Analyzing resilience in dryland agro-ecosystems A case study of the Makanya catchment in Tanzania Elin Enfors Natural R

1. Analyzing resilience in dryland agro-ecosystems A case study of the Makanya catchment in Tanzania Elin Enfors Natural Resources Management Department of Systems Ecology Stockholm University

2. Based on manuscript by Enfors and Gordon (2006), submitted to World Development • Presenting a conceptual framework for analyzing resilience and conceptualizing alternative trajectories of development in smallholder farming systems • Applying this framework on the Makanya catchment in Tanzania A combination of qualitative and quantitative methods used: • Interviews with local farmers, extensionists and authorities about agro-ecological changes and underlying driving forces • aerial photo/satellite image interpretations of land cover change • analysis of rainfall dynamics

3. Why focus on dryland agro-ecosystems? • 250 million people in SSA: poverty, population growth, and malnourishment • Small-scale rainfed farming main income source, but productivity low • People depend on ecosystem services such as fodder for livestock,firewood and construction materials to cover basic needs • Climatic constraints and poor soils limit the agro-ecological productivity and make drylands inherently dynamic and vulnerable • Land degradation reduce both productivity and capacity to cope with change

4. The resilience concept Definition: the capacity of a social-ecological system to absorb changes, and to reorganize after and adapt to them, so that essential functions are not lost • Social-ecological systems can have multiple stability domains, characterized by different functions and feed-backs • Low resilience increases the probability for shifts between these • Most systems are robust over a range of conditions but respond strongly when key variables approached certain thresholds

5. The resilience concept applied The main function of agro-ecosystems is to generate food and other ecosystem services needed by the population Two alternative states envisioned for this system: one desirable where this capacity is up-held over time, one degraded where is is not We propose that the “soil water index” and the “ecosystem insurance capacity” are two of the key variables in this system

6. Soil water index - amount water available per capita for food production • Rainfall and run-on • Probability of actually receiving this due to dry-spells etc. • Soil properties affecting plant available water and plant productivity response to this water Ecosystem insurance capacity - capacity of the surrounding landscape to provide ecosystem services that could buffer yield variations • Availability of such ecosystem services (timber products, wild life etc.) • Capacity of the resource base generating these to recover after periods of stress

7. The conceptual framework

8. The Makanya catchment

10. The narratives on agro-ecological change and land cover change analysis largely support each other

11. Analysis of rain data High variability, no significant changes Significant increase, p=0.024

12. Summary • Over the past 50 years the landscape in the catchment has undergone considerable changes: reduction in bush land and expansion of farm land, loss of ecosystem services other than food • At the same time the frequency of dry-spells has increased significantly and the population in Same district is estimated to have increased with more than 200 %

13. Applying the resilience framework on this case a) Population increase outgrows management of farming land -> decline in SWI, accelerated by increasing dry-spell frequency b) Low SWI -> increased dependency on ecosystem insurance capacity. Institutions for access and control of NR collapse -> the system moves to the degraded state c) Today: a system where production of food and other ecosystem services is not upheld over time

14. Potential for reversing a negative trend A window of opportunity for change seems to be opening: • Awareness of the problem • Practical solutions available - soil and water system innovations: water harvesting, conservation tillage etc. • Policy changes the last 10 years have made local initiatives for NRM possible • New local institutions are being built

15. Thanks for listening!