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Main Authors: Schefuß, Enno, Eglinton, Timothy Ian, Spencer-Jones, Charlotte L, Rullkötter, Jürgen, De Pol-Holz, Ricardo, Talbot, Helen M, Grootes, Pieter Meiert, Schneider, Ralph R
Format: Dataset Open Access
Language:en
Published: PANGAEA 2016
Subjects:
Online Access:https://doi.org/10.1594/PANGAEA.862021
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author Schefuß, Enno
Eglinton, Timothy Ian
Spencer-Jones, Charlotte L
Rullkötter, Jürgen
De Pol-Holz, Ricardo
Talbot, Helen M
Grootes, Pieter Meiert
Schneider, Ralph R
author_facet Schefuß, Enno
Eglinton, Timothy Ian
Spencer-Jones, Charlotte L
Rullkötter, Jürgen
De Pol-Holz, Ricardo
Talbot, Helen M
Grootes, Pieter Meiert
Schneider, Ralph R
collection Datos científicos de ciencias marinas y ambientales
contents The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments, it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and high carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River in conjunction with molecular markers for methane-producing land cover reflecting wetland extent in the watershed. We find that the Congo River has been discharging aged organic matter for several thousand years with increasing ages from the mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter we infer that this process may cause a profound direct climate feedback currently underestimated in carbon cycle assessments.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_862021
institution PANGAEA
language en
publishDate 2016
publisher PANGAEA
record_format pangaea
spellingShingle Geochemical data and radiocarbon ages of organic matter fractions and bacteriohopanepolyol data of sediment core GeoB6518-1 from the Congo River basin
Schefuß, Enno
Eglinton, Timothy Ian
Spencer-Jones, Charlotte L
Rullkötter, Jürgen
De Pol-Holz, Ricardo
Talbot, Helen M
Grootes, Pieter Meiert
Schneider, Ralph R
Center for Marine Environmental Sciences; MARUM
The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments, it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and high carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River in conjunction with molecular markers for methane-producing land cover reflecting wetland extent in the watershed. We find that the Congo River has been discharging aged organic matter for several thousand years with increasing ages from the mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter we infer that this process may cause a profound direct climate feedback currently underestimated in carbon cycle assessments.
title Geochemical data and radiocarbon ages of organic matter fractions and bacteriohopanepolyol data of sediment core GeoB6518-1 from the Congo River basin
topic Center for Marine Environmental Sciences; MARUM
url https://doi.org/10.1594/PANGAEA.862021