Soil water dynamics, root systems, and plant responses in a semiarid grassland of Southern Patagonia

Distribution of water enables different ecological niches and the coexistence of species. This separation may be in space: vertically in the soil profile or horizontally by lateral root exploration; and in time, as plants may use water at different periods. This study focused on the soil-plant water relation in semiarid Patagonia. Water potential at three depths: 10, 25 and 60cm, and water content beneath vegetated and bare batches were measured. Access to water in the soil profile was studied in two grasses and a dwarf shrub based on the root biomass. Soil was usually dry at 10cm [-1.22MPa plus or minus 0.25] and 25cm [-1.00MPa plus or minus 0.14] during summer. In dry years, it was also dry during autumn [-1.17MPa plus or minus 0.32] at 10cm depth]. At 60-cm depth, soil was moist year-round [-0.38MPa plus or minus 0.05]. Soil conditions were not spatially homogeneous, as bare soil patches showed higher water content than vegetated patches. Dwarf shrubs presented both shallow and long roots, that extended laterally instead of exploring deep soil. It is hypothesized that this lateral expansion may give access to water under the bare soil patches, a resource that is not available to the other life forms.

Bibliographic Details

Main Authors:	Ferrante, Daniela, Oliva, Gabriel Esteban, Fernández, Roberto Javier
Format:	Texto biblioteca
Language:	spa
Subjects:	COEXISTENCE, GRASSLAND, LEAF WATER POTENTIAL, NICHE, PATAGONIA, PLANT COMMUNITY, RAINFALL EVENT, RANGELAND HYDROLOGY, ROOT BIOMASS, ROOT SYSTEM, SEASONAL VARIATION, SEMIARID REGION, SOIL PROFILE, SOIL WATER, VEGETATION PATCHES, WATER USE EFFICIENCY,
Online Access:	http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=47018
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