Impacts of savanna tree encroachment on livelihoods, water and carbon

The Grantham Centre for Sustainable Futures focuses on advancing sustainability research and connecting it with the policy debate around how humans can live in a more sustainable way.
grantham.sheffield.ac.uk

We are recruiting Scholars who will combine outstanding intellect with a strong commitment to public engagement, leadership and action. These ambitious individuals will complete interdisciplinary PhD research projects to help solve the challenges of sustainability. They will be supported by the Centre through a unique training programme, designed to equip them with the skills to become policy advocates and leaders in sustainability matters.
http://grantham.sheffield.ac.uk/wp-content/uploads/2017/12/Grantham-Scholars-training-brochure.pdf

Your application for this studentship should be accompanied by a CV and a 200 word supporting statement. Your statement should outline your aspirations and motivation for studying in the Grantham Centre for Sustainable Futures. You should also outline any relevant experience and interests that you have in sustainability issues.

Please select ’Standard PhD’ and the ’Department of Animal and Plant Sciences’ which is where the lead supervisor is based. Fill in the title of your desired project and the name(s) of the supervisors. The starting date of the PhD will be the start of the next academic year - 1 Oct 2018. The ’Funding stage’ on the form will be ’project studentship’.

Savannas cover half of Africa, supporting the livelihoods of hundreds of millions of people through grazing for livestock, groundwater recharge, and wood for charcoal. However, these goods and services are increasingly threatened by tree encroachment, which may eventually convert grassy savannas into thickets or forests. Tree encroachment is occurring on massive scales and at an accelerating rate. This multidisciplinary project aims to understand: i) the relationships between tree encroachment and the goods and services provided by savannas, with a particular focus on ecosystem water and carbon exchange; and ii) the contributions of savanna ecosystems to people’s livelihoods, with an emphasis on the ways in which local, regional and national institutions are involved in land management, and how people understand the encroachment problem. The PhD student will be trained in eddy covariance and participatory research methods, carrying out their fieldwork and working with stakeholders in the Eastern Cape of South Africa.

Savannas have a ground layer of grasses that supports grazing for livestock and wild animals, and a sparse layer of trees that enable groundwater recharge and provide wood for charcoal. These ecosystem goods and services are currently threatened at the continental scale by tree encroachment, thought to be caused by faster tree growth under rising atmospheric CO2. In this multi-disciplinary PhD, the student will examine what tree encroachment means for ecosystem function and the livelihoods of people in savannas. The project has two components:

1. Ecosystem Science: How does encroachment impact ecosystem carbon sequestration, catchment water budget, and the production and quality of grass for livestock? Are there critical thresholds of tree cover that cause rapid gains or losses of carbon stocks, groundwater or grass? The student will directly measure carbon stocks and grass production along gradients of encroachment, and use eddy covariance towers to compare CO2 and H2O fluxes in encroached and unencroached landscapes.

2. Social Science: How do the managers and users of land understand tree encroachment, and which local, district and national institutions are involved in managing the problem? Are there contradictions between the local, political and scientific understandings of tree encroachment and its consequences? The student will build an understanding of land-use in encroached savannas by using participatory methods to map the resource-use, livelihoods and institutional landscape of land governance.

The PhD research will use field sites in the Eastern Cape of South Africa as case studies, collaborating especially with Professor Brad Ripley from Rhodes University.