Estimation of organic carbon in paramo ecosystem soils in Colombia

Abstract

Gutiérrez, J., Ordoñez, N., Bolívar, A., Bunning, S., Guevara, M., Medina, E., Olivera, C., Olmendo, G., Rodríguez, L., Sevilla, V., Vargas, R. 2020. Estimation of organic carbon in paramo ecosystem soils in Colombia. Ecosistemas 29(1):1855. https://doi.org/10.7818/ECOS.1855

The mountainous ecosystems (in which the paramos are found) occupy a fifth of the earth’s surface, hold 25% of the planet’s biodiversity and supply water to almost half of the world’s population. They are considered strategic for climate change due to their relationship with carbon dioxide capture and storage. With the objective of estimating the organic carbon content in the first 30 cm of depth in the soils (COS) of Colombia páramos, and its relationship with the environmental factors affecting its spatial patterns, by means of digital soil mapping; 390 profiles were taken from the semi-detailed studies of soils in an area of ​​1 469 980.1 ha (approximately 1.3% of the national area). The missing information of bulk density was estimated by means of pedotransference functions adjusted with the available data. The predictive modeling technique was Random Forest (RF), using 44 environmental covariables as possible predictors that included information on climate, vegetation, relief and soil orders. The quality of the model was evaluated by cross validation (R2 = 0.48 – 0.52). The estimated COS content oscillated between 22 and 338 t.ha-1, this is related to the coverage and use of the soil and the climatic conditions (temperature and precipitation). The map of COS of páramos of Colombia establishes a baseline of this indicator for the ecosystem, provides an overview of the susceptibility to soil degradation and serves as support for the planning of the territory.