We have a long history of working on the biogeochemistry and hydrology of the Amazon River system. The RV Alpha Helix expeditions of 1977 (Richey at al. 1980, Wissmar 1980) led to the establishment of CAMREX (Carbon in the AMazon River Experiment). Starting in 1982 with NSF funding, we began a series of research cruises on the Amazon/Solimoes, sampling the mainstem, mouths of major tributaries, and varzea (floodplain). These cruises led to further projects with NSF , NASA (the ABLE and EOS Mission to Planet Earth), and FAPESP ( Brazilian-funded) experiments. More recently, we have been part of the NASA LBA (Large Scale Biosphere Atmosphere) program. Our overall perspective in CAMREX has been that the Amazon is a test case for developing extendable models of how hydrologic and biogeochemical cycles are coupled at regional to continental scales in the humid tropics. Our studies serve the dual purposes of gaining a broad mechanistic understanding and of establishing data baselines needed to assess anthropogenic perturbations to these globally critical and ecologically complex systems. As documented in over 150 publications, the CAMREX dataset represents a time series unique in its length and detail for very large river systems. The papers produced by this work are given under Publications.

A signature of CAMREX is that is has been a joint, collaborative effort of the UW and Brazilian institutions, in particular CENA (Centro de Energia Nuclear na Agricultura, Piracicaba SP) and INPA (Instituto Nacional de Pesquisas da Amazonia, Manaus).  As part of LBA, we established the education and sampling network the Rede Beija Rio (RBR), supported subsequently by the Brazilian government (FAPESP, CNPq). The RBR serves the dual purpose of enabling higher frequency (and less expensive) sampling than possible by sending teams from São Paulo or Seattle, and especially serves as our primary vehicle for training and capacity building. The sites are organized as transects, from the Amazon mainstem and major tributary mouths (the initial CAMREX scheme), to primary tributaries, then sub-tributaries, and ultimately streams The RBR is made up of nodes distributed across the Amazon, where each node is occupied by a researcher or a team of researchers from that site-typically a professor, graduate and/or undergraduate students from local institutions, working from a coordinated sampling plan. Over 40 Brazilian students have participated in the project since its beginning, earning Masters and PhDs. Most of these students have been from the Amazon, a region markedly under-represented in technical training in the country.   

 Recent work has focused on investigating effects of landuse change and on the processes involved in producing the outgassing reported by Richey et al. (2002). Papers published and in development  cover a series of topics, including modeling and system integration (Richey et al. 2004; Richey 2004, 2005), biogeochemistry within geospatial frameworks (Ballester et al. 2003, 2005; Bernardes et al. 2004; Mayorga et al. 2005a, Logsdon et al. 2005; Krusche et al. 2005), hydrologic models (Victoria et al. 2007; Santiago et al. in review), gas exchange (Rasera et al. 2008; Alin et al.   in revision), basin scale tracers of sorption and metabolic properties (Martinelli et al. 2003; Mayorga et al. 2005b; Aufdenkampe et al. 2007; Remington et al. 2007; Souza et al. 2008; Ellis et al. in review), and chemical properties (Dickens et al. 2007, Tumang et al. 2007). Richey et al. (in press) have summarized the current understanding of carbon in Amazon rivers.  



Alin, S.R., M.Fátima Rasera, C. I. Salimon, J.E. Richey, A.V. Krusche, G.W. Holtgrieve, and A. Snidvongs. (in revision). Environmental controls on carbon dioxide flux, transfer velocity, and partial pressure in the Amazon and Mekong river basins (Brazil, Southeast Asia). J. Geophysical Research.

Aufdenkampe, A.K.,  E. Mayorga, J.I. Hedges, C. Llerena, P.D. Quay, J. Gudeman, A.V. Krusche, J. E. Richey. 2007. Organic matter in the Peruvian headwaters of the Amazon: A comparison to Bolivian tributaries and the lowland Amazon mainstem. Organic Geochemistry 38: 337-364.

Ballester, M.V.R., D. Victoria, A.V. Krusche, R. Coburn, R.L. Victoria, J.E. Richey, , M.G. Logsdon, E. Mayorga, and E. Matricardi. 2003. Land use/cover of the Ji-Paraná river basin: building a GIS-based physical template to support the understanding of the biogeochemistry of surface waters in a meso-scale river in Western Amazônia. Remote Sensing of the Environment 87: 429-445.

Ballester, M.V.R. A.V. Krusche, R.L. Vistoria, A.A. Montebello, N.K. Leite,  D. Victoria, and J.E. Richey 2005. Uso de geoprocessamento em estudos de ecossistemas fluviais. In: F. Roland, D. Cesar, and M. Marinho (eds.) Lições de Limnologia.  Pp 433-460.

Bernardes, M. C., L.A. Martinelli, A.V. Krusche, J. Gudeman, M.Z.  Moreira, R.L. Victoria, J.P.  Ometto, M.V. Ballester, A.K. Aufdenkampe, J.E.  Richey, and J.I. Hedges. 2004. Riverine organic matter composition as a function of land use changes, Southwest Amazon. Ecological Applications 14: S263-S279.

Dickens, A.F., J.A. Gudeman, Y. Gélinasc, J.A. Baldock, W. Tinner, F. S. Hu and J.I. Hedges. 2007.  Sources and distribution of CuO-derived benzenecarboxylic acids in soils and sediments. Organic Geochemistry 38: 1256-1276.

