Developing a model of methane (and other GHG)

emissions from highly organic soils

Jo Smith & Helen FlynnSchool of Biological Sciences

University of Aberdeen

SEERAD / NAW Project with

What will happen to SOC stocks in 21st Century? Grassland,

A1FI

Factors not included in ROTH-C or SUNDIAL

• Effects of soil pH• Methane emissions• Losses as dissolved organic carbon

ROTH-C (Jenkinson et al, 1977); SUNDIAL (Bradbury et al, 1993; Smith et al, 1996)

Model to simulate C and N

cycling in organic soils

Estimates of changes in C and N balance of organic

soils from Countryside surveys

of Scotland and Wales

C loss fromaccelerated erosion of

organic soils

Best-practice guidelines on

the agricultural use of organic

soils

Best-practices guidelines on

effects of conversion to

forestry

= use of model outputs= flow of dataDistribution of

organic soils

Effects of land-use and climate change on GHG emissions from

organic soils

Effects of land use and climate

change on release of dissolved

organic matter from

organic soils

Some models of methane emissions

Wetland-DNDC Zhang et al, 2002

Arah & Stephen model Arah & Stephen, 1998

Linked ForHyM2 Clair et al, 2002

TEM and methane Zhuang et al, 2003; Cao et al, 1998

Kettunen model Kettunen, 2002

Ecosystem source model Christensen et al, 1996

Waterlevel

MoistureTexture

Oxy

gen

Tem

pera

ture

pH

DecompositionDrivers

WaterModule

Tem

pera

ture

Module

pH Module

TextureModule

Oxy

gen

Mod

ule

Soillevel

INPUTSMax.Water

levelRain,PET

INPUTSAir Temp

INPUTSSoil

Parameters

Carbon Componentof Organic Soils Model

BIO HUM IOM

CH4 CH4

MethaneOxidation

Meth.Oxid.

EXTERNAL• Dynamic hydrology model (eg. SWIM)• HOST classes• Measurements

Decomposition

CO2 CO2

INPUTSNPP

LU Type

EXTERNAL• Dynamic model (eg. BIOTA)• Static model (eg. MIAMI)• Satellite estimates

DPMRPM

DOC

Waterlevel

MoistureTexture

Oxy

gen

Tem

pera

ture

Acidity

DecompositionDriversTe

mpera

ture

Module

Acidity Module

TextureModule

Oxy

gen

Mod

ule

Soillevel

INPUTSMax.Water

levelRain,PET

INPUTSNPP, LU Type

EXTERNAL• Dynamic model (eg. BIOTA)• Static model (eg. MIAMI)• Satellite estimates

INPUTSAir Temp

INPUTSSoil

Parameters

HUM

Nitrogen Componentof Organic Soils Model

DecompositionIOM

N2O

& N2

EXTERNAL• Dynamic hydrology model (eg. SWIM)• HOST classes• Measurements

Leached N

BIO

RPM DPM

WaterModule

NO3-

NH3

NH4+

Plant N

What will happen to SOC stocks in 21st Century? Grassland,

A1FI

Pete Smith1, Jo Smith1, Helen Flynn1, Ken Killham1, Ignacio Rangel1, Ronnie Milne2, Ute Skiba2, David Fowler2, Mike Billett2, Steve Chapman3, Willie Towers3, John Bell3,

Ann Malcolm3, David Lumsdon3, Bente Foereid3, Brian Reynolds4, Chris Evans4, Zoë Frogbrook4, Ian

Bradley5, Marianne McHugh5, Pete Falloon6

1 School of Biological Sciences, University of Aberdeen2 Centre for Ecology and Hydrology (Edinburgh)3 Macaulay Institute4 Centre for Ecology and Hydrology (Bangor)5 National Soils Resources Institute, University of Cranfield6 Rothamsted Research