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A1348 Polygonum spp. - Echinochloa spp. - Distichlis spicata Wet Meadow Alliance
Type Concept Sentence: This wetland community is found in the central Great Plains of the United States where it occurs in shallow depressions with annual herbaceous graminoids and forbs, mostly <1 m tall, dominating the exposed mudflats.
Common (Translated Scientific) Name: Knotweed species - Cockspur Grass species - Saltgrass Wet Meadow Alliance
Colloquial Name: Knotweed - Cockspur Grass - Saltgrass Wet Meadow
Hierarchy Level: Alliance
Type Concept: This wetland community is found in the central Great Plains of the United States. Annual herbaceous graminoids and forbs, mostly <1 m tall, dominate the exposed mudflats, and species composition and extent of the community fluctuate from site to site and year to year. In Nebraska, graminoids include Cyperus acuminatus, Eleocharis engelmannii, and Echinochloa muricata, and forbs include Bacopa rotundifolia, Coreopsis tinctoria, Elatine rubella, Heteranthera limosa, Limosella aquatica, Lindernia dubia, Mollugo verticillata, Polygonum pensylvanicum, Polygonum lapathifolium, Rumex stenophyllus, and Sagittaria calycina. In Kansas, graminoids include Hordeum jubatum, and forbs include Ambrosia grayi, Symphyotrichum subulatum, and Chenopodium berlandieri. The frequent water fluctuations and thick claypan prevent establishment of most perennial hydrophytes, such as Schoenoplectus spp. and Typha spp. It occurs in shallow depressions on gently sloping topography. Soils are deep to moderately deep loams or clay loams underlain by a dense clay sublayer. Sites flood for some part of the growing season but do not stay flooded for long periods.
Diagnostic Characteristics: This alliance is found on fine soils over claypans where flooding occurs for part of the growing season but sites dry out enough to prevent most wetland vegetation from growing. Dominant species vary with time of year and amount of flooding but typically include Distichlis spicata, Echinochloa muricata, Polygonum lapathifolium, and Polygonum pensylvanicum.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance currently has only one association. There is a related association, ~Polygonum pensylvanicum - Polygonum lapathifolium Marsh (CEGL002277)$$, in a different alliance that might merit merging into a single alliance. The hydroperiod and some associated species are different so they are placed in separate alliances for now. Rolfsmeier and Steinauer (2010) note that stands in northwestern Nebraska may or may not belong to this type because they are associated with artificial impoundments. The global name for this type is weak, and better characteristic species are needed to name it. It is unclear whether stands from Nebraska, Kansas, and Oklahoma really fit into the same type.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance is characterized by annual graminoids and forbs less than 1 m tall. Vegetation cover is variable. Recently exposed sites tend to have little vegetation and the cover expands as the annual plants germinate.
Floristics: Annual herbaceous graminoids and forbs mostly less than 1 m tall dominate the exposed mudflats of this alliance. Species composition and extent of stands vary from year to year. Coreopsis tinctoria, Echinochloa spp., Eleocharis engelmannii, Lindernia dubia, Polygonum spp., and Rumex stenophyllus are typical species of this alliance. In Nebraska, graminoids include Cyperus acuminatus, Eleocharis engelmannii, and Echinochloa muricata, and forbs include Bacopa rotundifolia, Coreopsis tinctoria, Elatine rubella, Heteranthera limosa, Limosella aquatica, Lindernia dubia, Mollugo verticillata, Polygonum pensylvanicum (= Polygonum bicorne), Polygonum lapathifolium, Rumex stenophyllus, and Sagittaria calycina. In Kansas, graminoids include Hordeum jubatum, and forbs include Ambrosia grayi, Symphyotrichum subulatum (= Aster subulatus), and Chenopodium berlandieri. The frequent water fluctuations and thick claypan prevent establishment of most perennial hydrophytes, such as Schoenoplectus spp. (= Scirpus spp.) and Typha spp. In sites which have been modified to hold water longer, i.e., drainage ditches and re-use pits, perennials such as Eleocharis palustris and Marsilea vestita may dominate. The frequent water fluctuations and thick claypan prevent establishment of most perennial hydrophytes typical of pond marshes.
Dynamics: The cycle of flooding and drying is important in maintaining stands of this alliance. The widely varying hydrologic conditions prevent perennial species from becoming abundant.
Environmental Description: Stands of this alliance occur in shallow depressions in nearly level ground. Soils are silty clay loam underlain by a claypan. These areas are temporarily or sometimes seasonally flooded by ponded rainwater and surface runoff. Sites dry out by mid to late summer in all but the wettest years.
Geographic Range: This alliance is found in the central Great Plains in Nebraska and Kansas and possibly Oklahoma.
Nations: US
States/Provinces: KS, NE, OK?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899116
Confidence Level: Moderate
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 | A1348 Knotweed species - Cockspur Grass species - Saltgrass Wet Meadow Alliance | A1348 | 2.C.4.Nd.5.e |
| Association | CEGL002039 Smartweed species - Cockspur Grass species - Saltgrass Playa Lake Wet Meadow | CEGL002039 | 2.C.4.Nd.5.e |
Concept Lineage: This alliance has just one association from old A.1348 (with edits).
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- 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.
- Rolfsmeier, S. B., and G. Steinauer. 2010. Terrestrial ecological systems and natural communities of Nebraska (Version IV - March 9, 2010). Nebraska Natural Heritage Program, Nebraska Game and Parks Commission. Lincoln, NE. 228 pp.