1. The Carbon Cycle: Global to local Ruth Varner, PhD

2. Atmospheric CO 2 at Mauna Loa Keeling, C.D. and T.P. Whorf. 2004. Atmospheric CO 2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.

3. The Earth System The Earth is a system made up of components. There are feedbacks between these components. These relationships can be used to predict past and future changes in the environment. The Carbon cycle is an important Earth System.

5. Formation of Fossil Carbon Coal: from the remains of plants (mainly from Carboniferous period) Oil: from marine organisms that were buried under ocean or river sediments Natural Gas: was originally oil; higher temperature and pressure converted it to primarily methane

7. Combustion Burning hydrocarbons produces CO 2 and CO: CxHx + O 2  CO 2 + H 2 O (if enough O 2 ) Complete combustion Hydrocarbon + oxygen = carbon dioxide and water CxHx + O 2  CO 2 + CO + H 2 O (if not enough O 2 ) incomplete combustion Hydrocarbon + oxygen = carbon dioxide and carbon monoxide and water

9. Photosynthesis – carbon fixed from inorganic CO 2 to organic molecules (sugars) 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 chlorophyll, sunlight Respiration – sugar is “burned” as part of a metabolic process that consumes oxygen and produces energy (ATP) – decomposition results in respiration C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + energy Biological uptake/release of CO 2

10. From the Atmosphere: Inorganic C in the Ocean CO 2 (atm) ↔ CO 2 (aq) ↔ HCO 3 - + H + ↔ CO 3 2- + H+ ↔ CaCO 3 ↔ seds

11. Carbon dioxide in the oceans Calcareous skeleton carbon – can be dissolved or deposited

13. UNH/NOAA-PMEL CO 2 Buoy in Gulf of Maine In sea water In overlying atmosphere

18. Terrestrial Carbon Soil carbon is released through respiration : root and microbial (decomposition) Plants respire CO 2 Plants also fix carbon through photosynthesis

19. Terrestrial Carbon Biological uptake/release of CO 2 Photosynthesis – carbon fixed from inorganic CO 2 to organic molecules (sugars) 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 chlorophyll, sunlight Respiration – sugar is “burned” as part of a metabolic process that consumes oxygen and produces energy– decomposition results in respiration C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + energy

20. Global network of flux towers used to measure CO 2 exchange between ecosystems and the atmosphereGlobal network of flux towers used to measure CO 2 exchange between ecosystems and the atmosphere Sites also include measurements on vegetation, soils, hydrology and meteorology.Sites also include measurements on vegetation, soils, hydrology and meteorology. Information available to researchers, students and educators.Information available to researchers, students and educators. F LUXNET

21. http://www.fluxnet.ornl.gov/fluxnet/index.cfm

22. Total ecosystem respiration = R soil + R leaf + R stem + R cwd Rsoil Rstem Rleaf Rcwd

23. R soil = R root + R decomp Soil CO 2 efflux is a measurement of the R soil that reaches the atmosphere

24. Measuring Soil CO 2 Efflux Manual chamber measurements Autochamber measurements

25. Volcanic CO 2 Subduction of limestone at plate boundaries Carbonotype: watery low temperature lava

26. Oceans +2 Pg yr -1 Atmosphere +2 Pg yr -1

27. FACE Duke Forest, Chapel Hill, NC Carbon Fertilization ?

28. FACE site locations

29. Carbon cycling in temperate ecosystems

32. c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 Temperate poor fen in southeastern New Hampshire (43 12.5’N, 71 3.5’W)Temperate poor fen in southeastern New Hampshire (43 12.5’N, 71 3.5’W) Area: 1.7 haArea: 1.7 ha Peat depth: 2-4.5mPeat depth: 2-4.5m Mean annual precipitation: 1100 mmMean annual precipitation: 1100 mm Mean annual temperature: 8.1 CMean annual temperature: 8.1 C Mean growing season T: 14.9 CMean growing season T: 14.9 C Biologically active season from April- OctoberBiologically active season from April- October Sphagnum dominatedSphagnum dominated Other important species are leatherleaf, blueberry, sedgeOther important species are leatherleaf, blueberry, sedge

33. Select from chamber IRGA LI6262 Pump MFC Select to chamber Control System Box Clear Lexan Boxes 0.07 – 0.08 m 3 (5) 0.14 – 0.16 m 3 (5) Automated Chamber Fluxes Distributed Return Manifold Fans mix headspace A flux every 20 minutes 96 fluxes per day

34. Manual Chamber Fluxes –CH 4 : Grab samples taken during chamber measurements; analyzed on an GC-FID –CO 2 : IRGA (LiCor 6200) analyzes air from chamber headspace; calculates NEE

35. 19952007 Vegetation survey maps of Sallie’s Fen from 1995 and 2007.

36. Research Questions?