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1、The carbon cycle of Amazon rain forest contentRegional profile 1Analysis of necessity23Prospect4The influencing factors of carbon cycle1 Regional profile Amazon drainage basinSatellite image from NASA.The Amazon represents over half of the planets remaining rainforests,20% of the total forest areaAm
2、azonian forests are estimated to have accumulated 0.62 0.37 tons of carbon per hectare per year between 1975 and 1996Amazonian evergreen forests account for about 10% of the worlds terrestrial primary productivity and 10% of the carbon stores in ecosystems2 Analysis of necessityIn a typical year the
3、 Amazon absorbs 1.5 *108t carbon dioxide2.1 biomass in Brazilian AmazoniaFigure 1 The spatial distribution of biomass in Brazilian Amazonia. a, RADAMBRASIL wood volumes converted to biomass with equations from refs 18, 19 (low estimate). b, RADAMBRASIL volumes converted to biomass (from ref. 21) (hi
4、gh estimate). c, Biomass interpolated from 56 sites (medium estimate).medium estimateforests recovered 70% of their original biomass in 25 years and the remaining 30% over the next 50 years3 The influencing factors of carbon cyclevClimatic factorsGlobal warming El Nino and La Nina Events Drought vfi
5、re hazard vVolcano eruption vHuman activity Land use patterns Industrial processes. Human life Nature factorsinterannual variations of the atmospheric CO2 concentrationSource or sink?Human factorssourceTemperature precipitation3.1 Related conceptsvNPP(net primary production) vNEE(net ecosystem excha
6、nge） vNEP（net ecosystem production） vRs（respiration） vRa(Autotrophic respiration) vRh（heterotrophic respiration) vNPP=GPP-Rplant vNEE=Rh-(GPP-Ra) vNEE=Rh-NPP3.2 Modes of actionNPPNEPRsRsRaRa RhRh NEECO2precipitationtemperatureSOCPhotosynthesis3.3 global warming:temperatureco2 couplingFig. 2. Detrend
7、ed anomalies of the atmospheric CO2 growth rate, tropical (24S to 24N) land-surface air temperature, and tropical land precipitation. The precipitation anomalies are reversed in sign for easier comparison with the CO2 growth rate and temperature. The background shading shows the occurrence and inten
8、sity of El Nio events as defined by the MEI1 C tropical temperature anomaly leading to a 3.5 0.6 Petagrams of carbon per year (PgC/y) CO2 growth- rate anomaly on average0.70.5(Multivariate ENSO Index)0.30.30.40.33.4 Temperature precipitation NPP、Rh、NEE coupling 75%55%83%3.5 Effects of global warming
9、 on terrestrial ecosystem carbon cycle.v With global warming, the ecological system NPP of low latitude area generally decreased v Climate warming can increase soil respiration rate, but with the passage of time, the effect that will be more and more weak showed some adaptability v Climate warming c
10、an increase land vegetation ecosystem carbon pool v Climate warming can speed up the litter production, but also increase the decomposition rate of litter v soil carbon of Low latitude area ecosystem still to increase due to the Supplement from the vegetation carbon pool v The low latitude area perf
11、ormance of carbon sequestration because the vegetation carbon pool accumulation over the soil carbon release 3.6 Amazon trophic forest：Source-sink? -1.7（ sink）-1.5Positive values indicate sourcesnegative values Indicate sinks.Fig. 4.Residual carbon flux anomalies estimated by the difference between
12、the observed atmospheric CO2 growth rate and those estimated from tropical land-surface temperature anomalies with a linear regression model3.6 ENSO to sink-sourceFigure 2 Net ecosystem production across the Amazon Basin. Spatial variability in net ecosystem production (gCm-2 yr-1) in the combined s
13、imulation of transient climate and transient atmospheric CO2 during three phases of El Nino/Southern red 、borrow 、yellow source Blue、green sink9.6-6.2-2.2=1.2 mols-1m-24、Prospect If the earth had no ”lung”?A 2009 study found that a 4 C rise in global temperatures by 2100 would kill 85% of the Amazon
14、 rainforest while a temperature rise of 3 C would kill some 75% of the Amazon.It concludes that the forest is on the brink of being turned into savanna or desert, with catastrophic consequences for the worlds climate.Reference 1 M. Keller .et al.,2001. Investigating the Carbon Cycle of the Amazon Fo
15、restsJ.GLOBAL CHANGE,45:15-19.2 J.E. Richey. et al.,2001. Land Use Changes and the Biogeochemistry of River Corridors in AmazonJ. GLOBAL CHANGE,45:19-22.3 Hanqin Tian.et al.,1998. Effect of interannual climate Variability on carbon storage in ecosystemsJ.NATURE,396:664-667.4 Weile Wanga.et al.,2013. Variations in atmospheric CO2 growth rates coupled with tropical temperatureJ. PNAS,110(32):61-66.5 John Grace.et al.
