Infiltration rate and base infiltration in two shrub communities of the hyper arid desert of San Juan (Argentina)

Abstract

In arid and semi-arid regions, water represents the main limiting factor for net primary productivity and, consequently, determines the functioning of the ecosystem. The fraction of precipitation that enters the soil and remains available to plants depends on the interaction between precipitation, vegetation and soil. The shrub communities of arid zones are of great importance not only for their ability to maintain the physical structure of the landscape, but also for their contribution to the hydric dynamics of the ecosystem. The objective of the work was to evaluate the infiltration rate and base infiltration in two shrub communities of the hyper-arid desert of San Juan, Argentina. The shrub communities present in the study area were identified and characterized with remote sensing techniques and field work. Infiltration rate and basic infiltration measurements were made by the simple ring method. With the values obtained, the infiltration curves were constructed for the shrubby plant communities and also for soil free of vegetation. Two bush communities, Lamaral and Zampal, were recognized. Regarding infiltration, it was found that the mean infiltration speed was 1.98 times higher in the shrubs compared to bare soil. For basic infiltration, no statistically significant differences were found between the communities, but there were differences between them and the bare soil. The results reported here can be used as inputs for the elaboration or adjustment of hydrological models and for the management of the San Juan scrubs.