Production and utilization of dissolved organic carbon in riverine ecosystems. Meyer, J. Pages 281-300 in E, 1990.
abstract   bibtex   
Major sources of dissolved organic carbon (DOC) in streams and rivers are found within riparian zones and stream channels. In addition to DOC excreted by primary producers in the channel, DOC is rapidly leached from terrestrial leaves falling into streams. A more important DOC source appears to be DOC leached from material stored in the streambed. Leaching of this material is facilitated by biological activity and, in some cases, may occur under anaerobic conditions. The amount of DOC produced by these kinds of sources has been reduced by human activities that reduce channel storage and decouple rivers and floodplains. DOC is removed from the water column of lotic ecosystems by biotic and abiotic processes at rates ranging from \textgreater10-550 mg C m-2h-1. Abiotic removal processes include sorption, photooxidation, and particle formation. Biotic utilization of DOC is largely bacterial and varies with the chemical nature of DOC and the bacterial community. Epilithic microbial communities are important sites for DOC uptake in many streams. The extent of contact between water and sediments is a critical determinant of rates of DOC utilization in rivers. Consequences of DOC utilization include alteration of biogeochemical cycling of other elements an increase secondary production in the ecosystem. Three areas for future research are highlighted: (a) ecologically relevant chemical analyses of natural DOC that can be used routinely to characterize biological availability of DOC in aquatic ecosystems; (b) information on the rates and biotic availability of products of very slow leaching of stored organic matter; (c) hydrologic studies including work on water flow paths and residence times in the watershed to clarify DOC sources and work on water movement in streambed sediments to quantify exchanges of DOC between the sediments and water column.
@article{meyer_production_1990,
	title = {Production and utilization of dissolved organic carbon in riverine ecosystems.},
	abstract = {Major sources of dissolved organic carbon (DOC) in streams and rivers are found within riparian zones and stream channels. In addition to DOC excreted by primary producers in the channel, DOC is rapidly leached from terrestrial leaves falling into streams.  A more important DOC source appears to be DOC leached from material stored in the streambed. Leaching of this material is facilitated by biological activity and, in some cases, may occur under anaerobic conditions.  The amount of DOC produced by these kinds of sources has been reduced by human activities that reduce channel storage and decouple rivers and floodplains.  DOC is removed from the water column of lotic ecosystems by biotic and abiotic processes at rates ranging from {\textgreater}10-550 mg C m-2h-1.  Abiotic removal processes include sorption, photooxidation, and particle formation. Biotic utilization of DOC is largely bacterial and varies with the chemical nature of DOC and the bacterial community.  Epilithic microbial communities are important sites for DOC uptake in many streams.  The extent of contact between water and sediments is a critical determinant of rates of DOC utilization in rivers. Consequences of DOC utilization include alteration of biogeochemical cycling of other elements an increase secondary production in the ecosystem.  Three areas for future research are highlighted:  (a) ecologically relevant chemical analyses of natural DOC that can be used routinely to characterize biological availability of DOC in aquatic ecosystems; (b) information on the rates and biotic availability of products of very slow leaching of stored organic matter; (c) hydrologic studies including work on water flow paths and residence times in the watershed to clarify DOC sources and work on water movement in streambed sediments to quantify exchanges of DOC between the sediments and water column.},
	journal = {Pages 281-300 in E},
	author = {Meyer, J.L.},
	year = {1990},
	keywords = {CWT}
}
Downloads: 0