Impacts of savanna tree encroachment on livelihoods, water and carbon

Savanna ecosystem covers nearly half of Africa supporting various livelihoods. They are important in providing several services such as groundwater recharge, supporting livelihoods and wood for charcoal. However, increasing carbon dioxide concentrations in the atmosphere have known to have accelerated the encroachment of trees into the savannas in the last 50 years threatening various ecosystem functions and services. At the local scale, rainfall, fire and herbivory act as drivers of this phenomenon of tree encroachment.

Tree encroachment is known to impact the carbon and water cycles where the ecosystem functions as ‘sources’ or ‘sinks’ of carbon.  In my research, I intend to understand the relationship between tree encroachment and ecosystem carbon and water exchange. Eddy covariance towers have been set up at encroached and unencroached sites at Eastern Cape, South Africa, to measure the carbon and water fluxes.

The research also focuses on understanding what tree encroachment means for livelihoods of people in the savannas. I will build an understanding of land-use in encroached savannas using participatory research methods to map resource-use, livelihoods and the institutional landscape of land governance in the Eastern Cape.

This research is a collaborative work with Prof Brad Ripley, Department of Botany, Rhodes University, South Africa.

As a part of science communication, I am engaged as a writer with Research Matters, a science communication initiative in India. I write on a diverse range of topics from ecology and climate studies to social sciences.


Rodrigo León Cordero, Suma M, Siddhartha Krishnan, Chris T. Bauch, Madhur Anand (2018) Elements of indigenous socio-ecological knowledge show resilience despite ecosystem changes in the forest-grassland mosaics of the Nilgiri Hills, India. Palgrave Communications Volume 4, Article number: 105 (2018)

Suma Mani


Professor Colin Osborne

Professor of Plant Biology


Professor Frances Cleaver

Professor in Human Geography