Evaluación de la Reserva de Carbono en el Suelo del Humedal El Charco-Oasis En Villavicencio, Meta

Abstract

This study assessed the soil organic carbon storage capacity of El Charco–Oasis wetland, an urban ecosystem located in Villavicencio, Meta, Colombia, in order to quantify its contribution as a carbon sink. Seven sampling sites were established through a purposive sampling design that accounted for the environmental heterogeneity of the ecosystem. At each site, a 10 m linear transect was established, and soil subsamples were collected to a depth of 60 cm and combined into composite samples. Soil physicochemical properties, including texture, bulk density, pH, nutrient content, and organic matter, were determined through laboratory analyses. Total organic carbon was quantified using the Walkley–Black method, carbon stocks were estimated following the IPCC (2006) guidelines, and the factors associated with carbon distribution were evaluated through correlation analysis and Principal Component Analysis (PCA). Spatial distribution patterns were represented using Inverse Distance Weighting (IDW) interpolation. The results revealed soil organic carbon contents ranging from 0.46% to 1.38% (mean: 0.92%) and carbon stocks ranging from 41.79 to 124.70 t C ha⁻¹ (mean: 83.8 t C ha⁻¹). Correlation analysis indicated that organic carbon was primarily associated with total exchangeable bases, soil pH, and exchangeable aluminum, whereas the first two principal components explained 63.33% of the total variability. Spatial distribution exhibited a heterogeneous pattern, with higher carbon stocks concentrated in the central sector of the wetland and lower values recorded in peripheral areas. Based on the mean carbon stock, soil carbon storage was estimated at 341.74 t C for the effectively surveyed area (4.078 ha) and 537.57 t C for the total wetland area. These findings underscore the importance of El Charco–Oasis wetland as a strategic carbon reservoir within an urban landscape and highlight its contribution to local climate change mitigation efforts. Furthermore, the estimated carbon stock exceeds the institutional carbon footprint reported for 2020 (215.86 t CO₂) and 2023 (315.07 t CO₂), demonstrating its potential role in carbon offsetting. The ecosystem also contributes to the achievement of SDG 11 (Sustainable Cities and Communities), SDG 13 (Climate Action), and SDG 15 (Life on Land).