IAP-25-134

The role of tree-based landscapes in improving food security and nutrition across West Africa

Despite vast expansion of agricultural land and significant gains in crop yields in recent decades, more than 800 million people remain undernourished and two billion suffer from micronutrient deficiencies worldwide (FAO et al., 2025). At the same time, the agri-food sector is responsible for a third of greenhouse gas emissions and is the leading driver of deforestation and thus, biodiversity loss at the global scale (Clark et al., 2019). While achieving food security and improving people’s dietary quality is imperative, we must do this in ways that not only limit environmental damage but reverse it. To complicate matters further, these goals must be achieved in a changing climate, which disproportionately impacts the world’s poorest people who are already experiencing food insecurity (Hall et al., 2017).

There is now a large body of evidence demonstrating the benefits of forests and other biodiverse landscapes for rural people’s food security, primarily in low- and middle-income countries (Rasmussen et al., 2020; Baudron et al., 2019). Forests (and tree-based landscapes) can contribute to food security via four key pathways; (1) by providing nutritious foods such as fruits and green leafy vegetables for direct consumption, which can diversify diets and supply vital micronutrients, (2) by providing foods and other forest products which can be sold to generate income, which can in turn be used to purchase nutritious foods at markets, (3) by increasing agricultural productivity in surrounding areas via key ecosystem services such as soil formation, water regulation, and pollination, and (4) by providing fuelwood which can facilitate the preparation of a range of nutritious foods (Olesen et al., 2022; Vansant et al., 2022).

Despite this large and growing body of evidence, agri-food policies in low- and middle-income countries continue to be centred around increasing yields of staple crops (such as maize). Yet, these strategies often come at the expense of natural landscapes such as forests, the benefits of which are rarely (if ever) considered in agri-food policies. Similarly, these policies have done little to address wider issues around dietary quality, and in many cases have reduced the diversity and overall quality of people’s diets (Gergel et al., 2020). Further research is thus required to elucidate the complex linkages between tree-based landscapes and people’s diets. This is especially important given the increasing impact of climate change on people’s food security, and further research is required to understand whether (and how) tree-based landscapes can buffer the impacts of climate change on food security.

The overarching aim of this project is to assess whether tree-based landscapes can improve food security and nutrition in smallholder households across West Africa, and importantly, the extent to which they can buffer impacts of climate shocks. The results of this study will likely have important implications for agri-food and land use policies across West Africa and could help to better design tree-planting initiatives in order that they meet multiple goals (food security, biodiversity conservation, and climate change adaptation and mitigation).

This project will utilise data from the World Bank’s Living Standards Measurement Study (LSMS) for 13 West African countries, collected between 2021-2022, which contains detailed information on people’s food consumption, agricultural activities, living standards, and whether households have experienced climate shocks in the preceding months. These data will be spatially linked with novel satellite imagery on tree cover, which for the first time can identify trees outside of forest landscapes, and in some cases individual tree species (Brandt et al., 2020).

The candidate should ideally have a background in one of the following areas; nutrition, agricultural sciences, forestry, land system science. Experience of handling large datasets, GIS/remote sensing and R programming would be highly advantageous but is not essential.

This study will use the extensive World Bank Living Standards Measurement Study (LSMS) dataset for 13 West African countries which are freely available from the World Bank’s online data repository. Detailed metrics of dietary quality will be constructed using the available food consumption data, including dietary diversity scores, quantification of the consumption of nutritionally important food groups (such as vitamin A-rich fruits and vegetables), and intake/ adequacy levels of various macro- and micro-nutrients.

These dietary data will be spatially linked to satellite imagery on tree cover which, for the first time, allows the identification of trees outside of forests at a large spatial scale (Brandt et al., 2020). These non-forest trees have been largely absent from previous land cover maps due the limited scope of previously available satellite technologies. Tree cover (both inside and outside of forests) will be calculated in a 10km radius around each LSMS cluster (i.e., a village or cluster of households). There is also scope to assess tree cover change over time, depending on data availability.

Additionally, data on household agricultural activities (also available from the LSMS) will be examined to assess the links to diet quality and tree cover. Lastly, climate shock data (incidence of droughts and floods in the months preceding the household interviews) will also be extracted from the LSMS dataset and used to assess impacts on food security and nutrition, and if/how tree-based landscapes can buffer these impacts.

Statistical modelling will be used to examine the relationship between landscape diversity, climate shocks, and people’s food security outcomes, including the use of linear and non-linear models, mediation analysis, and matching techniques.

While this is primarily a desk-based study, there will be the opportunity for a field visit to the study region for activities such as ground-truthing, allowing the research to be placed into a real-world context. The PhD student will also form strong collaborations with research teams at the University of Copenhagen, as well as non-academic partners such as World Agroforestry (CIFOR-ICRAF). The student will present research findings at national and international conferences and will be encouraged to publish in international, peer-reviewed journals.

Year 1

 Literature review
 Extraction, cleaning & processing of LSMS data
 Extraction and organisation of tree cover data
 Construction of food security and nutrition indicators (Dietary Diversity Scores, micronutrient adequacy)
 Form collaborations with external research teams & partners
 Training activities (large-scale data analysis and GIS/remote sensing)

Year 2

 Analysis of nutritional data
 Modelling the linkages between tree cover, agricultural activity & diet quality
 Write-up of results from initial analysis
 Paper submission
 Conference attendance

Year 3

 Modelling the linkages between diet quality, tree cover, and climate shocks
 Ground truthing exercise
 Write-up of results
 Paper submission

Year 3.5

 Final publication submission
 Main thesis write-up
 Thesis submission

During this PhD project, the student will be trained in large-scale data handling and analysis, GIS and remote sensing techniques, R programming, and quantitative methods for measuring food security.

Due to the interdisciplinary nature of this project, the student will receive training in working within interdisciplinary teams, and effectively communicating between disciplines.