1. SMALLHOLDERS’ AGRICULTURE AT THE TROPICAL FOREST MARGIN IN
CAMEROON: OPPORTUNITIES FOR A LANDSCPE APPROACH TO PROMOTE
AGROFORESTRY
Valentina Robiglio, 29/11/2011 WORLD AGROFORESTRY
CENTRE, Nairobi

2. BIO-PRESENTATION
v.robiglio@cgiar.org
Forest landscape ecologist at IITA
partner in the ASB platform
Research subject: analysis of land use
systems at the humid
tropical forest margin. Implications for
livelihoods, carbon sequestration and
biodiversity.
Key words: smallholder
farmers, shifting cultivation, land use
trajectories, deforestation and forest
degradation, tree based mitigation
(REDD+/REALU) and adaptation
strategies

3. CAMEROON
Population: 19.5 M, 42% rural, urbanization
Dense tropical forest : 3.4%, variation across regions 7.5 p/Km2 Est, 12.5
PFD 12M ha protected 4.5M p/Km2 South;
production 7.5 Economy: GDP 44 billions $, agriculture 20% GDP –
NPFD 5M ha liable to conversion labor force 70%;
Export: oil, lumber and cocoa
Deforestation rate: 1.1%
Dense humid forest: 16.5 M ha
Major driver of deforestation
small-scale agriculture
REDD+

4. THE LAND USE MOSAIC AT THE FOREST MARGIN
Fallow Units and secondary forests  4 M ha
Annual crops  900 t ha Cocoa Agro-forests  500 t ha

5. DEFORESTATION
In much of CA and WA the expansion of agriculture by small-holder farmers is
a leading driver of deforestation;
Nutrients in the plant biomass are mined by agricultural households
employing slash and burn;
The same households depend on stock of wild food, fuelwood, and traditional
medicines which are produced by the forest they cut down and burn in their
agricultural practices;
Fallows and agroforests provide environmental services such as biodiversity
conservation and carbon stock =>mitigation of deforestation.

6. LANDSCAPE CONCEPT AND LANDSCAPE APPROACH
Production
Ecosystem services Biodiversity
Institutions
Carbon sink and sequestration
Livelihoods strategies
policy System resilience
Landscapes: spatially heterogeneous geographic areas characterized by diverse
interacting patches or ecosystems
Landscape approach is necessary to deal at the same time with
production, biodiversity, ecosystem services and functions, livelihoods
strategies, policy and institutions across scales.
That approach is particularly valuable to create an understanding in the complex
(competing) interrelationships between resource use and users across scales.

7. BEYOND THE UNDERSTANDING OF LAND USE /LAND COVER CHANGE
What are the implications of LULC on local
and global environmental services
provided by landscapes?
Are LULC changes indicator of agricultural
change? (e.g. a change in the social asset,
or technology…)
What are the entry points for AFS once
adopting a landscape approach?
Comparison of HH data for
1996-2011 in AWAE

8. impact of combined agricultural expansion/deforestation and intensification processes on the
potential for biodiversity conservation in shifting cultivation landscapes
What are the current trends in the agricultural mosaics and how do they affect forest species
regeneration capacity and conservation potential of the mosaics?
1) What factors do control species regeneration (fallows)?
2) What are the factors that shape LULC at the local scale and how do they operate?
Robiglio V., Sinclair F.L. (2011). Maintaining the Conservation Value of Shifting
Cultivation Landscapes Requires Spatially Explicit Interventions. Environmental
Management . 48(2): 289-306.

9. impact of combined agricultural expansion/deforestation and intensification processes on the
landscape structure
potential for biodiversity conservation in shifting cultivation landscapes
Shifting cultivation landscapes are complex fragmented landscapes: Complexity
results from the dynamics within the non-forest agricultural matrix and from the
linked process of forest loss and recovery in fallows.
PLOT LEVEL TRAJECTORIES
LANDSCAPE LEVEL
OUTCOME

