Southern South America: Eastern Argentina

This flooded savanna, fed by the Paraná river, is located in Argentina. Defined by a almost subtropical temperatures usually found much farther north, this region is rich in flora and fauna that is uncharacteristic of its surrounding regions. A number of national parks protect this habitat, which contains three endemic bird areas. The main threat to this ecoregion is the building of damsand dykes, while hunting, urban expansion, and pollution constitute other threats.

  • Scientific Code
  • Ecoregion Category
  • Size
    15,000 square miles
  • Status
  • Habitats

Location and General Description
This region includes the floodplains of the middle and lower Paraná river and its tributary the Paraguay river. The southern section includes the Paraná delta and the la Plata river basin. The landscape of this region is represented by low islands that flood and are delimited by the lateral branches and major flows of the great rivers and extensive coastal lowlands.

The permanent presence of large bodies of water create local climatic effects with high ambient humidity and mitigate extreme daily and seasonal temperatures, allowing for the presence of communities and species typical of the humid subtropical regions of the country’s northeast.

The vegetation in this region consists of forest and shrublands in slender coastal strips on albardones [land emerging from the water]; scrublands and pastures on the islands in open waters; hydrophilic and aquatic communities on the shores of rivers and channels; and interior island lagoons.

The forests consist primarily of Salíx humboldtiana (sauce criollo or sauce colorado), Tessaria intergrifolia (aliso), Erythrina crista-galli (ceibo), etc. Aquatic communities include camalotes, primarily of the genus Eichhornia and Reussia, onagraceae like Victoria cruziana (irupé) with large plate-shaped leaves and white flowers with many petals; we also find Cyperus giganteus (pirí), Typha latifolia and T. Domingensis (totoras) and the beautiful blue-flowered pontederiacea Pontederia lanceolata (cucharero) (Cabrera 1976).

Biodiversity Features
This ecoregion is very rich in species. Among endemic, rare and endangered species are found the rana trepadora isleña (Argenteophyla siemersi), ciervo de los pantanos (Blastoceros dichotomus), pajonalera pico recto (Limnornis rectirostris), lobito de río (Lontra longicaudis) and carpincho (Hydrochaeris hydrochaeris) (Chebez 1988; Bertonatti and González 1992; Chebez 1994; García Fernández et al. 1997). The International Council for Bird Preservation (ICBP 1992) points to this region as one of the most important in terms of the presence of endemic bird species that according to the council number three.

Fish perhaps define the most interesting and diverse group in this region with more than 300 species with a predominance of characiforms and siluriforms (Canevari et al. 1998).

Among fauna, we find the rana trepadora isleña (Argenteophyla siemersi), ranita de las cardas (Hyla x-signata eryngiophila); among reptiles we can mention the culebra acuática manchada (Helicops leopardinus), culebra verde (Philodryas aestivus), tortuga de arroyo (Phrynops hilarii) and tortuga de cuello serpiente (Hidromedusa tectifera). Among birds we find the biguá (Phalacrocórax olivaceus), hocó colorado (Tigrisoma lineatum), lechuzón orejudo (Asio clamator), martín pescador chico (Chloroceryle americana), águila negra (Buteogallus urubitinga), gavilán común (Buteo magnirostris), pava de monte (Penélope obscura), carpintero bataraz (Picoides mixtus), espinero grande (Phacellodomus ruber), zorzal colorado (Turdus rufiventris), pajonalera pico recto (Limnornis rectirostris), etc. Some mammals in the region are the comadrejita ágil (Thylamys agilis), coipo (Myocastur coypus), ciervo de los pantanos (Blastoceros dichotomus), rata de pajonal (Scapteromys acuaticus), carpincho (Hydrochaeris hydrochaeris), lobito de río (Lontra longicaudis), etc.

Species of economic importance in the region include fish such as the surubíes (Pseudoplatystoma coruscans and P. fasciatum), manguruyú (Paulicea lukteni), dorado (Salminus maxillosus) and pirapitá (Brycon orbiginianus); these are important for sport fishing and are a great tourist attraction. We also find species for consumption and processing such as the sábalo (P. platensis), pearly clams for dressmaking materials and personal adornment, processing of skins and to a lesser extent meat from Myocastur coypus, L. longicaudis and Hydrochaeris hydrochaeris and processing of hides from Caiman sp and Tupinambis teguixin (Canevari et al, 1998).

Current Status
Among the Natural Reserves existing in this ecoregion we can mention the follow: Cayastá Provincial Reserve, Del Medio-Los Caballos Provincial Reserve, Colonia Benitez Strict Natural Reserve and Vire-Pitá Provincial Reserve.

Types and Severity of Threats
Large infrastructure projects such as dykes, dams, waterways, roads, etc. represent a great threat to the flora and fauna of Argentina. In the case of this region, we should add petroleum and mining operations, agriculture, urban expansion, pollution, habitat fragmentation and poorly-managed tourism. Commercial hunting and poaching also threaten wildlife as illegal shipments of hides and skins, in violation of established quotas and/or involving the hunting of prohibited species, are often detained.

Justification of Ecoregion Delineation
The deliniations for the Paraná Flooded Savanna were derived from Daniele and Natenzon (1994), and linework follows their classification of "Delta e Islas de Paraná (delta and islands of the Paraná River)" region. Other resources consulted include Cabrera (1976) and Morello (1968).

Bertonatti, C.Y.F. González. Lista de Vertebrados Argentinos Amenazados de Extinción. FVSA. 33pp.

Cabrera, A.L. 1976. Regiones Fitogeográficas de Argentina. Enciclopedia Argentina de Agricultura y Jardinería. Tomo II. Fascículo I. Editorial ACME S.A.C.I. 85pp.

Canevari P., D.E. Blanco, E. Bucher, G. Castro e I. Davidson. 1998. Los Humedales de la Argentina. Clasificación, situación actual, conservación y legislación. Wetlands International. Publicación Nº 46. 208pp.

CIPA 1992. Putting biodiversity the map, priority areas for global conservation.

Chebez, J. C. 1988. El deterioro de la Fauna. Capítulo VI del libro El deterioro del Ambiente en la Argentina (suelo, agua, vegetación, fauna). FECIC. 497pp

Chebez, J.C. 1994. Los que se van. Albatros. 604pp

Daniele, C., and C. Natenzon. 1994. Regiones Naturales de la Argentina. Draft map. Argentina National Parks Department, Buenos Aires, Argentina.

García Fernández, J.J., R. A. Ojeda, R. M. Fraga, G.B. Díaz, R.J. Baigún. 1997.Mamíferos y aves amenazados de la Argentina. FUCEMA, SAREM, AO del Plata, APN. 221pp.

Morello, J. 1968. La vegetación de la República Argentina, No. 10: Las grandes unidades de vegetación y ambiente del Chaco Argentino. Buenos Aires, Argentina.

Prepared by: Claudia Dellafiore
Reviewed by: In process