Socio-ecological resilience to soil erosion driven by extreme climatic events: past, present and future challenges in East Africa.

With growing land-use pressures and consequent severe soil erosion, many East African socio-ecological systems are at a tipping point. Continued and accelerating soil erosion presents a credible threat to community and ecological resilience to future climate change shocks.

Soil erosion and downstream siltation problems challenge water, food and energy security, with growing threat from climate change. Even under 'normal' climatic conditions, soil erosion reduces water and nutrient retention, biodiversity and plant primary productivity on agricultural land putting stress on food production, notwithstanding ecosystem and water resource/power generation impacts downstream. This undermines the resilience of communities that depend on soil and water resources, and shocks are often amplified by physical and socio-cultural positive feedback mechanisms. Shocks can, however, lead to a learning experience that propels a system to a qualitatively different pathway. This can support greater-than-previous levels of resilience (sometimes termed 'bounce back'). Co-production of sustainable land management practises will help enable agrarian and pastoral communities to (1) withstand shock of future extreme hydro-climatic events and (2) recover from prior environmental impacts to a resilience level beyond the prior state through restoration/enhancement of degraded landscapes.

Facilitating a step change in land management practice to reduce complex soil erosion impacts is a fundamental target within the UN Sustainable Development Goals, a challenge that requires an interdisciplinary approach. To bring about urgently needed change in land management practice behaviour, evidence is required to demonstrate how social resilience is intrinsically linked to landscape/ecological resilience through the coupled co-evolution of natural resource systems and dependent rural communities.

The East African Rift System (EARS) region has the highest catchment sediment yields of sub-Saharan Africa linked in part to topography and rainfall but also to recent and historic land conversion to agriculture and, in particular, increasing livestock numbers on grasslands. Extreme drought and rainfall events, which are already a characteristic feature of tropical climatology (e.g., linked to ENSO), are widely accepted to increase in magnitude and/or frequency with global climate change. There is a real risk that, in the absence of community-owned soil management programmes, recent land use change will amplify hydro-climatic and consequent societal impacts. This is exacerbated by socio-cultural lock-ins such as power and esteem gained by owning livestock, putting pressure on fragile ecosystems and ecosystem services, with repercussions for economic and human health.

Experts in soil erosion and land degradation problem identification are not necessarily experts in socio-economic and socio-cultural solutions. To tackle this challenge, we propose an interdisciplinary approach to designing sustainable land management practices that would enable rural communities affected by soil erosion to overcome post-erosion shocks and achieve a higher level of resilience than previously. Through novel integration of environmental science, arts and humanities and social science evidence, this project will map out potential behavioural changes and how these can be embedded in the design and implementation of soil conservation and restoration strategies. The interdisciplinary approach in this foundation-building programme will develop knowledge of complex interlinkages between soil degradation, climate change, and community resilience in the EARS region, as well as to explore pathways to possible solutions. Interdisciplinary evidence of the problem will be explored against complex socio-cultural community concerns and needs, and potential solutions will be considered with stakeholder groups to identify and underpin future behavioural change in land management.

The Pathways to Impact strategy encompasses four key stakeholder groups: (1) Policy makers and land managers/farmers in the host country, (2) organisations with regional (East Africa) engagement in soil conservation policy development, (3) inter-governmental bodies concerned with soil conservation policy and (4) UK citizens and taxpayers. Existing strong and well-established networks in Tanzania will underpin this impact plan which is integrated with the work programme.

(1) Local land managers and policymakers: (a) Mviwata smallholders farmer organisation, a farmers union in the Arusha region, who want to improve farmer rights and communication of issues affecting their livelihoods; (b) Ujamaa-CRT pastoralists group, which exists to strengthen livelihoods and social justice for pastoralist, hunter-gatherer and agro-pastoralist communities through security over land and natural resources, and sustainable community-based natural resource management; (c) The Tanzanian Internal Drainage Basin Water Board (IDBWB) who manage waterways, supply and irrigation as well as maintaining local meteorological data records and (d) The Tanzanian National Parks Authority (TANAPA) who have jurisdiction over larger areas of land in the Manyara Basin. They focus on biodiversity conservation in the National park itself but also do conservation outside the park boundaries such as building coffer dams etc to trap eroded soil. Links to local landowners will be facilitated directly by NM-AIST scientists who work in the region actively on agronomy research programmes. Key activities include You Tube 'awareness raising' video for stakeholder communities, a bottom-up approach of training locals in best practice will be strengthened by the current work of NM-AIST in this area and the activities of the final stakeholder workshop.

(2) Organisations with regional (East Africa) reach in soil conservation policy development: this project will partner with the International Water Management Institute (IWMI) Nile Basin and East Africa Office based in Addis Ababa in Ethiopia, a non-profit research-to policy and development organization, with mandate on the sustainable use of water and land resources for agricultural development. Their mission is to provide evidence-based solutions to sustainably manage water and land resources for food security, people's livelihoods and the environment. They will facilitate stakeholder workshop activities and dissemination of project findings to regional organisations with responsibility for land management. Knowledge will be applied and disseminated in other regions where IWMI is active such as the Volta basin, Niger Delta, Mekong Delta amongst others.

(3) The project is also relevant to the UN FAO Subregional Office for Eastern Africa mission to contribute to enhancement of an enabling environment for economic growth and food security through sustainable agriculture and rural development in Eastern Africa. Impact via this route will be facilitated by partnership with UN FAO/IAEA through Joint UN FAO/IAEA coordinated research programmes and training provided within the regional Africa-based project Supporting Innovative Conservation Agriculture Practices to Combat Land Degradation and Enhance Soil Productivity for Improved Food Security (RAF5063). The PI will disseminate project plans and findings at scheduled training programmes through a new Coordinated Research Programme Nuclear Techniques for a Better Understanding of the Impact of Climate Change on Soil Erosion in Upland Agro-ecosystems. They also provide links to key UNESCO groups which will be developed in a subsequent wider-ranging programme.

(4) The UK public is an important stakeholder in the research itself as funding providers and wider benefits will be achieved through science communication initiatives (e.g. through an artistic media event and workshops with an 'artist/photographer in residence') and schools liaison.