from Oklahoma to southwestern New Mexico. It is approximately 22 cm at the Jornada Experimental Range, but is highly variable with drought not uncommon. Annual precipitation is distributed bimodally with about one-third occurring in late winter and two-thirds in July through October, often as high-intensity convective storms. These grasslands commonly occur in swales and playas, and along drainages that dissect the plains, piedmonts, and mesas. Sites are nearly level to gently sloping and receive excess runoff from the surrounding landscape. Soils are deep, silty clays, often gravelly. Soils are derived from gravelly or silty alluvium. Ground cover is relatively low. Bourgeron et al. (1993b) described stands where mean cover of bare soil, rock, litter, and basal vegetation ranged from 60-90%, 0-30%, 0-1% and 10-30%, respectively. Stands are surrounded by a matrix of desert shrublands, Quercus savannas, and upland grasslands.
Geographic Range: This alliance is found in the southern Great Plains and northern Chihuahuan Desert. It may occur as far south as southeastern Arizona and in Mexico in northern Chihuahua and Coahuila.
Nations: MX?,US
States/Provinces: AZ?, CO, MXCHH?, MXCOA?, NM, OK, TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899092
Confidence Level: Low
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.C Shrub & Herb Wetland Subclass | S44 | 2.C |
| Formation | 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation | F013 | 2.C.4 |
| Division | 2.C.4.Nd Eastern North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division | D323 | 2.C.4.Nd |
| Macrogroup | 2.C.4.Nd.5 Prairie Cordgrass - Cattail species - Bulrush species Great Plains Marsh, Wet Meadow, Shrubland & Playa Macrogroup | M071 | 2.C.4.Nd.5 |
| Group | 2.C.4.Nd.5.e Western Wheatgrass - Vine-mesquite - Buffalograss Playa & Rainwater Basin Wetland Group | G136 | 2.C.4.Nd.5.e |
| Alliance | A1238 Vine-mesquite Wet Meadow Alliance | A1238 | 2.C.4.Nd.5.e |
| Association | CEGL001573 Vine-mesquite - Buffalograss Wet Meadow | CEGL001573 | 2.C.4.Nd.5.e |
| Association | CEGL001574 Vine-mesquite - Texas Blueweed Wet Meadow | CEGL001574 | 2.C.4.Nd.5.e |
| Association | CEGL001575 Vine-mesquite - Hall''s Panicgrass Wet Meadow | CEGL001575 | 2.C.4.Nd.5.e |
Concept Lineage: This alliance contains three associations from old A.1238.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Panicum obtusum herbaceous alliance (Hoagland 1998a)
- Bourgeron, P. S., L. D. Engelking, H. C. Humphries, E. Muldavin, and W. H. Moir. 1993b. Assessing the conservation value of the Gray Ranch: Rarity, diversity and representativeness. Unpublished report prepared for The Nature Conservancy by the Western Heritage Task Force, Boulder, CO. (Volume I and II).
- Bourgeron, P. S., L. D. Engelking, H. C. Humphries, E. Muldavin, and W. H. Moir. 1995a. Assessing the conservation value of the Gray Ranch: Rarity, diversity and representativeness. Desert Plants 11(2-3):3-68.
- 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.
- Hoagland, B. W. 1998a. Classification of Oklahoma vegetation types. Working draft. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 43 pp.