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Autumn 2004

Autumn 2004. WP1 : Comparison between regenerations. Total respiration. RTOT(micromoleCO 2 /m 2 /s). GP(micromoleCO 2 /m 2 /s). advanced. GP. recent. Bare peat. NEE (micromoleCO 2 /m 2 /s). NEE.

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Autumn 2004

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  1. Autumn 2004

  2. WP1 : Comparison between regenerations Total respiration RTOT(micromoleCO2/m2/s) GP(micromoleCO2/m2/s) advanced GP recent Bare peat NEE (micromoleCO2/m2/s) NEE Difference statistically significant between the three situations with the Kolmogorov Smirnov test.

  3. WP1 : Seasonal variation of the vegetation Plot 1 Plot 3 Seasonal variation of the average surface of photosynthesis (mm2) E. angustifolium Variation of the number of leaves (recent regeneration : E. angustifolium) Julian day Julian day Seasonal variation of the average surface of photosynthesis (mm2) E. vaginatum Variation of the total surface of Photosynthesis (m²) Julian day Julian day Julian day

  4. Seasonal variation of the vegetation LAI of E. angustifolium (m²/m²) in recent regeneration LAI of E. vaginatum, C. nigra, V. oxycoccos (m²/m²) in advanced regeneration Julian Day Julian Day Density*surface covered by Sphagnum sp. and P. strictum in advanced regeneration Density*surface covered by Sphagnum sp. and P. strictum in recent regeneration Julian Day Julian Day

  5. WP1 : Le Russey, Rtot=f(temperature) Recent and advanced Y=a*ebTair RTOT(micromoleCO2/m2/s) Tair Recent and advanced Y=a*ebT10cm RTOT(micromoleCO2/m2/s) T10cm

  6. Simulation of CO2 fluxes for recent and advanced regeneration Model equations for recent and advanced regenerations GPM=GPMTo*exp(-(((Tair-To)/i)^2)) GP=(GPM*(LAI+g*(Ss*Ds+Sp*Dp)*H))+h R=Ra+Rh Ra=a*(LAI+c*(Ss*Ds+Sp*Dp)*H)*exp(b*Tair) Rh=d*exp(e*(-WT))*exp(f*Tair) NEE=GP-R Variables LAI= Leaf area index for vascular plants Ss= surface covered by Sphagnum sp Ds= density/density max per Sphagnum sp Sp= surface covered by Polytrichum Strictum Dp= density/density max per Polytrichum Strictum Tair= air temperature measured in the chamber WT= Water table level H= Humidity / Humidity max (index 5)

  7. Simulation of CO2 fluxes for recent and advanced regeneration Recent regeneration : NEE Values of parameters established by the software NEE simulated(micromoleCO2/m²/s) NEE measured Advanced regeneration : NEE NEE simulated(micromoleCO2/m²/s) NEE measured

  8. Simulation of CO2 fluxes for the bare peat situation Bare peat :Rtot Rtot simulated (micromoleCO2/m²/s) Rtot measured Model equations adapted for the bare peat situation, with the total respiration. R=a*(-WT)^2+b*(-WT)+c*exp(f*Tair) Variables Tair= air temperature measured in the chamber WT= Water table level Values of parameters established by the software

  9. Diurnal variation of CO2 Recent regeneration Advanced regeneration sink Par (micromole/m2/s) NEE measured source NEE (micromoleCO2/m2/s) NEE simulated

  10. WP1 : Methane measurement

  11. WP1 : Le Russey, methane fluxes Seasonal variation of CH4 fluxes per plot (recent regeneration) nmoleCH4/m²/s • Variability between plots. • first prelevement with the lowest water table level. • Bare peat situation : • Day 178 : 4,4nmoleCH4/m²/s • Then, WT = 0, no more fluxes. Seasonal variation of CH4 fluxes per plot (advanced regeneration) nmoleCH4/m²/s

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