10. impact of combined agricultural expansion/deforestation and intensification processes on the
potential for biodiversity conservation in shifting cultivation landscapes
•Focus Group RRA
•Participatory GIS mapping to define
territory/landscape scale on the base of
land resources management;
•RS fine grained monitoring of
transition and modification of LC
classes;
•Analysis of forest fragmentation and
agricultural expansion (FRAGSTATS)
Nkometou
Core Area Herbaceous land Shrubland Grassland herbaceous
100
1951 2001 1951 2001 1951 2001 80
60
Nkometou 40
%of class’ land 43.6 65.7 58.3 49.1 68.9 67.8 20
Core areas per patch 1.4 1.8 1.5 1.4 1.2 1.3
0
Mean core area 1.4 12.7 3.7 1.9 5.8 9.7
1951 2001 1951 2001 1951 2001
Median core area 0.6 1.1 1.1 0.9 2.3 2.2
Core area range 7.1 449.5 42.0 25.8 45.0 44.8 shb hb gr_hb
hb shb frF_agr fr_mlF mlf dhf gr_hb gr

11. impact of combined agricultural expansion/deforestation and intensification processes on the
potential for biodiversity conservation in shifting cultivation landscapes
Plot level
trees species richness and diversity
assessment per land use type
factors affecting the pattern of
abundance of woody species:
-Plot level factors : the land
use, weeds layer, the density of un-
felled trees, age
-Landscape factors: mature
vegetation, forest , matrix.
1. test of the influence of plot
and landscape sets using RDA
2. significant sets arranged in a
hierarchy, on the basis of a
variance partitioning
procedure.

12. impact of combined agricultural expansion/deforestation and intensification processes on the
potential for biodiversity conservation in shifting cultivation landscapes
Results
Species regeneration:
1) The type of agricultural matrix in which the fallows are embedded, the degree of
adjacency to mature vegetation and the distance from the forest have the highest impact
on forest species distribution in the regenerating fallows.
Land Use / Land Cover change:
1) Agricultural patches are expanding and merging;
2) Remnant forest patches are shrinking and increasingly isolated;
3) Within the agricultural matrix the proportion cropped at any time is increasing, as well as
the frequency and size of short fallow patches;
4) Fallow plots are increasingly scattered throughout the agricultural matrix and isolated from
one another and the remaining forest => loss of fallow functions and degradation of the
agricultural matrix

13. impact of combined agricultural expansion/deforestation and intensification processes on the
potential for biodiversity conservation in shifting cultivation landscapes
Implications:
Methodological:
1. Analytical frameworks of forest fragmentation and conservation at the tropical
forest margin should integrate the processes that control secondary forest recovery
within the agricultural matrix: the intensity, persistency and spatial pattern of the
agricultural disturbances.
Landscape management:
1. Non-forest matrix provides required conditions in the absence of forest;
2. With the loss of fallow functions, scattered trees, live fences, multistrata
cocoa, home gardens and small degraded forest spots that farmers
maintain, become the foci of conservation and dispersal of forest species;
3. Spatial distribution matters!

14. factors influencing farmers land use decision making in the villages functional territories
Robiglio V., Mala W.A. and Diaw M.C. (2003) Mapping landscapes: Integrating
GIS and social science methods to model human-nature relationships in
Southern Cameroon. Small-Scale Forestry Volume 2, Number 2, 171-184.

15. What are the implications of landscape change on the local and global
environmental services?
•12 villages HH surveys + Focus groups for
LUC Drivers, Resources Management,
income, landholdings
•6 villages for carbon and trees biodiversity
assessment , GPS-LU mosaic mapping, land
use trajectories and profitability analysis
•LULC analysis over 2001-2007 based on
Landsat and Aster img.

16. What are the implications of landscape change on the local and global
environmental services?
data collection
• 173 Plots
• LUTs:
Degraded forest
Logged forest
Secondary forest
Fallows
Cocoa farms
Trees dbh > 5cm, measured and
identified
+understory, litter, dead trees
• Allometric equation adopted:
AGB = ρ * EXP {-1.499 + [2.148 * LN(DBH)] + [0.207 * LN(DBH)] 2 – [0.0281 *
LN(DBH)] 3} Chave et al. (2005)
AGB = aboveground biomass in kg/tree ρ = wood density g/cm3
EXP = ―e‖ to the power of DBH = diameter at breast height
in cm

