Included here is the pampas and campos regions of South America and includes the central parts of Argentina, all of Uraguay and the southern extremities of Brazil.

Pampean Saltmarsh

The Pampean saltmarshes of central Argentina can be divided into four major community types or zones influenced by factors such as elevation, levels of flooding and salinity.  At the lowest levels where flooding levels are high and salinity relatively low the vegetation is dominated by Spartina densiflora but with increasing elevation and rising salinity the three other vegetation types range through a Distichlis spicata zone, a Distichlis scoparia zone and finally at the highest elevations a Stipa trichotoma-Stipa tenuissima zone. The highest diversity was found at the highest elevations in the Stipa trichotoma-Stipa tenuissima zone and progressively declined toward the stands of Spartina. The following provides brief descriptions of each saltmarsh type.

Spartina densiflora Salt marsh
This is tall grassland community dominated by hemicryptophytes and therophytes. Associated species include Diplachne uninervia, Echinochloa helodes, Euphorbia serpens, Polygonum hydropiperoides and Rumex crispus.

Distichlis spicata Salt marsh
This is a short grassland community with many geophytes. Associated species include Baccharis juncea, Cressa truxillensis, Frankenia pulverulenia, Heliotropium curassavicum, Polygonum stypticum, Sarcocornia perennis, Scirpus americanus, Sesuvium portulacastrum, Sporobolus indicus and Suaeda patagonica.

Distichlis scoparia Salt marsh
This is a dense short grassland community dominated by geophytes and hemicryptophytes. Associated species include Ammi viznaga, Apium commersonii, Aster squamatus, Centaurium pulchellum, Chaetotropis elongatus, Chloris berroi, Chloris halophila, Ciclospermum leptophyllum, Cynodon dactylon, Cyperus aggregatus, Cyperus corymbosus, Galactia latisiliqua, Gamochaeta spicata, Hordeum stenostachys, Hypochoeris chillensis, Hypochoeris microcephala, Juncus capillaceous, Kochia scoparia, Lepidium spicatum, Limonium brasiliense, Medicago lupulina, Muhlenbergia asperifolia, Oxalis chrysantha, Oxypetalum solanoides, Pappophorum philipphianum, Paspalum vaginatum, Plantago myosurus, Portulaca gilliesii, Spergula romosa, Verbena gracilescens, Verbena montevidensis and the Argentinian endemic Atriplex undulata.

Stipa trichotoma-Stipa tenuissima Salt marsh
This is tall grassland community supporting many hemicryptophytes and therophytes. Associated species include Ambrosia tenuifolia, Ammi majus, Anthemis cotula, Aristida spegazzini, Ascelpias mellodora, Baccharis pingraea, Baccharis stenophylla, Baccharis ulicina, Bidens subalternans, Boopis anthemoides, Bothriochloa springfieldii, Briza subaristata, Bromus brevis, Bromus catharticus, Carduus nutans, Cenchrus myosuroides, Cenchrus pauciflorus, Chenopodium ambrosioides, Chenopodium multifidum, Clematis montevidensis,Commelina diffusa,  Conyza bonariensis, Daucus pusillus, Desmanthus depressus, Digitaria californica, Digitaria sanguinalis, Eragrostis lucens, Eryngium horrdum, Euphorbia portulacoides, Eustachya retusa, Gamochaeta filaginea, Glandularia platensis, Gnaphalium gaudichaudianum, Halimolobos montanus, Lolium multiflorum, Nierembergia aristata, Oenothera affinis, Panicum bergii, Paspalum notatum, Pfaffia gnaphalioides, Physalis viscosa, Piptochaetium montevidense, Plantago tomentosa, Relbunium richardianum, Rhynchosia senna, Schizachyrium condensatum, Senecio pampeanus, Setaria parviflora, Sisyrinchium chilense, Stipa brachychaeta, Stipa eriostachya, Stipa neesiana, Stipa papposa, Turnera pinnatifida, Verbascum virgatum, Verbena bonariensis, Vicia pampicola, Wahlenbergia linarioides and the Argentinian endemics Descurainia argentina, Ledidium parodii, Prosopis humilis, Sphaeralcea crispa and Sporobolus rigens.

References

Cantero, J. J., Leon, R., Cisneros, J. M. & Cantero, A. 1998. Habitat structure and vegetation relationships in central Argentina saltmarsh landscapes. Plant Ecology, 137: 79-100.

Cantero, J. J., Cisneros, J. M., Zobel, M. & Cantero, A. 1998. Environmental relationships of vegetation patterns in saltmarshs of central Argentina. Folia Geobotanica, 33: 133-145.