IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Soil carbon dynamic associated to land-use changes in semi-arid forest of Argentina
Autor/es:
CONTI GEORGINA; KOWALJOW ESTEBAN; BAPTIST FLORENCE; RUMPEL CORNELIA; CUCHIETTI ANIBAL; DIAZ SANDRA
Lugar:
Cusco
Reunión:
Congreso; XX Latin American and XVI Peruvian Congress of Soil Science; 2014
Institución organizadora:
Sociedad Peruana de la Ciencia del Suelo
Resumen:
Land-use change
represents one of the main drivers of global climatic change, affecting the
amount and quality of organic matter (OM) in soils worldwide. A reduction in
the amount of biomass due to forest management is expected to affect both the
amount of new OM going into the soil and its microbial decomposability due to
changes in soil environmental conditions. These changes should impact soil
microbial communities, their activity and decomposition rates, affecting the
amount and quality of organic carbon (OC) remaining in the soil. In order to obtain information on the effect of land-use change on the
OM quantity and quality, its origin and its degree of stabilization (i.e.,
microbial decomposability), we characterized the amount of OC, the lignin and
polysaccharide compounds by wet chemical analysis, as well as basal respiration
rates across a disturbance gradient (n=20) in a semiarid Chaco forest of
central Argentina. Disturbance reduced the amount and quality of litterfall,
reflected in a reduction in SOM content. Soil carbohydrates content followed
the same trend but lignin was not affected by land-use change. Although basal
CO2 effluxes showed the same pattern than SOM content, when
normalized per OC content, they showed the opposite trend, with higher CO2
released per C in sites with lower OC and carbohydrates content. Our results
support the idea that in the semi-arid Chaco forest, chemically
labile compounds are more vulnerable to disturbance, but also that OM could be protected and stabilized regardless of its chemical
identity.