17. What are the implications of landscape change on the local and global
environmental services?
preliminary results
1. LULC 2001/2007 :
Clusters of local landscape changes allow
identifying typical landscapes of shifting
cultivation, settled areas with more stable
agriculture, and areas with net
deforestation, how these are distributed in
space and how they relate to pattern of
identified drivers.
Within a dynamic landscape with high
percentages of LU changes, the aggregated
proportion of forest is stable but there are
contrasting local dynamics ;

18. What are the implications of landscape change on the local and global
environmental services?
preliminary results
2. Land Use Mosaic:
Perennial crops Slash and Burn systems
Traditional Shaded Cocoa Oil Palm-small scale Forest fields (Essep ) M ixed Foodcrop M onoculture Foodcrops
% of land 9.70% 4.30% 8.20% 3.40% 0.10%
S (ha) 0.6 3.4 0.6 0.13 0.19
*Data for 1 site Fallow land is the main component of the
land use mosaic

19. What are the implications of landscape change on the local and global
environmental services?
Land Use System Change Carbon stock distribution
General trends of Change reported by the farmers in sites with good market
acces:
1) Increase of number of fields by HH, in particular under short intercrop
systems : introduction of mono-cultural crops
2) Increase of average fields surface in particular for forest farms
3) Decrease of remnant trees left during field preparation both for mixed food
crops and in cocoa farms
DEGRADATION of the RURAL MOSAIC

20. What are the implications of landscape change on the local and global
environmental services?
preliminary results
3. Carbon and species diversity indicators
Carbon/tree species diversity correlate significantly across the land use types
considered (R, Pearson 0.748; SW, Pearson 0.663, p<0.001)
Carbon /tree species diversity
correlate for non- pioneer and
late/shade bearer species in fallow
intercrop degraded forest
(R, Pearson 0.64, p<0.01).
late/shade bearer species show the
clearest pattern with C stock both
for fallows and degraded forest

21. What are the entry points for AFS? On –farm timber production
a flourishing domestic timber sector…
3.0
Millions m3
2.0
1.0
Robiglio, V. et al. 2011.From farmers
to loggers: understanding the role of
0.0 the rural land for timber production
2000 2005 2010
in Cameroon. Submitted to a special
Official production SSL informal production issue of Small Scale Forestry .
Robiglio, V. et al. ASB PolicyBrief23
On-farm timber production
Once SSL production is included the overall for emission reduction with
value of national timber production doubles! sustainable benefits at the tropical
forest margins.
21

22. What are the entry points for AFS? On –farm timber production
…targets a handful of species harvested …
Five species made about 75% of
total sales in Yaounde.
Ayous is the most largely
commercialised
Important commercial species
are harvested more in the
NPFD
Source: Cerutti and Lescuyer
2010 22

23. What are the entry points for AFS? On –farm timber production
…in the agricultural land use units
23

24. What are the entry points for AFS? On –farm timber production
What are on-farm trees in the rural mosaic?
Farmers traditionally maintained selected
forest species on their farms
1. increase crop productivity (e.g.
enhancement of soil fertility, of nutrient
cycling, management of light and
moisture, protection from wind);
2. provide valuable products
(food, medicines, construction timber, fuel
wood etc.) for household consumption and
income diversification.
!! On-farm trees in Cameroon are not managed by farmers for timber
production.
!! SSL benefits of a stock of trees that were preserved by farmers for reasons
other than timber production

25. What are the entry points for AFS? On –farm timber production
Towards an assessment of the opportunity to develop management options for the
on-farm timber stock
Are there significant variations in tree species
distribution in the different land use systems?
What are the factors influencing trees species
distribution?
How will the evolution of agricultural land use systems
affect future timber production?
Can timber production from farmland become a
livelihood option for smallholders?
25

26. What are the entry points for AFS? On –farm timber production
Results: Farmland timber Stock and species
About 49 over 51 commercial
species inventoried. The most
abundant were the Pioneers and
Non Pioneer Light Demanding
Species;
Larger volumes and higher
density values were found in the
Nkolabang, intensively cultivated, short rotations are dominant, high population
fallow units (medium and old) pressure
and for secondary species,
Trees density varied across sites;
Within sites trees density varied
across Land Use Units;
ANOVA of average density per LUT
was significant only for one
species in one site (Iroko, F=2.79,
Mevo Mevo, medium and long fallow rotations are dominant, low population pressure
p=0.026). 26

