Global effects of agriculture on fluvial dissolved organic matter
Global effects of agriculture on fluvial dissolved organic matter
Authors
Graeber, Daniel
Boechat, Iola G.
Encina Montoya, Francisco
Esse, Carlos
Gelbrecht, Joerg
Goyenola, Guillermo
Guecker, Bjoern
Heinz, Marlen
Kronvang, Brian
Meerhoff, Mariana
Nimptsch, Jorge
Pusch, Martin T.
Silva, Ricky C. S.
von Schiller, Daniel
Zwirnmann, Elke
Boechat, Iola G.
Encina Montoya, Francisco
Esse, Carlos
Gelbrecht, Joerg
Goyenola, Guillermo
Guecker, Bjoern
Heinz, Marlen
Kronvang, Brian
Meerhoff, Mariana
Nimptsch, Jorge
Pusch, Martin T.
Silva, Ricky C. S.
von Schiller, Daniel
Zwirnmann, Elke
Authors
Date
Datos de publicaciĆ³n:
SCIENTIFIC REPORTS,Vol.5,,2015
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Abstract
Agricultural land covers approximately 40% of Earth's land surface and affects hydromorphological, biogeochemical and ecological characteristics of fluvial networks. In the northern temperate region, agriculture also strongly affects the amount and molecular composition of dissolved organic matter (DOM), which constitutes the main vector of carbon transport from soils to fluvial networks and to the sea, and is involved in a large variety of biogeochemical processes. Here, we provide first evidence about the wider occurrence of agricultural impacts on the concentration and composition of fluvial DOM across climate zones of the northern and southern hemispheres. Both extensive and intensive farming altered fluvial DOM towards a more microbial and less plant-derived composition. Moreover, intensive farming significantly increased dissolved organic nitrogen (DON) concentrations. The DOM composition change and DON concentration increase differed among climate zones and could be related to the intensity of current and historical nitrogen fertilizer use. As a result of agriculture intensification, increased DON concentrations and a more microbial-like DOM composition likely will enhance the reactivity of catchment DOM emissions, thereby fuelling the biogeochemical processing in fluvial networks, and resulting in higher ecosystem productivity and CO2 outgassing.