Resumen

CASCO, Sylvina Lorena  y  NEIFF, Juan José. How are the roots distributed in the riverine forests of Salix humboldtiana and Tessaria integrifolia of low Parana?. INCI [online]. 2006, vol.31, n.8, pp.605-610. ISSN 0378-1844.

The riverine forests dominated by Salix humboldtiana Willd. and Tessaria integrifolia Ruiz et Pav. grow in silt and sand deposited in bars and the Paraná River floodplain. In contrast with terrestrial ecosystems, the soil of the recent islands is originated by the superposition of layers with different grain size, related with the magnitude of the each flood. In these islands, the difference between soil horizons represents the horizontal movements of the river flow. The abundance of absorption roots in soil profiles of islands with different flood period owing to the topographical location was studied to determine possible differences in the vertical distribution of the roots. The samples were taken with a core sampler from the surface to 1.3m depth. The roots were extracted from the soil and dried off in furnace at 105°C until dry weight. There was no relationship found between the depth of each horizon and the concentration of absorption roots. The texture of soil horizons depends on the frequency and intensity of the floods in each site. There was a low correlation between the concentration of roots and the duration and intensity of the floods in each place, possibly because these trees are very tolerant to floods and droughts, a fact that could justify the poorly defined pattern of root stratification.

Palabras clave : Bosques Ribereños ; Raíces ; Régimen de Pulsos ; Río Paraná ; Suelo .