DOC Transport and Export in a Dynamic Tropical Catchment
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| Autores: | , , , , , , , , , , , , , , , , , , |
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| Formato: | artículo |
| Fecha de Publicación: | 2019 |
| Descripción: | Abstract Dissolved organic carbon (DOC) transport and export from headwater forests into freshwaters in highly dynamic tropical catchments are still understudied. Here we present a DOC analysis (2017) in a pristine and small (~2.6 km2) tropical catchment of Costa Rica. Storm flows governed a rapid surface and lateral allochthonous DOC transport (62.2% of the annual DOC export). Cross‐correlation analysis of rainfall and stream discharge indicated that DOC transport occurred on average ~1.25 hr after the rainfall maxima, with large contributions of event water, ranging from 42.4±0.3% up to 98.2±0.3% of the total discharge. Carbon export flux (annual mean=6.7±0.1 g C · m‐2 · year‐1) was greater than values reported in subtropical and temperate catchments. Specific ultraviolet absorbance indicated a mixture of hydrophobic humic and hydrophilic nonhumic matter during both baseflow and storm events. Our results highlight the rapid storm‐driven DOC transport and export as well as low biogeochemical attenuation during baseflow episodes in a climate sensitive hot spot. By understanding the key factors controlling the amount of organic carbon transported to streams in dynamic tropical landscapes, better global‐ and catchment‐scale model assessments, conservation practices, and water treatment innovations can be identified. Plain Language Summary Humid tropical forests represent ~20% of the global soil organic matter reservoirs. Nutrient availability coupled with transport and export of dissolved organic carbon (DOC) from forests into freshwater ecosystems is still poorly understood in the tropics. Here we present a study of DOC dynamics in a humid tropical catchment of central Costa Rica. Overall, DOC was transported from the forest to the stream on average within ~1.25 hr after large rainfall events. Storm flows were dominated by event water (recent rainfall) in the catchment. Fluvial carbon flux exported from the catchment was estimated at 6.7±0.1 g C · m‐2 · year‐1. Our results highlight the rapid DOC transport and export during storm flows as well as low biodegradation during baseflow episodes. These findings may contribute to improve model calibration and validation considering the limited high‐resolution DOC data in dynamic tropical landscapes. |
| País: | Repositorio UNA |
| Institución: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Lenguaje: | Español |
| OAI Identifier: | oai:null:11056/20841 |
| Acceso en línea: | http://hdl.handle.net/11056/20841 |
| Palabra clave: | AGUA DULCE TRATAMIENTO DE RESIDUOS ECOSISTEMAS BOSQUES CARBONO DISSOLVED ORGANIC CARBON (DOC) LLUVIA RAIN ECOSYSTEMS |