Developing a model of methane (and other GHG) emissions from highly organic soils Jo Smith & Helen Flynn School 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 from accelerated 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 data Distribution 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-DNDCZhang et al, 2002 Arah & Stephen model Arah & Stephen, 1998 Linked ForHyM2Clair et al, 2002 TEM and methane Zhuang et al, 2003; Cao et al, 1998 Kettunen modelKettunen, 2002 Ecosystem source modelChristensen et al, 1996

Water level Moisture Texture Oxygen Temperature pH Decomposition Drivers Water Module Temperature Module pH Module Texture Module Oxygen Module Soil level INPUTS Max.Water level Rain,PET INPUTS Air Temp INPUTS Soil Parameters Carbon Component of Organic Soils Model BIO HUM IOM CH 4 Methane Oxidation Meth. Oxid. EXTERNAL Dynamic hydrology model (eg. SWIM) HOST classes Measurements Decomposition CO 2 INPUTS NPP LU Type EXTERNAL Dynamic model (eg. BIOTA) Static model (eg. MIAMI) Satellite estimates DPMRPM DOC

Water level Moisture Texture Oxygen Temperature Acidity Decomposition Drivers Temperature Module Acidity Module Texture Module Oxygen Module Soil level INPUTS Max.Water level Rain,PET INPUTS NPP, LU Type EXTERNAL Dynamic model (eg. BIOTA) Static model (eg. MIAMI) Satellite estimates INPUTS Air Temp INPUTS Soil Parameters HUM Nitrogen Component of Organic Soils Model Decomposition IOM N 2 O & N 2 EXTERNAL Dynamic hydrology model (eg. SWIM) HOST classes Measurements Leached N BIO RPM DPM Water Module NO 3 - NH 3 NH 4 + Plant N

What will happen to SOC stocks in 21st Century? Grassland, A1FI

Pete Smith 1, Jo Smith 1, Helen Flynn 1, Ken Killham 1, Ignacio Rangel 1, Ronnie Milne 2, Ute Skiba 2, David Fowler 2, Mike Billett 2, Steve Chapman 3, Willie Towers 3, John Bell 3, Ann Malcolm 3, David Lumsdon 3, Bente Foereid 3, Brian Reynolds 4, Chris Evans 4, Zo ë Frogbrook 4, Ian Bradley 5, Marianne McHugh 5, Pete Falloon 6 1 School of Biological Sciences, University of Aberdeen 2 Centre for Ecology and Hydrology (Edinburgh) 3 Macaulay Institute 4 Centre for Ecology and Hydrology (Bangor) 5 National Soils Resources Institute, University of Cranfield 6 Rothamsted Research