1. Coupling of Carbon, Biogeochemical, and Hydrological Cycles: A Fluvial Perspective Jeff, Alex, Vicky, Anthony, Emilio e seus amigos Santarem

3. Soils Rivers Streams Atmosphere Dams Coastal Zone Floodplains Riparian pCO 2, as the “end member” of metabolic and transport processes, is a common currency for coupling of cycles CO 2 ↑ Outgassing

4. As of Manaus Science Conference 2002 CO 2 Outgassing ~ (conservative) C Sequestration 15 0 5 10 20 25 30 JFMAMJJASOND CO 2 Evasion (Tg C mo -1 ) T (>100m) S (<100 m) MF MC  : 1.2 ±. 3 Mg C ha -1 y -1 (basin ~.5 Gt y -1 ) Soil CO 2 Soil DOC Litter- fall Macro- phytes 0% 10% 20% 30% 40% Plankton Sources & Implicit Dynamics? Can we “better” constrain the outgassing estimation, as f([pCO 2 ], transfer coefficients)? What are the whole network source and transport dynamics (by region and by landscape structure)?

5. MAO Ji-P RB Jur Snt AF Pach Rede Beija-Rio

6. Assuming likely OC concentrations: 0.3-0.6 Gt of carbon “buried” per ENSO event in the (foreland) Amazon, 0.8-2.5 Gt “lost” globally?? ENSO-orchestrated C Supply and Sequestration …by Erosion-Sedimentation Processes (Rolf, Laurence, et al)

7. Annual Avg pCO 2 at Juruena (UFMT/Cornell; Johannes, Eduardo, Mark, et al) Seep (emergent ground water) –30000 ppm dry season –46000 ppm wet season (higher GPP) Headwater streams at weirs: 4000 ppm 2km down from headwaters: 2800 ppm Rohden Sul: 1130 ppm Rio Juruena: 830 ppm

8. Export of organic carbon from Igarape Asu, Central Amazonia (Maarten, Antonio, Martin et al. ) Stream OC export represents up to 20% of (lower) tower CO 2 flux estimates (pCO 2 not included, but from sparse measurements very high)

9. Isotopic Constraints on Organic and Inorganic Carbon Cycling … (Anthony, Emilio et al.) δ 13 C-CO 2 (o/oo) Δ 14 C-CO 2 (o/oo) “Multiple lines of evidence that respiration of contemporary organic matter (<5 y age) drives CO 2 outgassing in all river waters throughout the Amazon”

10. pCO 2 (water) (ppm) CO 2 evasion (umol m -2 s -1 ) 0 5 10 15 20 25 30 35 02000400060008000 Previous estimates of CO 2 outgassing from the Amazon Basin may be conservative, based on (1) the under- estimation of gas transfer velocity, (2) [pCO 2 ] in Rio Negro/elsewhere Pilot Experiments on Air-Water Exchange of CO 2 … (Simone, Scott, Elber et al )

11. Detection of carbon dioxide efflux from the rivers in the atmosphere (Joe, Jean, et al.) “ We did not see a river “signal” in the variation in d 13 C with CO 2 concentration in the ABL over the river; however, it was seen in the surface layer (Finding a low constant signal embedded in a fluctuating background is going to be difficult)”

12. …And the integral role of “hydrology in the landscape” (and the challenge to our ability to examine information) “VIC” hydrology /geospatial landscape dynamics model evaluation of the Ji-Parana basin (preliminary assessment “fly-through”) CENA (Danial, Vicky, Santiago,…), UW CEV (Bruce, Dave)

13. * Dissolved C is very high in small streams (sensitive to near-stream structure) Mobilization of POC from highlands “spirals” reactive C downstream Significant in-stream oxidation of “newer” OM Previous estimates of water/air transfer coefficient likely conservative Geography-specific “hotspots” (and “coldspots”); including Negro/NW sector (requiring multi-scale understanding) And the power and necessity of emerging information technologies to even evaluate and transmit such complex information “While we want to be careful and much work is in progress, continued evidence suggests :