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Sustainable Land Management Sustainable Land Management through Soil Organic Carbon through Soil Organic Carbon Management and SequestrationManagement and Sequestration
The GEFSOC Modelling System
Mohamed Sessay
Eleanor Milne
Overview of PresentationOverview of Presentation
• Background
• Why assess SOC stocks and change
• Regional Approaches
• GEFSOC Project: Aims and Objectives
• Methodology: GEFSOC Project Approach
• Final Output
BackgroundBackground
Importance of Soil Organic Carbon
Soils represent largest terrestrial stock of C, holding between 1400 x1015 g (Post et al 1982) and 1500 x 1015 g C (Batjes, 1996)
Approximately 2x the amount in atmosphere and 3x amount in terrestrial vegetation
Majority of C is held in form of soil organic carbon (SOC) (Batjes & Sombreck, 1997)
Changes in terrestrial SOC stocks (both increase and decrease) can be of global significance and may either mitigate or worsen climate change
SOC is vital for ecosystem functions with major influence on:
- Soil structure, Water holding capacity
- CEC
- Ability to form complexes with metal ion
- Fertility (to store nutrients)
- Above and below ground biodiversity
Why Assess SOC Stocks and Changes?Why Assess SOC Stocks and Changes?
Knowledge of SOC stocks and changes would help us device plans for:
Appropriate management of soils to increase SOC levels to increase productivity and sustainability of agricultural systems
The sustainable management of ecosystems
The mitigation of GHG emissions
The likely impact of climate change on soils/ecosystems in the future (Jones et al 2004)
The Kyoto ProtocolThe Kyoto Protocol
The Kyoto Protocol - CO2 emissions can be offset against removal of C from the atmosphere
1st commitment period 2008 – 2012
Article 3.3, forestry activities Article 3.4, management of agricultural soils
Changes before 2008?
UNFCCC -Inventories of CO2 emissions from LUC
Why assess SOC Stocks and Changes?Why assess SOC Stocks and Changes?
Native Ecosystem
Agriculture
SOC decline
Rothamsted long term experimentsVersailles long term experiments
SOC is sensitive to changes in land use
Why assess SOC Stocks and Changes?Why assess SOC Stocks and Changes?
Knowledge of SOC stocks and changes would help us device plans for:
Appropriate management of soils to increase SOC levels to increase productivity and sustainability of agricultural systems
The sustainable management of ecosystems
The mitigation of GHG emissions
The likely impact of climate change on soils/ecosystems in the future (Jones et al 2004)
Important Areas GloballyImportant Areas Globally
Rates of land use change greatest in the tropics
Feed 70% of the population (Lal and Sanchez 1992)
Increasing demand for land will be met by converting forest and pasture – C release
~ 26% of global SOC stocks are in the tropics (Batjes 1996)
Relatively little information on soils and how they react to land use change
The Tropics
Important Areas GloballyImportant Areas Globally
Low SOC stocks per unit area
Occupy ~47% of land surface (Lal 2003)
Many areas are degraded with the potential for rehabilitation
Drylands
Problem of ScaleProblem of Scale
Plot Scale Many studies, site specific, limited value
Global Scale
Regional and National Scale
Allows consideration of varying land use policy, relevant to resource management
Informative, limited affect on policy at ground level
A generically applicable systems for estimating SOC stocks at national or regional scale is necessary to:
Increase the accuracy of global estimates of SOC stocks and changes
Understand the consequences of land use change for the global C cycle
Understand the GHG mitigation potential of changes in land use/land management
Identify geographic areas with potential for C release or sequestration
Allow countries in tropical and arid areas to take advantage of opportunities presented through global carbon trading, (CDMs)
Regional ApproachesRegional Approaches
Approaches used estimate changes in SOM/SOC include
IPCC inventory method:- Series of factors (climate, soil type, history, tillage &
productivity) 20 year period Identifies changes between first and last year of the 20 year
period Simple accounting method Soil C stock is a function of soil C under native vegetation and
changes in land use or land management
Regional ApproachesRegional Approaches
Statistical approaches:
Regression based approaches (Gupta and Rao 1994, Smith et al 2000, 2001)
Regression approaches based on spatial soil databases (Kern and Johnson 1993, Kotto-Same et al 1997)
Local variability in soil conditions
Process Based Modelling Approach
3. Dynamic SOM models linked to spatial data bases
Spatial DatabasesSimulatio
nmodel
ActiveSOM
SlowSOM
PassiveSOM
Residues
PlantGrowth
CO2 CO2CO2
CO2
CO2
Spatial Results
Aims of GEFSOC ProjectAims of GEFSOC Project
