Salt leaching leads to drier soils in disturbed semiarid woodlands of Central Argentina

Disturbances in semiarid environments have revealed a strong connection between water, salt and<br />vegetation 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...

ver descrição completa

Detalhes bibliográficos
Autores: Marchesini, Victoria Angela, Fernandez, Roberto Julio, Jobbagy Gampel, Esteban Gabriel
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/4229
Acesso em linha:http://hdl.handle.net/11336/4229
Access Level:acceso abierto
Palavra-chave:Deforestation
Water Dynamics
Salt Dynamics
Semiarid Woodlands
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descrição
Resumo:Disturbances in semiarid environments have revealed a strong connection between water, salt and<br />vegetation 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 environmental<br />changes 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. A large 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. Under disturbed 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 the presence (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.