Agroforestry Systems in Space and Time

1
Agroforestry Systems in Space and Time

• Modelling Household Decision-making by
  Subsistence Farmers in Cameroon

2
Shifting Cultivation

• A form of semi-subsistence agriculture
• An agroforestry system
• Forest resources used for
• Agricultural production
• Non-timber forest products
• A dynamic spatial phenomenon
• Multiple patches in various locations
• Cleared for temporary cultivation

3
Shifting Cultivation

• Issues
• Sustainability of agriculture-fallow-forest
  mosaic
• Sustainability of household livelihoods
• Ex ante assessment of alternatives

4
Dynamics of Shifting Cultivation
Characterized by temporary forest clearing
Each patch is a dynamic system
5
Spatial Aspects of Shifting Cultivation
The choice of patches for active cultivation is a
spatial process
A dynamically evolving spatial mosaic
6
Resources for Shifting Cultivation

• Constrained by household resources
• subsistence requirements
• labour resources

7
Forest Margins Benchmark

• Population density
• Forest availability
• Market access

8
The Mixed Food Crop Field
9
Field Fallow Forest Succession
Forest melon field (1 year)
Fulu (0 years)
Primary forest (gt20 years)
Mixed food crop field(3 years)
Secondary forest (11-20 years)
Young fallow (1-4 years)
Forest fallow (5-10 years)
10
Determining the Preferred Patch

• Two components to measure
• Characteristics of patches available to household
• Importance or value of these characteristics
• Household-specific socioeconomic circumstances
• Generate patch-specific scores
• Household chooses the best patches for
  cultivation in any one year

11
Preference Elicitation

• Importance of farmers decision criteria
  regarding
• Field location
• Field size
• Crop mixture
• Preferred type or age of fallow
• Fallow, forest-fallow forest
• Stated preferences

12
Preference Elicitation

• Relative suitability of principle types of
  available land
• Fallow, forest-fallow forest
• Availability of principle types of land
• Size of the households choice set
• Actual types of land chosen
• Revealed preferences

13
Survey Methodology

• Household survey
• Semi-structured interview
• Modified version of an indigenous board game
• Used in East Africa by Franzel for farmer
  evaluations of AF species
• Quantified importance of decision criteria

14
Field Location
Mixed food crop field, season A
15
Preferred Fallow Age Lower Limit
16
Preferred Fallow Age Upper Limit
17
Suitability of Fallow Types
18
Availability of Fallow Types

• Bounds of choice set

19
Actual Choice of Fallow

• Revealed preferences

20
Conclusions

• Factors affecting decision-making
• Economic variables
• Non-economic variables
• Preferred fallow age and suitability
• Correspond closely

21
Conclusions

• Long-term viability of shifting cultivation
• Some households lack sufficiently old fallows to
  ensure maintenance of yields in the long run
• Lack of resources may not constrain choices
• Individual preferences may mean that choices are
  well within the bounds of the choice set

22
Some implications

• Preferences are important
• Understand preferences to understand behaviour
• Preferences dont fit our mental models well
• i.e., optimal rotation, fertility
• The decision process is much more complex

23
Some implications

• Efforts to change preferences can have a
  considerable impact on household livelihoods and
  the landscape
• Price changes can have a real impact on outcomes
• Outcomes also depend on initial conditions

24
Acknowledgements

• Support for this research has been provided by
• International Institute of Tropical Agriculture
  and the Alternatives to Slash and Burn program
• Social Sciences and Humanities Research Council
  of Canada
• Cornell University