Accessibility statement

Rebecca Kariuki
PhD Student and Marie Curie Early Stage Researcher



I am interested in understanding the changes in space and time in the interactions between ecosystems, climate and societies in East African savannahs. Specifically, I am interested in assessing the link between human population growth, socio-economic development, grazing and sedentarization in East African savannahs. Additionally I would like to establish the response of vegetation structure and distribution to changes in climate and human activities.

Prior to the commencement of my PhD in 2014, I worked at African Conservation Centre (ACC) and other consultancies in Nairobi, Kenya. Some of the projects I was involved in include: ‘Assessing the effectiveness of wildlife barriers surrounding the Mt. Kenya ecosystems’, ‘Maasai attitudes towards wildlife’, ‘Plant size structured savannah ecosystems’ and Environmental and social impact assessments. My MSc thesis investigated the effects of cattle grazing and trampling, as management tools, on herbaceous vegetation quality of semi-arid rangelands of central Kenya.



PhD in Environmental Geography

Department of Environment and Geography, University of York  


Assistant Conservation Scientist

African Conservation Centre (ACC), Nairobi, Kenya
MSc Biology of Conservation School of Biological Sciences, University of Nairobi, Kenya
BSc Chemistry and Zoology School of Biological and Physical Sciences, University of Nairobi, Kenya




Modelling Past, Present and Future Ecosystem, Climate and Human Interactions in East African Savannahs

Supervisors: Dr. Rob Marchant, Dr. Phil Platts, Dr. David Western and Dr. Simon Willcock

Funding: Marie Curie Initial Training Network

Description of Thesis

Savannahs are tropical and subtropical biomes characterized by varying proportions of woody plants and grasses. In East Africa, they are home to humans, livestock and wildlife. In addition, they provide ecosystem services to a wide range of people. The main factors governing vegetation distribution and community structure of savannahs are rainfall, soil nutrients, herbivores, fire and human beings.

The LPJ GUESS is a dynamic global vegetation model which can simulate vegetation dynamics and composition in response to changing climate, atmospheric CO2 concentration and nitrogen deposition. It can also be coupled with other models and used to simulate vegetation patterns under human disturbance.

Savannahs have changed greatly over time largely due to human activities and climate change. Modification in savannahs leads to modification of critical ecosystem services thus reconstructing past and present ecosystem, climate and human interactions is vital for predicting future interactions.

The focus of my PhD will be to assess the spatial and temporal changes in the interactions between ecosystems, climate and societies in East African savannahs using the LPJ-GUESS, agent based, grazing and water models. To achieve this, the following objectives will be addressed:

  • To understand temporal, spatial and social changes in grazing and sedentarization in East African savannahs
  • To establish the response of vegetation structure and distribution to climate change and human activities
  • To predict the future responses of vegetation structure and distribution to changes in climate, land use and socio-economic development.

This research will determine the effects of grazing and sedentarization on vegetation structure and composition. It will also determine the effects of climate change on savannah ecology as well as produce ecological, socio-economic, biogeochemical and climate models for East African savannahs.

Research group(s)

York Institute of Tropical Ecosystems (KITE)

Resilience in East African Landscapes (REAL)


Full publications list

Kariuki, R.W (2010) Effects of Cattle Grazing and Trampling on Herbaceous Vegetation Quality of Semi-arid Rangelands of Lewa Wildlife Conservancy, Laikipia, Kenya. Master’s thesis. University of Nairobi, Kenya.

Contact details

Rebecca Kariuki
Department of Environment and Geography