Experiments Canada NORTH AMERICA Oklahoma Atlantic Pacific Ocean Ocean Bermuda EcoCELLs (UK) Gulf of in Nevad Mexico 233N a ANCER armino AC,C
Experiments Experiments EcoCELLs in Nevada Warming FACE, NC
Warming experiments Long-term:10 years One year,step change Warming:2C Warming:4C Clipping:Yearly Precipitation:doubled
Warming experiments Long -term: 10 years term: 10 years Warming: 2 Warming: 2 o C Clipping: Yearly Clipping: Yearly One year, step change One year, step change Warming: 4 Warming: 4 oC Precipitation: doubled Precipitation: doubled
Third Experiments Warming x Prec
Third Experiments Warming x Precipitation x Bioenergy
Carbon cycle-climate warming feedback 平 06 [Mauna Loa Data from Keeling and Whorf (1994)] 380 Global Temperatures 0.4 Annual Average 03 -Five Year Average 02 70 04 1960 19701980 19902000 Year 0.6 18601880190019201940196 9802000 Ecosystem
Carbon cycle-climate warming feedback [ Mauna Loa Data from Keeling and Whorf (1994) ] Year 1960 1970 1980 1990 2000 CO2 Concentration (ppmv) 310 320 330 340 350 360 370 380 Ecosystem + + +
Acclimation of soil respiration to warming Unclipped Clipped 40 6 a a:Unclipped 30 5 Isocline of full acclimation 20 10 3 Unwarmed 0 2 89 Warmed 40 30 0 20 b:Clipped 10 Isocline of full acclimation 4 Unwarmed -Warmed 苏 3 Unwarmed 百 Warmed 2 1 NDJFMAMJJASON NDJFMAMJJASON 15 20 25 30 35 Month Month Soil temperature(OC) Luo et al.2001 Nature
0 1 2 3 4 5 6 Soil temperature (oC) 5 10 15 20 25 30 35 Soil respiration ( μmol m-2 s-1 ) 0 1 2 3 4 5 Warmed Warmed Unwarmed Unwarmed Isocline of full acclimation Isocline of full acclimation b: Clipped a: Unclipped Luo et al. 2001 Nature Acclimation of soil respiration to warming Soil temperature (oC) 0 10 20 30 40 Unclipped Soil moisture content (%) 0 10 20 30 40 Clipped c Month Soil respiration (μmol m-2 s-1) 0 1 2 3 4 5 Unwarmed Warmed Month d e f N D J F M A M J J A S O N N D J F M A M J J A S O N a b