Abstract

SCHMIDT, Erica Susana; BOLLO, Domingo Federico  and  GARAY, Maximiliano. Eucalyptus viminalis L. In ventania: effects on some surface soil properties. Cienc. suelo [online]. 2019, vol.37, n.1, pp.91-100. ISSN 1850-2067.

The implementation of forest species in environments without trees contributes to the mitigation of global climate change, because it is an effective method of capturing CO₂. However, it can also have a negative environmental impact generating a loss of soil quality. The objectives of this work were: i) to evaluate some physical and chemical properties of the superficial mineral horizons of the soils (0-20 cm) of the Ventania area under forest stands of Eucalyptus viminalis L. (EV) and natural gramineous vegetation (situation of reference, PN), and ii) determine whether variations in soil properties within the stands are associated with the circular influence of the individual trees. Under EV we observed values of 30.0 g kg^-1 and 12.1 g kg^-1 of total organic carbon (COT) and organic carbon bound to the coarse fraction (COPg), while in PN they were 12.0 g kg^-1 and 3.6 g kg^-1, respectively. On the other hand, in relation to the values obtained for PN, under the trees there was a significant decrease in pH (5.8 vs 6.4) and increases in extractable phosphorus (Pe) (37.7 vs 2.7 mg kg^-1). No effects of afforestation were detected on the structural stability of the soil. In addition, in this research it was observed that the individual trees within the forest stands give rise to a spatial variability of the properties of the superficial surface of the soil, with a progressive and significant increase in the contents of COT and Pe from the 2 m towards the axis of the trees, and decreases in pH and in the COT/COPg ratios in the same direction. In the region, afforestation with eucalyptus had a positive impact on the sequestration of C in the soils in the medium-long term. However, the alterations of the pH observed in the superficial horizons indicate the need to continue with the monitoring of the negative effects of its implantation on the soil resource.

Keywords : Changes in land use; pH; soil organic matter; structural stability.