27. What are the entry points for AFS? On –farm timber production
Other results
P and NPLD species regenerate and grow in fallow
based and permanent tree crop systems
Density depends on the type of LUT, the length of the
fallow rotation and on the species
There is a high potential to promote secondary species
in particular in the fallow units
Agricultural expansion and intensification coupled to
logging is rapidly reducing the availability of farmland
trees >> need for intervention to avoid timber shortage

28. What are the entry points for AFS? On –farm timber production
Analysis of barriers
Tenure and use right restriction
In particular the prohibition to sell, that is the impossibility of fully benefit of their
use right on trees growing on their customarily owned land is perceived as a barrier
to get involved in planting and better managing timber trees.
Tenure insecurity becomes an issue in relation to the time needed by the trees to
grow and become exploitable.
Low profitability
Farmers feel they have a low power of negotiation and get low returns for a valuable
product. Not aware of the economical value of the timber they consider the low price
justified by the lack of investment in production.
Technical restrictions: lack of management skills and information
Farmers’ knowledge about managing timber trees regeneration and growth is limited
to very basic techniques and fully depend on natural regeneration.

29. What are the entry points for AFS? On –farm timber production
Opportunities and the way forwards
There is potential for indigenous timber species to be associated with smallholder
crop production.
Natural regeneration should be integrated by domestication and planting with the
development of related technical protocols.
Farmers’ knowledge about tree management and tree properties should be
complemented with technical knowledge on crop-trees complementation.
Adapted management units should be identified and inventory and monitoring
systems developed.
The system has to be integrated in the design of agricultural intensification options
considering spatial distribution.
Main barriers such as lack of rights and delayed benefits to farmers should be
addressed with benefit sharing mechanisms that favor short term payback and
market information systems on domestic and international timber prices, to
increase farmers’ awareness of timber value.
In the long term, reforms to reinforce tree ownership by farmers, and control over
timber resources.

30. THANK YOU VERY MUCH FOR YOUR ATTENTION !!!! MERCI!!!! GRAZIE!!!
ASANTE SANA!!!!

31. LULC: DEGRADATION AND AGRICULTURAL INTENSIFICATION
Complex mosaics evolve from tree-rich to tree-poor systems
vertical: cocoa agroforests
horizontal: shortening of fallows and expansion of homogeneous agricultural
matrices;
Fine grained mosaic dynamics are difficult to monitor... and not considered in
general debate about tropical deforestation / degradation and land use
change;

32. trees species richness and diversity assessment per land use type
factors affecting the pattern of abundance of woody species:
1. test of the influence of plot and landscape sets using RDA
2. significant sets arranged in a hierarchy, on the basis of a
variance partitioning procedure

33. preliminary results
3. Carbon and species diversity indicators
• Mature Cocoa farms and Long fallow intercrop stock a high amount
of carbon
• Cocoa and Long fallow intercrop present high tree species diversity
values
Land USE Carbon T/ha Diversity
cocoa1 55.07 0.23
cocoa2 99.21 0.37
cocoa3 93.63 0.37
cocoa4 115.94 0.36
YF 34.43 0.14
MF 41.57 0.18
OF 101.47 0.41
SF 130.81 0.41
LF 152.91 0.54
DF 204.81 0.57

34. ANY ROLE for REDD+ in small-holder farmers
context?
Depends on what is eligible
and on the adopted national
forest definition.
CARBON ENHANCEMENT (RESTORATION)
and AVOIDED DEFORESTATION in identified
priority areas
Cameroon National forest definition "Forest is a tract of
land with a minimal surface of 0.1 hectare, with tree canopy
cover of more than 30% (or with an equivalent stand
density). The trees or woody vegetation should be able to
reach a minimum height of 5 m.”

35. methodological challenges for the next steps
• Coupled biodiversity inventory and carbon
stock measurement
• Uncertainty in carbon estimates due to lack of
suitable allometric equations
• What biodiversity and which indicator or
combination of indicators are suitable?
• At what spatial scale?