The DIRECT (DIversity, Rainfall and Elemental Cycling in a Terrestrial ecosystem) project was developed in 2008 by Ellen Fry, Sally Power and Pete Manning to look at the effects of climate change on a grassland ecosystem. The system uses different plant groupings and rainfall regimes to assess the effects of altering diversity on ecosystem responses to climate stresses at the field scale. The plant grouping are based on functional traits such as nutrient content, biomass and ability to fix nitrogen. The climate change treatments are based on changes in rainfall patterns predicted by climate models for southeast England.
Climatic changes like those predicted are likely to affect ecosystem processes like carbon, nutrient and water cycling. This can happen through both direct and indirect effects on plants and soil organisms. I am particularly interested in examining the effects of climate change on the links between plants and the soil microbial and invertebrate communities which regulate carbon storage and cycling. Work by Ellen Fry in the DIRECT system has shown some effects of changed rainfall regimes on properties such as net ecosystem carbon dioxide exchange, but the observed effects depend on which plant groups are present. I am continuing this work to see if effects are consistent over time and expanding it to look at soil microbial and invertebrate communities. This will provide better insight into the mechanisms that drive such changes. It will also help us to understand any wider implications for carbon cycling and sequestration in grassland soil, which may feedback on climate change.