“Kutsch, Bahn, Heinemeyer, CUP 2009” - JULES

“Kutsch, Bahn, Heinemeyer, CUP 2009”

Modelling upland peat carbon:past present and futureIf only...carbon molecules could bite!“Thinking big, working small and modelling in between”Dr Andreas Heinemeyer andreas.heinemeyer@york.ac.ukUniversity of York, Environment Department

Current models & peatCurrently, we cannot adequately predict peatland soil C stocks and C dynamicsFrom: ISLSCP IIFrom: SDGVM(kg C m -2 )Most current models lack:• Holocene peat accumulation• total peat column decomposition• peat depth dynamics• dynamic water table• vegetation feedbacks• topography effects~4.6 Mt C lacking a pedogenesis concept

Feedback implicationsSo, how much can we trust current model SOC - climate feedbacks (CO 2 & CH 4 )?IPCC, 2007

MILLENNIA peat modelMAT (°C)8765432MAT_CONSTMAP_CONSTMAT_ORNLMAP_ORNL350030002500200015001000MAP (mm)Cohort modelBasic climateLong-term spin-upDynamic water tableDynamic vegetationLitter quality15000001000200030004000500060007000Years since peat initiation8000900010000C-RootC-Soil

MILLENNIA: current C stocksClimate Research, 2010

MILLENNIA: SOC agePeat depth (cm)2802402001601208040Modelled column ageMeasured column agePeat C increment100806040200C increment (gC yr -1 )0-201000080006000400020000Time (yrs; 0 = Today)

MILLENNIA: topography150NorthEastSouthWest1. Temperature2. Runoff3. ErosionPeat depth (cm)1005000°valleytop2.5° 7.5° 17.5° 2.5°valleyAspect (°)bottomModel vs. Site dataModel vs. Site dataTerrain informationElevation (m) Slope (°) Aspect (°) SOC (kgC m -2 ) SOC (kgC m -2 ) Peat Depth (cm) Peat Depth (cm)500-700 0-5 N 131.86 121.37 240.02 233.50500-700 0-5 S 124.66 66.77 227.28 151.00500-700 5-10 N 129.18 76.46 235.34 145.33500-700 5-10 S 103.78 42.43 190.48 87.00500-700 10-25 N 91.21 51.97 168.54 105.00500-700 10-25 S 22.25 29.40 37.01 65.50

MILLENNIA: future C dynamicsTemperature rise (+2 or +4°C)Precipitation change (±25 % mm)C StocksC fluxesSoil Carbonwarm & wetwarm & drywarm & dryCO 2Water TableCH 4warm & wet

Model inter-comparison: MigneintClimate Research, 2010= to 20 cm peat/ year!Temperature!

Major UK Soil TypesRendzinas Brown Earths Gleys Podsols PeatsRequires dynamic changes in both, percentage and amount of texture

Future modelling: pedogenesisMineral --------------------- > PeatCO 2 & CH 4Pedogenesis:Mull – Moder - MorClaySiltSandPassiveSlowAcrotelmsoil mixingActiveRootsStonesH2OSpaceWater Table Depth(WTD)=height of acrotelmClaySiltSandPassiveSlowActiveRootsStonesH2OSpacebulk densityWater TableMineralOrganichydrologyCatotelmClaySiltSandPassiveSlowActiveStonesH2OSpaceClaySiltSandPassiveSlowActiveStonesH2OSpaceNew SDGVM CENTURY-type soils module

Thank you !Acknowledgements:RSPB, CCW, EU LIFE project,Severn Trent Water, United Utilities, NE,Edinburgh aircraft team,Bob Baxter, Brian Huntley, Fred Worrall,Mark Garnett, UKPopNet staff,Simon Croft, Pippa Gillingham,Project students and many others...!

Collar insertion and ‘lost’ root flux1.0Lost fluxForest ~10%3.01.0Root lengthMoorland ~40%50Lost flux (µmol m -2 s -1 )0.80.60.40.2Root length2.52.01.51.00.5Root length (km m -2 )Lost flux (µmol m -2 s -1 )0.80.60.40.2Lost flux40302010Root length (km m -2 )0.00.00 5 10 15 20Collar Cut insertion soil depth depth (cm) (cm)0.00 5 10 15 20 25Cut soil depth (cm)04Root lengthGrassland ~20%125Lost flux (µmol m -2 s -1 )321Lost flux100755025Root length (km m -2 )00 5 10 15 20 25Cut soil depth (cm)-

‘Breaking down’ flux components128Flux tower 1Flux tower 2ChamberDark respirationSoil respiration(Night-time) C releaseCO2 flux (µmol m -2 s -1 )40-4-8-12(Day-time) C uptake-1616/0812:0017/0800:0017/0812:0018/0800:0018/0812:0019/0800:0019/0812:0020/0800:00

Scaling up from plot to landscape106CO2 flux (µmol m -2 s -1 )2-2-6-10-14-18-22ChamberFlux TowerAir craft25/0812:0025/0813:1225/0814:2425/0815:3625/0816:4825/0818:0025/0819:12