Fine root biomass and its relationship with the soil in degraded areas by mining in biogeographic Chocó

Abstract

Fine root biomass (FRB) is essential for the functioning of tropical forests. However, due to the degradation generated by mining, it is necessary to evaluate the influence of the soil and the successional time on the FRB, to contribute to its restoration. Forests of biogeographic Chocó have been affected by mining; for this reason, the objective of evaluating the influence of the soil and the successional time on the FRB in abandoned mines was proposed. For this, plots were established in three successional stages: two abandoned mines (12-15 and 30-35 years) and a primary forest. Subsequently, the physicochemical conditions of the soil and the FRB (<2 mm) at 20 cm depth were measured. The registered FRB was 5.73 t ha-1 in stages of 12-15 years, 2.56 t ha-1 in stages of 30- 35 years, and 5.91 t ha-1 forests; that is, it recovered quickly, but did not increase with successional time. In general, the FRB was determined by successional age, fertility, OM, and clay. In stages of 12-15 years, it was positively associated with OM and slime; and negatively with clay and sand. While, in stages of 30-35 years, it was positively related to Al, N, Ca and clay; but, with K, MO and Mg it was negative. In summary, it was determined that the soils have a different influence on the FRB in each successional stag. In addition, the limitation of belowground biomass storage due to multiple nutrients, which affect the mitigation of global climate change, was noted.