Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Argentine → Relaciones suelo-planta en el ecosistema Salinas Grandes, Provincia de Catamarca (Argentina)

Universidad Nacional de Córdoba (2013)

Relaciones suelo-planta en el ecosistema Salinas Grandes, Provincia de Catamarca (Argentina)

Karlin, Marcos Sebastián

Titre : Relaciones suelo-planta en el ecosistema Salinas Grandes, Provincia de Catamarca (Argentina)

Auteur : Karlin, Marcos Sebastián

Université de soutenance : Universidad Nacional de Córdoba

Grade : Doctor en Ciencias Agropecuarias 2013

Saline systems are open systems where energy and matter fluxes produce modifications in plant communities. Based on these changes, it is possible to define vectors that show the tendencies of such communities to reach mature or disturbed states. Relations among ecological variables were defined in order to understand the behavior of Salinas Grandes system. Soil and vegetation were sampled identifying five homogeneous zones. Phenological data was taken in each zone, along two successive seasons through visual observations of plant populations in different points of the basin. Lyapunov coefficients (L) were calculated as the Euclidean distance of each site from a reference condition, representing the exergy of the system. Edaphic and microtopographic characteristics define the physiognomy of each site with different offer of foraging plants. These sites can be clustered into management units, enabling the application of management patterns in each one of these. The decrease of electrical conductivity and pH, and the increase of sandy topsoil thickness, affect communities, increasing plant cover, biodiversity, minimum rangeland requirement and resilience. Results show signifficative differences in the periods of flowering and fructifying depending on the zone. Rains produce different phenological responses according to the evaluated families and in relation to the different considered zones. The changes of abundance and cover of key species are good indicators of edaphic changes, enabling to establish limits between zones. Electrical conductivity, biodiversity and cover could be used as indicators for minimum rangeland requirement. L is intimately related to soil salinity, and can be also used for the determination of minimum rangeland requirements. When L decreases in time, it is expected that the system goes towards a steady state. If the contrary occurs, the equilibrium is unstable and becomes less resilient. While primary succession evolves, minimum rangeland requirements increase. Anthropic degradation can produce retrogression of primary or secondary successions, through erosive processes and salinization.


Version intégrale (20,62 Mb)

Page publiée le 27 août 2016, mise à jour le 3 juillet 2017