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Las emisiones de gases de los ríos y humedales amazónicos son una gran fuente tropical de CO2 atmosférico
Jeffrey E Richey1, John M Melack, Anthony K Aufdenkampe
1School of Oceanography, University of Washington, Seattle, Washington 98195, USA. jrichey@u.washington.edu
Nature
|April 12, 2002
Resumen
Las selvas tropicales lluviosas tropicales.
Área de la Ciencia:
- Ciencias ambientales Ciencias ambientales.
- Ecología Ecología Ecología.
- Biogeoquímica La biogeoquímica es la bioquímica.
Sus antecedentes:
- El papel de los ecosistemas tropicales en el ciclo global del carbono es incierto.
- Las estimaciones varían dependiendo de si los bosques tropicales son sumideros o fuentes de carbono.
- Estudios anteriores se centraron principalmente en el intercambio de carbono terrestre.
Objetivo del estudio:
- Para cuantificar el dióxido de carbono (CO2) emitido por los ríos y humedales amazónicos.
- Evaluar la importancia de la pérdida de carbono acuático en el presupuesto de carbono de la cuenca del Amazonas.
- Reevaluar el balance neto de carbono de las selvas tropicales, incluidos los sistemas acuáticos.
Principales métodos:
- Medición de la desgasificación (evasión) de CO2 de ríos y humedales en el Amazonas central.
- Flujo de carbono estimado a partir de las mediciones del intercambio de gases.
- Extrapolación del flujo en toda la cuenca basado en mediciones localizadas.
Principales resultados:
- La desgasificación de CO2 de los ríos y humedales amazónicos es un proceso de pérdida significativa de carbono (1.2 ± 0.3 Mg C ha-1 yr-1).
- Este flujo de CO2 acuático, estimado en 0,5 Gt C yr-1, es sustancial en comparación con las exportaciones fluviales.
- El carbono probablemente se origina en la materia orgánica terrestre respirada en los sistemas acuáticos.
Conclusiones:
- La desgasificación acuática de CO2 es una de las principales vías de pérdida de carbono en la Amazonía, anteriormente subestimada.
- La inclusión de entornos acuáticos sugiere que las selvas tropicales están más cerca del equilibrio de carbono.
- Este estudio pone de relieve la importancia de los estudios terrestres y acuáticos integrados para la evaluación del ciclo del carbono.
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