Soil Physical Changes after Conversion of Woodlands to Pastures in Dry Chaco Rangelands (Argentina)

Authors
Magliano, Patricio Nicolás; Fernandez Alduncin, Roberto Javier; Florio, Eva Laura; Murray, Francisco; Jobbagy Gampel, Esteban Gabriel
Publication Year
2017
Language
English
Format
article
Status
Published version
Description
The conversion of dry woody rangelands into pastures can alter key soil physical properties that regulate ecosystem water circulation and storage. Based on three paired stands of native woodlands and pastures established 20 years ago in the southern Dry Chaco (San Luis, Argentina), we described contrasts in five soil physical properties using a systematic sampling of soil patches (9-18 patches along a single transect within each of the three paired 1-ha stands). Compared with woodlands, pastures displayed flatter microtopography (mean ± standard deviation [SD]: 3.7 ± 0.34 vs. 5.0 ± 0.67% slope; P < 0.05), lower infiltration rate (mean ± SD: 71.6 ± 9.0 vs. 139.9 ± 37.2 mm h-1; P < 0.05), and higher penetration resistance (mean ± SD: 4.2 ± 0.10 vs. 1.9 ± 0.17 kg cm-2; P < 0.01) and bulk density (mean ± SD: 1.39 ± 0.05 vs. 1.16 ± 0.04 g cm-3; P < 0.0001). On average, topsoil water content at field capacity was similar for both types of cover (mean ± SD: 16.3 ± 0.21 vs. 17.1 ± 1.12%, pastures and woodlands, respectively; P = 0.29). However, at similar bulk density values, pastures presented a ∼20% reduction in volumetric water content at field capacity (16.3%) compared with woodlands (19.7%). The establishment of pastures led to more homogenous soils, with most variables having reduced spatial variability in comparison with woodlands. Our observations showed how the conversion of native woodlands to pastures produced strong physical changes in the soils of Dry Chaco and help to understand the mechanisms that are most likely influencing the surface-soil water dynamics of these, and perhaps other, dry rangelands.
Fil: Magliano, Patricio Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina. Universidad Nacional de San Luis; Argentina
Fil: Fernandez Alduncin, Roberto Javier. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina
Fil: Florio, Eva Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina
Fil: Murray, Francisco. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina
Fil: Jobbagy Gampel, Esteban Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina. Universidad Nacional de San Luis; Argentina
Subject
ARID CHACO
DEFORESTATION
ECOHYDROLOGY
LAND USE/LAND COVER CHANGE
WATER BALANCE
Ciencias Medioambientales
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Oceanografía, Hidrología, Recursos Hídricos
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/66241