Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia

Flooded savannas are extensive in South America and this study was conducted to assess two digital soil mapping (DSM) approaches to predict the spatial distribution of soil organic carbon (SOC) content and stocks in the Orinoco flooded savannas of Casanare department, located in the eastern plains o...

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Autores principales: Martin López, Javier Mauricio, Verchot, Louis V., Martius, Christopher, Silva, Mayesse Aparecida da
Formato: Ponencia
Lenguaje:Inglés
Publicado: Copernicus GmbH 2022
Materias:
Acceso en línea:https://hdl.handle.net/10568/119694
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author Martin López, Javier Mauricio
Verchot, Louis V.
Martius, Christopher
Silva, Mayesse Aparecida da
author_browse Martin López, Javier Mauricio
Martius, Christopher
Silva, Mayesse Aparecida da
Verchot, Louis V.
author_facet Martin López, Javier Mauricio
Verchot, Louis V.
Martius, Christopher
Silva, Mayesse Aparecida da
author_sort Martin López, Javier Mauricio
collection Repository of Agricultural Research Outputs (CGSpace)
description Flooded savannas are extensive in South America and this study was conducted to assess two digital soil mapping (DSM) approaches to predict the spatial distribution of soil organic carbon (SOC) content and stocks in the Orinoco flooded savannas of Casanare department, located in the eastern plains of Colombia. SOC was estimated using a total of 80 sites sampled at two soil depth intervals (0-10 cm and 10-30 cm). SOC ranged from 0.41% at 0-10 cm and 0.23% at 10-30 cm in drier soils found in continental dunes with sandy textures and low vegetation cover (steppe) to over 14.50% and 7.51% in soils that experienced seasonal flooding located in depressions with loamy textures and flooded savanna vegetation. Predictions of the spatial distribution of SOC were done through Expert Knowledge (EK) and Random Forest (RF) approaches across the study area at 0-10 cm and 10-30 cm soil depth. Both DSM approaches were assessed through root mean square errors, mean absolute errors, and coefficients of determination. Although both DSM approaches performed very well, EK was considered slightly superior to predict SOC in the Casanare flooded savannas. Covariates derived from vegetation coverage, topography, and soil texture properties were identified as key drivers in controlling its distribution at the study area. We found total SOC stocks of 55.07 Mt with a mean density of 83.13 ± 24.32 t ha-1 stored in the first 30 cm soil depth, with 12.3% of this being located in the flooded parts of the savanna landscape, which represented only 7.9% of the study area (664,752 ha). This study provides the first effort to systematically quantify SOC stocks in the Casanare flooded savannas and shows the importance of conserving this ecosystem with the aim of avoiding SOC losses and consequent increased CO2 emissions to the atmosphere. We estimate that the department of Casanare would release an average of 2,42 Mton of CO2 emissions per year over 30 years if there were large scale conversion of the flooded savannas to intensive agriculture, which corresponds to 62% of the current emissions of the department. At regional level, the impact of a large-scale land use conversion of the flooded Llanos del Orinoco ecosystem area (15 Mha) would represent 1/3 of the current net Colombian CO2 emission (AFOLU), which makes this region a potentially important source of emissions if correct decisions are not taken regarding the land management.
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spelling CGSpace1196942025-11-12T05:32:18Z Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia Martin López, Javier Mauricio Verchot, Louis V. Martius, Christopher Silva, Mayesse Aparecida da spatial distribution soil organic carbon atmospheric co2 distribución espacial carbono orgánico del suelo co2 atmosférico Flooded savannas are extensive in South America and this study was conducted to assess two digital soil mapping (DSM) approaches to predict the spatial distribution of soil organic carbon (SOC) content and stocks in the Orinoco flooded savannas of Casanare department, located in the eastern plains of Colombia. SOC was estimated using a total of 80 sites sampled at two soil depth intervals (0-10 cm and 10-30 cm). SOC ranged from 0.41% at 0-10 cm and 0.23% at 10-30 cm in drier soils found in continental dunes with sandy textures and low vegetation cover (steppe) to over 14.50% and 7.51% in soils that experienced seasonal flooding located in depressions with loamy textures and flooded savanna vegetation. Predictions of the spatial distribution of SOC were done through Expert Knowledge (EK) and Random Forest (RF) approaches across the study area at 0-10 cm and 10-30 cm soil depth. Both DSM approaches were assessed through root mean square errors, mean absolute errors, and coefficients of determination. Although both DSM approaches performed very well, EK was considered slightly superior to predict SOC in the Casanare flooded savannas. Covariates derived from vegetation coverage, topography, and soil texture properties were identified as key drivers in controlling its distribution at the study area. We found total SOC stocks of 55.07 Mt with a mean density of 83.13 ± 24.32 t ha-1 stored in the first 30 cm soil depth, with 12.3% of this being located in the flooded parts of the savanna landscape, which represented only 7.9% of the study area (664,752 ha). This study provides the first effort to systematically quantify SOC stocks in the Casanare flooded savannas and shows the importance of conserving this ecosystem with the aim of avoiding SOC losses and consequent increased CO2 emissions to the atmosphere. We estimate that the department of Casanare would release an average of 2,42 Mton of CO2 emissions per year over 30 years if there were large scale conversion of the flooded savannas to intensive agriculture, which corresponds to 62% of the current emissions of the department. At regional level, the impact of a large-scale land use conversion of the flooded Llanos del Orinoco ecosystem area (15 Mha) would represent 1/3 of the current net Colombian CO2 emission (AFOLU), which makes this region a potentially important source of emissions if correct decisions are not taken regarding the land management. 2022-05-24 2022-05-31T07:34:47Z 2022-05-31T07:34:47Z Presentation https://hdl.handle.net/10568/119694 en Limited Access application/pdf Copernicus GmbH Martín-López, J.M.; Verchot, L.; Martius, C.; da Silva, M. (2022) Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia.[Presentation] EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1840
spellingShingle spatial distribution
soil organic carbon
atmospheric co2
distribución espacial
carbono orgánico del suelo
co2 atmosférico
Martin López, Javier Mauricio
Verchot, Louis V.
Martius, Christopher
Silva, Mayesse Aparecida da
Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title_full Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title_fullStr Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title_full_unstemmed Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title_short Modeling the spatial distribution of soil organic carbon and carbon stocks for the Casanare flooded Savannas, Colombia
title_sort modeling the spatial distribution of soil organic carbon and carbon stocks for the casanare flooded savannas colombia
topic spatial distribution
soil organic carbon
atmospheric co2
distribución espacial
carbono orgánico del suelo
co2 atmosférico
url https://hdl.handle.net/10568/119694
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