Ellis, E.E., J.E. Richey, A.K. Aufdenkampe, P.D. Quay, A.V. Krusche, C. Salimon, and H.B. da Cunha. (in review). Factors controlling aquatic respiration and its role in fueling CO2 gas evasion in rivers of the central and southwestern Amazon Basin. Limnol. Oceangr.

Krusche, A.K.,  M.V. Ballester, R.L. Victoria, M.C. Bernardes, N. K. Lei, L. Hanada, D.Victoria, A. M. Toledo, J.P. Ometto, M.Z. Moreira, B.M. Gomes, M. A. Bolson, S.G. Neto, N. Bonelli, L. Deegan, C. Neill, S. Thomas, A. Aufdenkampe, and J.E. Richey. 2005. Effects of landuse changes in the biogeochemistry of fluvial systems of the Ji-Parana river basin, Rondonia. Acta Amazonica 35: 197-205.

Logsdon , M.G., R. Weeks, M. Smith, J.E. Richey, V. Ballester, and Y. Shimabukoro. 2005. Detection of mesoscale seasonal and inter-annual variation in vegetation of the Amazon Basin. Earth Interactions 9: 1:16.

Martinelli, L.A., R.L. Victoria, P.B. de Camargo, M.Piccolo, L. Mertes, J.E. Richey, A.H. Devol, B.R. Forsberg. 2003. Inland variability of carbon-nitrogen concentrations and 13C in Amazon floodplain (várzea) vegetation and sediment.  Hydrol. Processes.  1419-1430. DOI: 10.1002/hyp.1293

Mayorga, E., Logsdon, M. G., Ballester, M. V. R. & Richey, J. E. 2005. Estimating cell-to-cell land surface flow paths from digital channel networks, with an application to the Amazon basin. Journal of Hydrology 315: 167-182

Mayorga, E., A.K. Aufdenkampe, A. K., C.A. Masiello, A.V. Krusche, J.I. Hedges,  P.D.  Quay, P. D., J.E. Richey, and T.A. Brown. 2005. Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers. Nature 436: 538-541.

Rasera, M, M.V.R. Ballester, A.V. Krusche,C. Salimon, L.A. Montebelo, S.R. Alin, R.L. Victoria, and J.E. Richey. 2008. Estimating the surface area of small rivers in the southwestern Amazon and their role in CO2 outgassing. Earth Interactions. 12: 1-16.

Remington, S., B.D. Strahm, V. Neu; J.E. Richey, and H. Brandao. 2007. The role of sorption in control of riverine DOC concentrations by riparian zone soils in the Amazon basin. Soil Science 172: 279-291.

Richey, J. E., J. T. Brock, R. J. Naiman, R. C. Wissmar, and R. F. Stallard. 1980. Organic carbon: oxidation and transport in the Amazon River. Science, 207: 1348-1351.

Richey, J.E., J.M. Melack, A.K. Aufdenkampe, V.M. Ballester, and L. Hess. 2002. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2. Nature 416: 617-620.

Richey, J., R. Victoria, E. Mayorga, L. Martinelli, and R. Meade. 2004. Integrated Analysis in a Humid Tropical Region - The Amazon Basin. Pp.415-428. In P. Kabat  et al (eds) Vegetation, Water, Humans, and the Climate. Springer, Berlin.  566p.

Richey, J.E. 2004. Pathways of Atmospheric CO2 through Fluvial Systems. Pp. 329-340. In (C. Fields, ed.). Toward CO2 Stabilization: Issues, Strategies, and Consequences, A SCOPE/GCP Rapid Assessment Project. Island Press. 526p.

Richey, J.E. 2005. Global River Carbon Biogeochemistry.  (in. M. Anderson, Ed.) Encyclopedia of Hydrological Sciences Part 15. Global Hydrology. John Wiley & Sons, Ltd DOI:10.1002/0470848944.hsa191

Richey, J.E., A.V. Krusche, M.S. Johnson, H.B. da Cunha, and M.V. Ballester. (in press). The role of rivers in the regional carbon balance. in   M.  Keller, M. Bustamante, J. Gash, and P. Dias (eds.) LBA Synthesis Volume - Amazonia and Global Change.  American Geophysical Union Press.

Santiago, A.V., A.R. Pereira, D.C. Victoria, M.V.R. Ballester, and R.L. Victoria (in review). Simulations of the Effects of vegetation cover in the water balance of Ji-Paraná River Basin, Rondônia, Brazil. Acta Amazonica.

Souza, E., C. Salimon, R.L. Victoria, A. Krusche, S. Alin, and N.K. Leite. 2008. Dissolved inorganic carbon and pCO2 in two small streams draining different soil types in the Southwestern Amazonia, Brasil. Revista Ambiente e Agua, v. 3, p. 37-58.

Tumang, C. A., A.V. Krusche, R.L. Victoria, and J.E. Richey. 2007. On line pre-concentration for simultaneous determination of low molecular weight organic acids and inorganic anions in Amazonian river water samples employing in chromatography with conductivity detection. Acta Amazonica, v. 37, p. 287-294.

Victoria, D.C., A.V. Santiago, M.V. Ballester, A.R. Pereira, and J.E. Richey. 2007. Water balance for the Ji-Paraná river basin, western Amazon, using a simple method through Geographical Information Systems (GIS) and Remote Sensing. Earth Interactions 11: 1-22.

Wissmar, R. C., J. E. Richey, R. F. Stallard, and J. M. Edmond. 1981. Plankton metabolism and carbon processes in the Amazon River, its tributaries, and floodplain waters, Peru-Brazil, May-June 1977. Ecology, 62: 1622-1633.