The challenge of restoring salinized environments in irrigated arid lands of Western Argentina: Salt tolerance thresholds in Prosopis species

ALVAREZ, JUAN AGUSTÍN; CONY, MARIANO ANIBAL; MEGLIOLI, PABLO ANDRÉS; VILLAGRA, PABLO EUGENIO; LANA, BELÉN NERINA

Cape Town South Africa

Conferencia; 8th World Conference on Ecological Restoration; 2019

Society for Ecological Restoration

The irrigated oases of the arid lands of western Argentina present large areas with low suitability for traditional crops due to soil salinization caused by inappropriate irrigation practices and the ascent of the phreatic level. Forestation with the native trees Prosopis flexuosa and P. chilensis has emerged as an alternative to the environmental and productive recovery of these areas. These species could be useful owing to their stress resistance and multiple uses (posts, firewood, and hardwood) and environmental benefits they provide. In order to select suitable genetic material for restoration, we assessed the salinity tolerance of P. flexuosa and P. chilensis from three different origins by conducting field experiments on typical agrosystems at Media Agua, San Juan, Argentina (31°52´ S - 68°23´ W). Sixteen plots were experimentally forested (2 species x 3 origins x 20 plants) in a salinity gradient on the irrigated oasis. At each plot, we measured plant survival and growth annually. Additionally, we analyzed the spatial heterogeneity of soil salinity within each plot and we correlated it with spatial variability in survival and growth. We observed a significant and negative correlation between soil electrical conductivity and biological variables. Survival was higher than 50% up to 40,000 μS/cm. Differential growth and mortality within the plot was observed as a response to heterogeneity in soil salinity. Our data suggest tolerance of both species up to high salinity levels. This tolerance was relatively independent of the origin, the differences in growth observed among origins growing in optimal conditions were maintained.