May 12, 2015

Tropical Forest Roots and the Regulation of Greenhouse Gases

Nick Girkin- University of Nottingham


  • Sofie Sjogersten
  • Nick Ostle
  • Nial McNamara
  • Ben Turner


Tropical forested peatlands are important carbon stores as well as sources and sinks of greenhouse gases and cover 4.41x103km2, but are under pressure from climate change and human land use alterations. Plants roots release carbon as ‘root exudates’ deep into the waterlogged soil profile enabling methane production my specialised bacteria. The release of oxygen can convert produced methane into carbon dioxide emissions which can also be emitted. This project aims to understand the relationship between these two processes, resulting in an invaluable piece of ecological knowledge regarding the drivers of climate change, and with implications towards land management.


To identify the recent impact of photoassimilates (plant sugars) released from the roots on methane emissions from the soil, Nick’s research utilises a novel technique with a stable 13C isotope tracer injected into the stem of two contrasting types of tropical vegetation in Panama: palm trees and broadleaved evergreens. This will allow him to track the flow of carbon from the plant into the soil and onwards. Complimenting this will be lab based incubation research as well as field based trenching experiments which will manually sever roots and stop the flow of root exudates.

Why This Subject Matters to Them

“Tropical peatlands are a globally important carbon sink and are relatively understudied compared to boreal and temperate systems. This project offers the opportunity to conduct original research in an exciting area of science with the potential to inform further approaches in the field. The project also contributes more generally to land management approaches and the broader understanding of the impacts and drivers of climate change, and therefore allows me to contribute to one of the most significant scientific questions.”