Effects of ponderosa pine afforestation on soil organic matter dynamics in semiarid rangeland steppes of western Patagonia, Argentina.

BUDUBA, C. G., G. E. DEFOSSÉ ; J. IRISARRI

AGROFORESTRY SYSTEMS

SPRINGER

Lugar: Berlin; Año: 2016

0167-4366

The western steppe of Patagonia, Argentina, is being afforested with conifers since long ago. However, the effects of this land-use change on some  soil parameters are still unknown. We determined soil organic matter (SOM) and root abundance at differentsoil depths, in 29 paired steppe-ponderosa pine (Pinus ponderosa Dougl. ex Laws.) stands planted at different times and densities between the 36430 and 4480S, and the 71290 and 70350W, in Patagonia, Argentina. SOM was significantly higher (p.05) in steppethan in afforestations at upper soil horizons (0?30 cm soil depth), and similar at deeper depths. Soil OM was also higher in steppe as compared to sparse/youngafforestation stands. Denser/older stands showed equal or slightly higher SOM values as compared to steppe. While root abundance was higher (p.05) in afforestations than in steppe at all but in the superficial soil horizon, it has not yet significantly contributed toSOM formation. This study contributes to the understanding of how ponderosa pine afforestations, planted on a steppe of Patagonia, affect SOM, adding useful information for other areas of the world in which afforestations replace native vegetation.