Análisis de la variabilidad espacial en el desarrollo del suelo y su relación con el almacenamiento de carbono en una microcuenca en el sur del Ecuador: Interacción de la cobertura vegetal y topografía

Abstract

The aim of this research was to analyze the influence of vegetation and topography on the storage of organic carbon and the thickness of the soil in a micro-basin of páramo in the south of Ecuador.A total of 135 sampling sites were selected, which were distributed within the study area. The sites were classified based on the vegetation cover (cushion plants, tussock grasses and native forest) and the topographic position (concave, convex and straight). Altered and unaltered soil samples were collected from the horizons (O, A, AC and AC) at each site. The organic carbon concentration (%C) and bulk density (DA) were determined for the collected soil samples in order to calculate the total carbon storage (TCS). Results showed average TCS values of 27.43 kg/m2 , 34.27 kg/m2 , 41.05 kg/m2 , for tussock grasses, cushion plants and forest vegetation respectively; while for the topographic position the average values varied from 31.06 kg/m2 , 35.16 kg/m2 and 36.53 kg/m2 , for concave, convex and straight, respectively. Forest soils have the greatest accumulation of organic carbon, followed by soils formed under cushion plants and tussok grass covers; although the latter two represent the most important soils for carbon reserves due to their extension on the territory. Furthermore, results revealed that the vegetation cover exerts a greater influence on the soil depth (soil thickness) compared to the effect of topography, especially at the valley bottoms and plain areas covered by cushions plants. Finally, this study has highlighted the importance of carbon storage in the subsoil as an important carbon source and it should be integrated in future research for modelling purposes.