– To improve national assessment methodologies relating to land use options and UNFCC requirements and to support core activities of the GEF IEM OP and IPCC by developing and demonstrating a generic tool that quantifies impact of land use/management and climate change scenarios on carbon sequestration in soils at the national and regional scale
Specific Research ObjectivesSpecific Research Objectives
Identify and use long term experimental data sets to systematically evaluate and refine modelling techniques to quantify carbon sequestration potential in tropical soils
Define, collate and format national-scale soils, climate and land use data sets to use them in development of a coupled modelling-GIS tool to estimate soil carbon stocks
Demonstrate this tool by estimating current soil organic carbon stocks at the national and regional scale (using The Brazil Amazon, The Indo-Gangetic Plains, India, Jordan and Kenya as case studies) and to compare these estimates with the existing techniques of combining soil mapping units and interpolating point data
Quantify the impact of defined changes in land use on carbon sequestration in soils with a view to assisting in the formulation of improved policies to optimise resource use in the four case study countries Brazil, India, Jordan and Kenya
Case StudiesCase Studies
Brazilian Amazon
Jordan
Kenya Indogangetic Plains, India
MethodologyMethodology
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
GEFSOC Project ApproachGEFSOC Project Approach
Two soil organic carbon models were chosen
Roth-C (developed in the UK) is a SOM model that accounts for the effects of soil type, climate, moisture content and plant cover on turnover of organic C in soils. Uses monthly time-step to calculate total SOC and microbial biomass content
Century (developed in the United States) is a general ecosystem model which stimulates the dynamic of C, N, P and S in different plant/soil systems. Has plant productivity, water movement and nitrogen leaching sub models
Evaluated under many conditions (including forestry, grasslands and arable in the tropics)
Two of the most widely used SOM models
Good performance in comparison of 9 models (Powlson et al 1996, Smith et al 1997)
Used in regional applications
Model GIS linkage
Roth C
Century
Rothamsted Carbon Model (Roth C)Rothamsted Carbon Model (Roth C)
Decay
Decay Decay
Decay
BIO
HUM
CO2BIO
HUM
CO2
Decay
Decay
Organic
Inputs
DPM
RPM
Inert Organic Matter
DPM = decomposable plant material
RPM = resistant plant material
BIO = microbial biomass
HUM = humus
Colman and Jenkinson (1996)
Century Ecosystem Model (Century)Century Ecosystem Model (Century)
Parton et al (1987)
Stage 1. Model EvaluationStage 1. Model Evaluation
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
Stage 2. National DataStage 2. National Data
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
Stage 3: Model/GIS couplingStage 3: Model/GIS coupling
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
Graphical user interface
Program modules
IPCC
Stage 4: Current StocksStage 4: Current Stocks
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
Current land use
Global level information +
Landscape level
Stage 5. Future StocksStage 5. Future Stocks
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
COMPARE
STAGE 4. ASSESS CURRENT SOC STOCKS
For the year 2000
ASSIST POLICY FORMULATIONASSIST POLICY FORMULATION
EXISTING TECHNIQUES
STAGE 1. MODEL EVALUATION
Identify long term experimental
data sets
SOIL C MODELS
STAGE 3. SOM MODEL/ GIS LINKAGE
GIS
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 2. MODEL INPUT DATA
Collate & format national scale datasets of soils climate and land use
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
STAGE 5. ASSESS CHANGES IN SOC STOCKS
Quantify the impact of land use changes on c
sequestration in soil between 2000 - 2030
Regional carbon stocks: current and future
SOC stocks in the 0-20cm soil layer for the year 1990
SOC stocks (t C ha-1)
Regional carbon stocks: current and future
SOC stocks (t C ha-1)
SOC stocks in the 0-20cm soil layer for the year 2030
The Final OutputThe Final Output
A transferable system for estimating SOC stocks and changes in a range of soils and climatic conditions (The GEFSOC Modeling System), designed to help in formulating national and sub-national land management and carbon sequestration policy by:
(i) Quantifying current soil organic carbon stocks at national and sub-national level and
(ii) Analyzing the impacts of land management options on carbon storage , GHG emissions and sequestration possibilities
Website ReferenceWebsite Reference
The GEFSOC Modelling System can be downloaded free of charge via the project website
http://www.nrel.colostate.edu/projects/gefsoc-uk
And the UNEP website www.unep.org
And is accompanied by a use manual
THANK YOU
FOR
YOUR ATTENTION