Phytoplankton of the Chaco-pampean plain
This article summarizes the characteristics of phytoplankton of the Chaco-Pampean Plain between the Pilcomayo River (25º15’S; 57º45’W) and the Lower Salado River (31º39’S; 60º45’W) towards the Paraguay-Paraná system. This subtropical area has a climate gradient from east (wet) to west (arid)....
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| Autores principales: | , , |
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| Formato: | Artículo |
| Lenguaje: | Inglés |
| Publicado: |
E Schweizerbartsche Verlags
2021
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| Materias: | |
| Acceso en línea: | http://repositorio.unne.edu.ar/handle/123456789/30285 |
| Aporte de: |
| Sumario: | This article summarizes the characteristics of phytoplankton of the Chaco-Pampean Plain
between the Pilcomayo River (25º15’S; 57º45’W) and the Lower Salado River (31º39’S; 60º45’W)
towards the Paraguay-Paraná system. This subtropical area has a climate gradient from east (wet) to
west (arid). Rivers and streams have a seasonal regime, with fl oods in autumn and dry periods at the
end of winter. These hydrological fl uctuations appear to be the driving forces of the phytoplankton
community. During low waters (fl ow reduction and increase in salinity), diversity is reduced and
density of euryhaline species is increased. The highest algal development in this area was observed
during the extraordinary low water period of La Niña. In occasions of environmental stability and high
temperatures, water blooms of Anabaenopsis arnoldii, A. nadsonii and Nodularia harveyana have been
recorded.
The lenitic environments of the western region (arid) show marked fl uctuations in extension and depth
and may dry during periods of scarce precipitations. Phytoplankton density is low and represented by
small Chlorococcales and Euglenophyceae. Water blooms of Dolichospermum spp. and Cylindro spermopsis raciborskii are frequent. Shallow lakes and wetlands of the eastern region (wet), which have
presence of macrophytes and high organic matter, are dominated by Cryptophyceae, Chlorococcales
and a wide variety of species of Euglenophyceae and diatoms. The Ramsar Site called ‘Humedales
Chaco’ has the greatest diversity of species in this region. |
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