Biophysical evaluation of fertility islands in the Arid Chaco (Argentina)

Abstract

Forests degradation in arid and semi-arid lands may conduct to the formation of “fertility islands” due to the accumulation of soil particles, water, nutrients and biomass under trees and shrubs. In the Arid Chaco fertility islands are characterised by the presence of Prosopis flexuosa and Larrea divaricata. The objective was to evaluate biophysical variables in soil, microclimate and the plant response under canopy and in intercanopy. Infiltrability, microtopography, soil bulk density, soil and air moisture and temperature, and light were measured under the canopy, at the limit of the canopy and in the intercanopy. These variables were correlated with the litter and plant frequencies associated with the fertility islands. P. flexuosa canopy and litter understorey tend to maintain more soil moisture compared with the intercanopy, by reducing soil and air temperature and by increasing air moisture. This increases the frequency of Dyksterhuis’ decreaser species. Under L. divaricata the canopy effect is not as effective as that of P. flexuosa and understorey plant response is not significative.

South American Dry Chaco rangelands: Positive effects of cattle trampling and transit on ecohydrological functioning

“…Cattle ranching in the Dry Chaco rangelands have a large effect on surface water redistribution at two different scales. On the one hand, cattle trample favors runoff/runon processes at the patch scale (<10 m 2 ) enhancing water concentration under vegetated patches (Karlin et al, 2021; Magliano, Breshears, et al, 2015; Magliano, Fernández, et al, 2015; Magliano, Murray, et al, 2015). As in other rangelands of the world, water redistribution among bare soil and vegetated patches increases plant transpiration (i.e., primary production) (Ludwig et al, 2005; Puigdefabregas et al, 1999; Urgeghe et al, 2010).…”

¿El bicho se caza o es de casa?: dicotomía entre el consumo y mascotismo de fauna silvestre en el Chaco Seco de la Provincia de Córdoba

“…Entre las estrategias productivas de los pobladores encontramos el desarrollo de economías domésticas y la venta de trabajo como asalariados temporales para conseguir un conveniente nivel de ingresos con el fin de cubrir las necesidades básicas del núcleo familiar. El trabajo predial se cubre con mano de obra familiar no remunerada (Coirini et al, 2010;Karlin et al, 1994), que consiste en la cría del ganado y aves de corral, y el aprovechamiento monetario y comercial de sus productos (Por ejemplo: huevos, cueros, gallinas, cabritos y terneros).…”