¿Son las planicies fluviales de la Cuenca del Plata, corredores de biodiversidad? Los amniotas como ejemplo

GIRAUDO, ALEJANDRO R.; ARZAMENDIA, VANESA

Humedales de Iberoamérica

Editado por el CYTED, Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo

Lugar: La Habana; Año: 2004; p. 157 - 170

We analized the function of the Plata basin rivers as biodiversity corridors, surveying tropical and subtropical amniotes vertebrates that increase their southern distributions throughout these rivers. We compared the hypothesis about the differential function between the Paraguay?Paraná axis and the Uruguay and Alto Paraná rivers, which may be corridors for Amazonian and Atlantic taxa respectivelly. We analyzed taxa distributional patterns by mean of 208 field samples throughout main rivers of the basin in Argentina, and some areas in Paraguay, Pantanal and southeast of Brazil and east of Bolivia. We quantified the distance that reach the taxa throughout the rivers from their general distribution border, established by means of our data and literature. A total of 176 taxa increase their distribution between 100 and 1,800 km ( x =483±277 km) on the  basin rivers. The majority of them have a wide tropical (77), Atlantic (53), Pantanal? Chaco (16), Amazonic (4) and Sudamazonic?Central South America (4) distributional patterns. A total of 75% of the Atlantic species reach higher latitudes throughout Uruguay and Alto Paraná rivers being absent in the Midlle Paraná river. A total of 88% of the last three mentioned distributional patterns reach higher latitudes throughout Paraguay?Paraná axis being absent in the Alto Paraná and Uruguay rivers. These patterns are discussed from an ecological, geographic and historical perspective. Several southern populations that are recorded throughout these rivers have differed with respect to the source populations and they have been described as new species or subspecies, showing the importance of this process in the evolution and diversification  of the regional and neotropical biotas. Despite of this, the gallery forest of these rivers has been poorly considered in conservation policies, showing serious deficiencies on protected areas and an increment in its fragmentation and deforestation rate.