Research_

Biogeochemistry laboratory

Carbon, nutrient and water cycles in plant-soil systems

We investigate carbon, nutrient, and water dynamics in grasslands, forests, and agricultural systems, and how these dynamics are affected by climate and land use change.

Biogeochemistry field testing site — Rainout shelter experiment at John Bruce Pye farm

Our aims

Our aim is to gain a better understanding of plant-soil interactions affecting carbon, nutrient and water cycles to make better predictions of ecosystem responses to climate change and to develop mitigation and adaption strategies for global change.

Our research

Rhizosphere priming effect

The rhizosphere priming effect is caused by plant roots enhancing or inhibiting microbial decomposition of soil organic matter. In our group we investigate the mechanisms and consequences for soil carbon storage.

Carbon costs for plant nutrient uptake

Plants need nutrients to grow, which are taken up from the soil, but which are also internally recycled. Surprisingly, little is known about the carbon costs for nutrient uptake and recycling and how these costs affect plant growth under different environmental conditions. We examine the role of fungi and bacteria in the exchange of carbon and nutrients with plants.

Biochar effects on soil carbon, nitrogen and phosphorus dynamics

Biochar as a soil amendment has the potential to significantly increase soil organic carbon. We examine effects on decomposition and mineralisation, carbon use efficiency and turnover, as well as sorption and desorption processes in soils applied with biochars at different stages of oxidation.

Nitrogen and phosphorus interactions

Human activity has altered nitrogen and phosphorus availability in most terrestrial ecosystems. We examine how availability of phosphorus in soils affect nitrogen transformations, plant uptake and loss. We are further interested in how plant growth and microbial activity are constrained by the stoichiometry of nitrogen and phosphorus.

Most of our studies are done in the context of climate and land use change in grasslands, forests, and agricultural systems. Much of our work relies on stable and radioactive isotope techniques to elucidate specific processes.