1. Synergies and trade-offs amongst
multiple functions of trees in agricultural
landscapes in Sub-Saharan Africa
S Kuyah, I Öborn, A Malmer, E Barrios,
A S Dahlin, M Jonsson, C Muthuri, S Namirembe,
J Nyaga, Y Nyberg, F L. Sinclair

2. Outline
• Introduction and research question
• Literature review and synthesis
• Assessing ecosystem services
provided by trees
• Benefits and tradeoffs between
ecosystem services
• Lessons learned and knowledge gaps

3. Trees in agricultural landscapes
provide ecosystem services
Ecosystem service categories (MA, 2005);
• provisioning (e.g. food, fodder),
• regulating (e.g. microclimate),
• supporting (e.g. nutrient cycling),
• cultural (e.g. shade, aesthetic).
jackfruit
Shaded tea Calliandra hedges

4. Multi-functional landscapes in sub-
Saharan Africa
• Sub-Saharan Africa (SSA) is home to ≈910 million
people (The World Bank, 2012)
• About 63% of this population dwell in rural, and rely
on ecosystem services
• Multifunctional landscapes offer a range of multiple
ecosystem services relevant to SSA

5. Overall question
• What is the present scientific evidence base that
integration of trees on farms and in agricultural
landscapes will contribute to enhanced agricultural
productivity, resource utilization and livelihoods for
smallholder farmers?
• Are all these benefits indeed co-benefits or are there
trade-offs, and are there empirical studies available
for relevant scales and contexts?

6. Methodology
Structured literature search
Relevant studies
• Peer reviewed journals
• Agricultural landscapes within
sub-Saharan Africa
Information sources
• Web of science, Scopus, Science
direct
Search strings combining variants
of ecosystem services produced by
trees
Bias minimised by multiple
reviewers
Synthesis
Number of studies determined
by vote-count
Positive (+) or negative (-)
impact of trees captured where
significant
Stratification based on
• Ecosystem categories
• Agro-ecological zones
• Field, farm and landscape

7. Ecosystem services provided by trees
Results
• A total of 409 studies at 202
sites in 23 countries
• Relevant to 4 agro-ecological
zones.
• The ecosystem services are
grouped into four major
classes
• The ecosystem services are
produced, utilized and
assessed at different scales

8. Ecosystem services provided by trees
1%
46%
27%
25%
Arid Semi-arid
Sub-humid Humid
Results
• A total of 409 studies at 202
sites in 23 countries
• Relevant to 4 agro-ecological
zones.
• The ecosystem services are
grouped into four major
classes
• The ecosystem services are
produced, utilized and
assessed at different scales

9. Ecosystem services provided by trees
33.3
28.4
38.1
0.2
Provisioning Regulating
Supporting Cultural
Results
• A total of 409 studies at 202
sites in 23 countries
• Relevant to 4 agro-ecological
zones.
• The ecosystem services are
grouped into four major
classes
• The ecosystem services are
produced, utilized and
assessed at different scales

10. Ecosystem services provided by trees
Results
• A total of 409 studies at 202
sites in 23 countries
• Relevant to 4 agro-ecological
zones.
• The ecosystem services are
grouped into four major
classes
• The ecosystem services are
produced, utilized and
assessed at different scales
63
23
14
Field Farm Landscape

11. Benefits and Tradeoffs
• Ecosystem services are interlinked, and they interact
• Management practices alter a range of ecosystem
services positively, yielding benefits or negatively
resulting in tradeoffs
Results
Enclosures in grazing areas Guava tree planted at river bank

12. Benefits and Tradeoffs
• Ecosystem services are interlinked, and they interact
• Management practices alter a range of ecosystem
services positively, yielding benefits or negatively,
resulting in tradeoffs
Results

13. Benefits and Tradeoffs
More value is placed in provisioning services
Results
0
10
20
30
40
Food
Fodder
Nutrient
cycling
Soil fertility
Carbon
storage
Microclimate
Benefits

14. Benefits and Tradeoffs
More value is placed in provisioning services
Results
0
20
40
60
80
Food
Fodder
Nutrient
cycling
Soil fertility
Carbon
storage
Microclimate
Tradeoffs
0
10
20
30
40
Food
Fodder
Nutrient
cycling
Soil fertility
Carbon
storage
Microclimate
Benefits

15. Conclusion
• Trees play a crucial role in sustaining productivity of
agricultural systems, but there are also tradeoffs, in
particular with food crops
• Ecosystem services are often studied at lower (field)
scale than where they are produced and utilized
• Many ecosystem services from trees are known to be
produced in forest areas, but few studies on farms

16. Acknowledgement
The study was supported by funds
allocated to the Swedish University of
Agricultural Sciences by the Swedish
Ministry of Foreign Affairs as part of its
special effort on global food security.