43 % of Earth’s terrestrial vegetated surface is degraded with limited capacity to supply benefits to humans. Degraded landscapes often result in lower Soil Organic Carbon and overall poor soil health. Understanding drivers of Land Degradation and processes of Soil Organic Carbon loss are key for informing effective interventions .

1. Need for Spatially Explicit, Robust
Assessments of Soil Organic Carbon
Leigh Ann Winowiecki and Tor-G. Vågen, World Agroforestry Centre (ICRAF)

2. Need for land restoration in sub-Saharan Africa
• 43 % of Earth’s terrestrial
vegetated surface is degraded
with limited capacity to supply
benefits to humans
• Degraded landscapes often result
in lower SOC and overall poor soil
health
• Understanding drivers of LD and
processes of SOC loss are key for
informing effective interventions
Source: ICRAF GeoScience Lab

3. Indicators for the assessment &
monitoring of ecosystem health:
1. Science based
2. Readily measurable (quantifiable)
3. Rapid
4. Based on field assessments across multiple scales
(plot, field, landscape, region)
5. Representative of the complex processes of for
example, land degradation, in landscapes

4. Understanding
Dynamics

5. Ecosystem Health Surveillance System

6. Systematic Assessments of Land and Soil Health
• The Land Degradation Surveillance
Framework (LDSF)
• Systematic field-based assessments of
multiple variables at the same geo-
referenced location
• Vegetation cover, land use, management, soil
properties, biodiversity, etc.
• Mapping of SOC at multiple spatial scales
• Allows for:
• Rapid assessments across diverse
landscapes
• Assessment of multiple drivers of land
degradation
• Targeted prioritization of interventions
• Cross site comparisons
• Production of high quality maps of key
indicators
http://landscapeportal.org/blog/2015/03/25/the-land-degradation-surveillance-framework-ldsf/

7. Assessing biophysical constraints to SOC storage
• There are inherent soil
properties that limit the
extent to which the soil
can store carbon.
• These constraints are
important to understand in
order to manage for
agricultural productivity
and to target interventions
to increase SOC in a
spatially explicit way.
Winowiecki, L., Vågen, T-G. and Huising, J. 2016. Effects of land cover on ecosystem services in Tanzania:
A spatial assessment of soil organic carbon. Geoderma.
(http://www.sciencedirect.com/science/article/pii/S0016706115000816).

8. Understanding
Vegetation Patterns using
Stable Carbon Isotopes
• Density plots of δ13C values for the
top- and subsoil samples for each of
the five Land Cover Classifications.
The black dotted vertical lines are
average δ13C for C3 vegetation,
−14‰ and for C4 vegetation, −26‰.
• Note the high variation in cropland,
which may reflect time since
conversion and types of crops
• This shift occurs between 5-19 years
Winowiecki, L. A., Vågen, T.-G., Boeckx, P., & Dungait, J. A. J. (2017). Landscape-scale assessments of stable carbon
isotopes in soil under diverse vegetation classes in East Africa: application of near-infrared spectroscopy. Plant and Soil.
https://doi.org/10.1007/s11104-017-3418-3

9. SOC and Erosion
Data from LDSF sites show
that increased erosion is
often driving the loss of SOC
in landscapes.
Photo credit: Joakim Vågen

10. National Soil Organic Carbon Assessments
Vågen et al. InReview. SOIL

11. Potential increases in
SOC stocks to achieve
targets set in the 4/1000
initiative
Example for Tanzania

12. § Maps of soil organic carbon
(SOC, top), soil pH (middle),
and sand content (bottom) at
5 m resolution (RMSEP values
were 1.3,0.2, 5). White areas
represent Agincourt Health
and Socio-Demographic
Surveillance System (AHDSS)
villages.
- Comparison with geology,
climate and vegetation
Vågen et al., 2018
https://dl.sciencesocieties.org/publications/jeq/ar
ticles/0/0/jeq2017.07.0300
Mapping at fine-scale
resolution across
variables- South Africa

13. • SOC as an indicator is now becoming mainstream in tools for decision
making – Decision making
– Needs to be understood in the context of management and land degradation
levels
• Current SHARED Dashboards
– Turkana County, Kenya http://landscapeportal.org/sharedApp/
– Laikipia County, Kenya
– Ziway woreda, Ethiopia http://gsl.icraf.cgiar.org/SairlaEthiopia/
– Mbarali, Tanzania
– Solwezi, Zambia (http://gsl.icraf.cgiar.org/SairlaZambia/)

14. Need for consistent landscape scale assessment
of ecosystem health and SOC dynamics
• Opportunities for this group and beyond
– Monitoring over time at the Climate Smart Villages (CCAFS),
Sentinel Landscapes (FTA), WLE
• Long-term experiments to answer key questions on storage
• Meta-analysis of our collective work
• Linking with the land restoration agenda
• Other ideas

15. Invest in climate-smart soil and
land health
http://hdl.handle.net/10568/89091
Better soil health can increase
#agricultural productivity.
Restoration activities build on-
farm #resilience & contribute to
#climate adaptation and
mitigation. Here's how: Brief 8
of 9:
https://cgspace.cgiar.org/handle/10
568/89091 @cgiarclimate
@CGIAR @IITA_CGIAR @ICRAF
@IFADnews #COP23
#AgAdvantage

16. Soil Restoration Efforts
SOIL RESTORATION FOR ACHIEVING THE 2063 AND 2030 AGENDAS IN
AFRICA: LINKING GLOBAL AMBITIONS TO LOCAL NEEDS
• http://www.worldagroforestry.org/event/soil-restoration-achieving-2063-
2030-agendas-africa-linking-global-ambitions-local-needs
• http://www.iisd.ca/soil/african-seminar/
• http://globalsoilweek.org/outcomes
Landscape portal
http://landscapeportal.org/
Land Restoration Project Website:
http://www.worldagroforestry.org/project/restoration-degraded-land-food-
security-and-poverty-reduction-east-africa-and-sahel-taking

17. Any Questions?

18. Thank you!
Leigh Ann Winowiecki - l.a.winowiecki@cgiar.org
Tor-Gunnar Vågen - t.vagen@cgiar.org