The challenge of HIV/AIDS: Where does agroforestry fit in? - World ...

48World Agroforestry into the Futurelimits under some conditions. Izac andSwift (1994) argued, for instance, that asustainable agricultural landscape mightnecessitate a balance between areas of exploitationof resources and areas in whichthey are permitted to accrue. This relates tothe third challenge.Challenge 3: What are the tradeoffsbetween the storage of organicmatter in the soil (to counter theclimate change effects of increasedgaseous emissions) and its use todrive nutrient cycling, crop productionand other ecosystem services?Socio-biophysical interactions are apparentat all scales, but primarily at the landscapescale where the impacts of decisionsmade by different stakeholders across arange of scales interact (Figure 1). The twoSystemwide Programmes managed by theCentre (the African Highlands Initiativeand the Alternatives to Slash and BurnProgramme) have been at the forefront indeveloping approaches and methods forassessing the interactions between environmental,economic, social and politicalfactors in natural resource management(Stroud 2001; Stroud and Khandelwal2003; Palm et al. 2005). The proposal forthe Challenge Programme for sub-SaharanAfrica drew upon these lessons by picturingan interactive chain of cause and effectin land degradation and unsustainable agriculture.This chain links the degradation ofnatural resources to failures in market accessand performance, thence to inappropriatepathways of system intensification,and finally to inadequate policies (FARA2003). The analysis provided in the ChallengeProgramme documentation serves inparticular to direct attention to the ‘interactions’between these sectors of the researchenterprise as well as to the issues withineach of them (the fourth challenge).Challenge 4: What are the keyquestions arising from interactions inthe chain linking resource management–systemintensification–marketaccess–policy?Integrating across scalesThe rules governing resource management,and the institutions making them, changeas scales change. For example, rules (orthe lack of them) made from the nationalperspective can strongly influence localbehaviour and may result in significantfeedback effects (Figure 1). This complexityis compounded by changes in dominanceof the factors determining natural resourcedynamics at different scales (e.g. van Noordwijket al. 2004 with respect to hydrologicalflows and Swift et al. 2004 in relation tothe significance of biodiversity). The type ofmanagement (communal or individual, governmentor private) apparent within the landuse types and the gender and wealth dimensionis also important. Thus, a range ofsocial parameters enters the equation. Theseissues have been analysed by the CGIARTaskforce on Integrated Natural ResourceManagement and the reports and papersemanating from that group (e.g. Campbelland Sayer 2003; Sayer and Campbell 2001)together with the framework developed byIzac and Sanchez (2001) offer some of thebest analyses of the methods, approaches,successes, opportunities and challenges thatface a scientific community committed toissues of ‘Land and People’.In a recent study of watershed managementissues that cut across scales and social perspectivesin the East African Highlands (reportedby German 2003 and Stroud 2003),five main categories were identified:1. Issues involving the management ofcommon property resources which compromiseeither the quantity or quality ofthese resources.2. Issues involving limited access andinequitable distribution of resources(absolute and relative shortages).3. Trans-boundary effects between neighbouringfarms and villages.4. Areas in which collective action couldsignificantly enhance farm productivity,either through increased access toproductive resources (natural resources,labour, capital) or through cooperationto conserve resources that are underthreat (biodiversity, local knowledge).5. Areas in which collective action iscurrently needed to enhance incomeor livelihood more broadly (publicworks, governance of existing resources,marketing).Of equal interest to variation across spatialscale is the influence of change over differentscales in time. Crowley and Carter(2000) provided a detailed and perceptiveanalysis of the historical factors that haveinfluenced the current state of natural resourcesand agricultural practice in westernKenya. Such analysis influences an importantdebate in natural resource managementresearch. It is often asserted that the characteristicsof the natural resource base andits management are highly site-specific, anobservation largely derived from the hugebiophysical variation that is commonly seenbetween neighbouring fields with respectto soil fertility status and other biologicalproperties. These observable differencesmay derive, in some cases, from variationsin underlying materials, but are more frequentlya product of the history of humanmanagement of the natural resources ofthe plots, farms and regions concerned in