Global Biogeochemistry


header image of a wetland, a flux tower, fieldwork and farmland

Our work considers the global cycling of major biologically and radiatively important elements and chemicals, principally from the perspective of their interactions between Earth’s terrestrial surfaces, the ecosystems they harbour and the atmosphere. We use many different approaches to quantify how these biogeochemical cycles are altered by global change.

A major focus of our research activity is seeking to understand how forests, wetlands and rivers interact with the atmosphere through the exchange of powerful greenhouse gases such as carbon dioxide, methane and nitrous oxide. This includes understanding the transformations involved and the pathways of exchange of these greenhouse gases from microbial to global scales; from the deep past and into the future.

Experimentally, we harness the power of large-scale manipulation experiments such as the Birmingham Institute of Forest Research free air CO2 enrichment experiment (BIFoR FACE) and allied experiments in Australia and Brazil to understand how future atmospheric carbon dioxide enrichment alters the function of forests with respect to the carbon cycle and major nutrient cycles. How nitrogen is transformed in both natural ecosystems and agroecosystems is a key area of activity with soils the principal locus of transformation of inert nitrogen gas and applied fixed nitrogen, into various reactive nitrogen species that are of relevance to climate change, water quality, crop nutrition and eutrophication of our waterways. How carbon and nitrogen are cycled within river systems is also a key focus particularly with respect to greenhouse gas exchange with the atmosphere and investigating key drivers such as future global change including climate and land-use, furthering understanding of global carbon and nitrogen cycles and connecting terrestrial ecosystems to ocean reservoirs.

Our research is increasingly concerned with the exchange of methane between wetlands, forests and the atmosphere. Atmospheric methane is rapidly increasing in concentration which is challenging the world’s ability to stay within Paris Agreement climate guardrails. There is therefore an urgent need to understand how natural and human-modified ecosystems participate in the methane cycle so that climate action can be given its proper context. We use a combination of field measurements and global modelling (across time) to narrow uncertainties in the size of the most important source and sinks of atmospheric methane.

Research areas

Current research in the group considers:

  • The global carbon cycle and the role of terrestrial ecosystems, under global change
  • The global methane cycle including quantifying sources and sinks within terrestrial ecosystems and other land uses and understanding their responses to agents of global change over long time scales
  • The global nitrogen cycle with a particular focus on agricultural use and ecosystem use under future atmospheres (elevated CO2)

Ongoing projects include:

Agricultural ditches as hotspots of greenhouse gas emissions

Agricultural ditches have recently been identified as hotspots of greenhouse gas emissions within river systems and potentially represent an additional source of emissions to the atmosphere from agricultural activity. This project focusses on all three major greenhouse gases (CO2, CH4, N2O) from agricultural drainage ditches across the North China Plain, where we are investigating seasonal patterns and drivers of greenhouse gas fluxes in-situ as well as using laboratory incubation experiments to further understand processes and drivers of greenhous gas emissions. This project is being led by Prof. Zhifeng Yan at Tianjin University, China.

Effects of land-use on stream microbial-biogeochemical cycling

Streams and rivers process a significant amount of the carbon and nitrogen they receive from terrestrial ecosystems during transport to the ocean. While we now acknowledge that the greenhouse gas emissions from these systems to the atmosphere are an important component of global greenhouse gas fluxes we still lack understanding of the drivers of these fluxes and do not fully consider the coupled role of microbial communities in these processes. This project aims to unravel the drivers of microbial-biogeochemical cycling (greenhouse gas fluxes and denitrification) across a land-use gradient in headwater streams in Massachusetts, USA, considering both streambed and riparian sediments as hotspots of biogeochemical reactivity within river corridors. This project is in collaboration with Dr. Ashley Bulseco at the University of New Hampshire, USA.

Research funding

Our research is supported by UKRI, (principally NERC), the Royal Society, the Leverhulme Trust, the EU and other bodies including SPARK Climate Solutions.

Postgraduate opportunities

PhD Funding Sources

We are part of the CENTA DTP which is the first port of call for funding, but other opportunities are often available, and we are always keen to talk to potential students about opportunities.