Daniel Metcalfe Oxford University Centre for the Environment danieltcalfe@ouce.ox.ac.uk

1. Comprehensive monitoring of carbon allocation and cycling across the Amazon basin Daniel Metcalfe Oxford University Centre for the Environment daniel.metcalfe@ouce.ox.ac.uk

2. Objectives • Establish baseline of current forest carbon storage and allocation • Monitor ongoing changes in forest carbon cycling

3. Increasing CO2 “fertilizer” in the atmosphere

4. SENSITIVITY: TEMPERATURE Malhi and Wright (2004), Philosophical Transactions of the Royal Society

5. ↓ precipitation ↑ temperature ↑ atmospheric CO2 levels ↓ photosynthesis & ↑ soil respiration ↑ terrestrial CO2 emissions ↑ replacement of forest with savannah IPPC 2007 working group 1 report

6. Dry seasonlength Current trends: spatial variation - +

7. Caxiuana Iquitos Tambopata Kosnipata Tanguro Noel Kempff Field Sites • Comparisons • Drought • Soil type • Fire • Altitude

8. Ecosystem respiration Net primary production Rleaf Mleaf Soil CO2 efflux partitioning Pcanopy Rsoil Rstem Pstem Rlitter Mstem Rroots Rsoil Rcwd Proot Rmycorrhizae Mroot Rsom Constructing bottom-up carbon budgets

9. Constructing bottom-up carbon budgets

10. Equipment contruction & installation

11. Ecosystem respiration Net primary production Rleaf Mleaf Pcanopy Rstem Pstem Mstem Rsoil Rcwd Proot Mroot

12. Mleaf Pcanopy Pstem Mstem

13. Foliagedensity

14. Classification

15. Outputs

16. Specificleafarea

17. Threshold image to calculate area Fill in eaten leaf area to quantify herbivory

18. Leaf morphology

19. Variation with canopy height

20. Leaf dark respiration

21. Leaf light respiration

22. Ecosystem respiration Net primary production Rleaf Mleaf Pcanopy Rstem Pstem Mstem Rsoil Rcwd Proot Mroot

23. Stem Dynamics • Measurements • Belowandabove 10cm DBH • Basic data (species, DBH, height wood density) • Mode of death • Respiration......basal vs contruction respiration Respiration Growth

24. 18 16 1.22 ± 0.42 Mg ha-1 yr-1 14 12 10 8 No. plots 6 4 2 0 -4 -3 -2 -1 0 1 2 3 4 5 6 Biomass change / Mg ha-1 yr-1 Current trends: Increasing biomass Histogram of rate of biomass change over the 1980s and 1990s as observed in 59 RAINFOR plots. The mean change is 1.22±0.42 Mg biomass ha-1 year-1. From Baker et al (2004), Philosophical Transactions of the Royal Society of London.

25. Annual rate of stem mortality/recruitment (%) Year Current trends: Increasing dynamism Changes in tree recruitment (green) and mortality as observed in RAINFOR old-growth forest plots in recent decades. Forests appear to be becoming Increasingly dynamic. From Phillips et al (2004)

26. Ecosystem respiration Net primary production Rleaf Mleaf Pcanopy Rstem Pstem Mstem Rsoil Rcwd Proot Mroot

27. Ecosystem respiration Net primary production Rleaf Mleaf Pcanopy Rstem Pstem Mstem Rsoil Rcwd Proot Mroot

28. TECHNIQUES: RHIZOTRONS In situ measurement High temporal frequency Record root growth, mortality, longevity

29. RHIZOTRONS: CONVERTING LENGTH TO MASS roots • Calculate cross-sectional root area • Multiply area by length/width of plot to derive volume • Multiply volume by root density Frequent root mass production (t ha-1) rhizotron screen Source: Bernier & Robitaille. (2004), Plant and Soil.

30. TECHNIQUES: INFRA-RED GAS ANALYZER IRGA Record soil respiration Remove litter, measure respiration again Remove soil core, roots from core. Measure root respiration. Subtract root and litter respiration from total soil respiration isolate litter contribution estimate root contribution estimate residual respiration (i.e.: from soil organic matter) CO2

31. No litter Control 2 × litter Control No roots No roots or mycorrhizae Soil CO2 efflux partitioning

32. Key websites • The Amazon Forest Inventory Network: http://www.geog.leeds.ac.uk/projects/rainfor/ • Project for the Advancement of Networked Science in Amazonia: http://www.eci.ox.ac.uk/projects/panamazonia/ • Large Scale Atmosphere-Biosphere Experiment in Amazonia: http://www.lbaeco.org/lbaeco/ Daniel Metcalfe daniel.metalfe@ouce.ox.ac.uk

33. Caxiuana Iquitos Tanguro Andes Transect Noel Kempff

34. The current effect of CO2 fertilizer on terrestrial ecosystems Lloyd (1999), Functional Ecology.

35. Synthesis of results Good evidence for drought-induced decline in photosynthesis, but this is balanced out by a decline in soil CO2 efflux.What accounts for inter-annual patterns? Some evidence for drought-induced changes in mortality and reproduction, but massive variability. Overall, the forest appeared suprisingly resilient to drought BUT Other poorly quantified components of the carbon cycle

36. Robustness of the modelled “Amazon drought”

37. Short-term model predictions: Climate & Carbon

38. Differences amongst regions

39. Long-term model predictions: Vegetation

40. Long-term model predictions: vegetation

41. ↑ temperature ↓ precipitation ↓ photosynthesis & ↑ soil respiration ↑ atmospheric CO2 levels ↑ terrestrial CO2 emissions ↑ replacement of forest with savannah e.g.: see Cox et al. (2000), Nature.

42. Results from the first two years: soil moisture

43. Results from the first two years: canopy properties

44. Results from the fifth year: canopy properties

45. Results: tree dynamics Mortality over 3 years Control: 2.4% of pop. TFE: 1.5% of pop. BUT Control: 1.3 t C ha-1 TFE: 2.1 t C ha-1

46. ↑ temperature ↑ atmospheric CO2 levels ↓ precipitation ↓ photosynthesis & ↑ soil respiration ↑ terrestrial CO2 emissions ↑ replacement of forest with savannah e.g.: see Cox et al. (2000), Nature.

47. Overlooked components of the C cycle Leaf dark respiration

48. TEMPORAL TRENDS: RESPIRATION Model uncertainty caused mainly by lack of information about below-ground processes Source: Lloyd & Prentice (1998), Nature.

49. RHIZOTRONS: RESULTS Additional surge on the Drought plot coinciding with the first big rain events surge in both growth and mortality during the wet season ? ? ?

50. SYNTHESIS: ABOVE- & BELOW-GROUND DATA Treatment differences in stem wood production are relatively small compared to root and litter fall production The drought treatment alters ecosystem carbon cycling, e.g.: the balance between carbon entering the soil via litter fall, and leaving via microbial respiration