IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Salt leaching leads to drier soils in disturbed semiarid woodlands of central Argentina
Autor/es:
MARCHESINI, V.A.; FERNÁNDEZ, ROBERTO J.; JOBBÁGY, E.G.
Revista:
OECOLOGIA
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012
ISSN:
0029-8549
Resumen:
Disturbances in semiarid environments have revealed a strong connection between water, salt andvegetation dynamics highlighting how the alteration of water fluxes can drive salt redistribution process and longterm environmental degradation. Here, we explore to what extent the reciprocal effect, that of salt redistribution on water fluxes, may play a role in dictating environmentalchanges following disturbance in dry woodlands. We assessed salt and water dynamics comparing soil-solution electrical conductivity, chloride concentration, soil water content (SWC) and soil matric and osmotic water potential (Wm, Wos) between disturbed and undisturbed areas. Alarge pool of salts and chlorides present in undisturbed areas was absent in disturbed plots, suggesting deep leaching. Unexpectedly, this was associated with slight but consistently lower SWC in disturbed versus undisturbed situations during two growing seasons. The apparent paradox of increased leaching but diminishing SWC after disturbance can be explained by the effect of native salt lowering Wos enough to prevent full soil drying. Underdisturbed conditions, the onset of deep drainage and salt leaching would raise Wos allowing a decline of Wm and SWC. Soil water storage seems to be modulated by thepresence (under natural conditions) and partial leaching (following selective shrub disturbance) of large salt pools. This counterintuitive effect of disturbances may be important in semiarid regions where deep soil salt accumulation is a common feature. Our results highlight the importance of water?salt?vegetation coupling for the understanding and management of these systems.