Desertification and land degradation: origins, processes and solutions

Table of Contents

1. Authors and acknowledgements
2. Introduction
   1. Aims
   2. Definitions and key concepts
   3. Synthesis of previous and ongoing projects
   4. Key issues and outline
3. Evolution of desertification in the Mediterranean
   1. Climatic fluctuation
   2. Human influence
4. Primary drivers of desertification
   1. Biophysical and socio-economic causes
   2. Pathways of desertification
   3. Driving forces in the Mediterranean
   4. Synthesis of causes for DESIRE hotspots
   5. Conclusions
5. Processes and consequences of desertification in the Mediterranean
   1. Socio-economic and political factors
   2. Biophysical processes
   3. Conclusions
6. Indicators: monitoring desertification
   1. History of monitoring
   2. Indicators
   3. Monitoring and mapping techniques
   4. Concluding remarks
7. Modelling desertification
   1. Definition of modelling
   2. Model types
   3. Biophysical modelling
   4. Socio-economic and participatory modelling
   5. Gaps and progression in modelling
8. Solutions
   1. Biophysical solutions
   2. Political and socio-economic solutions
9. References

Solutions

Next to the many projects and research on the processes, causes and extent of desertification, many solutions to desertification related problems (e.g. land degradation) have been proposed. As desertification problems are complex (e.g. Thomas, 1997), so are solutions (WOCAT, 2007). Reynolds et al. (2007) defined five lessons learned about sustainable development in the drylands, all of which show the complexity of the problem: (1) Integrated approaches are needed; (2) Short term measures cannot solve slowly evolving conditions; (3) Dryland systems have nonlinear processes; (4) Cross-scale interactions must be anticipated; and (5) Greater value must be placed on local environmental knowledge.

Solutions to desertification or land degradation in drylands have been applied since ancient times. Examples include terraces, irrigation schemes, water harvesting etc. The first in particular, though effective in reducing erosion, need constant maintenance. Solutions and problems can be interrelated, e.g. grazing by animals can help reduce the risk for forest fire (Conacher and Sala, 1998) but at the same time may lead to overgrazing problems if not controlled properly. In this chapter, some solutions and basic principles are given, but these should be evaluated locally in their physical and socio-economic context. Even where solutions and remedial actions have been successful, they may not be simply transferable from one location to another, due to differences in the physical environment but also because cultural differences may make the components of the necessary actions unacceptable or difficult to apply (Thomas, 1997). For an extensive analysis of soil and water conservation worldwide (i.e. not restricted to desertification or the Mediterranean), see WOCAT (2007).

There are no simple 'silver bullet' solutions to the complex problems of land degradation. It is therefore important to understand the ecological, social and economic causes of, and processes behind, degradation, to analyse what works and why, and how to modify and adapt particular technologies and approaches to locally specific circumstances and opportunities. Solutions need to be flexible and responsive to changing complex ecological and socio-economic environments. An urgent and specific area for further investigations and research is quantification and valuation of the ecological, social and economic impacts of SWC, both on-site and offsite, including the development of methods for the valuation of ecosystem services. SWC research should seek to incorporate land users, scientists from different disciplines and decision-makers. A continuous feedback mechanism is needed to ensure active participation of these stakeholders.

Although obviously they should be implemented in a combined way, a division is made here between several types of biophysical solutions and political and socio-economic types of solutions. However, it is recognised that any biophysical solution needs a social background of acceptance before it will be effectively adopted and implemented.