FACE Underground 

The NERC funded FACE Underground Project has its own website. To keep updated on this research please visit their website.

In summary, this a NERC standard grant, “FACE Underground” was awarded in June 2019, scoring 10/10. The research will provide mechanistic detail to complement the budget analysis in the QUINTUS Large Grant, and the food web analysis in the Fast-C standard grant led by Dave Johnson (University of Manchester).

FACE Underground will use the FACE experiment to determine whether mature temperate forests will be able to access more soil nutrients under elevates carbon dioxide (eCO2) and therefore, whether there is likely to be a large and sustainable carbon sink in these ecosystems, addressing major uncertainty in carbon modelling. If our results suggest that the forest uptake will become increasingly nutrient limited in the future then it would have major societal implications, as great cuts in greenhouse gas emissions would be needed to avoid the most dangerous consequences of climate change.

Objectives

  1. Determine the effects of eCO2 on below ground C allocation to different nutrient acquisition strategies including fine root production, rates and types of root exudation, and association with mycorrhizal fungi

  2. Assess the role of these mechanisms in controlling rates of decomposition, soil microbial community function, and N and P availability.

  3. Evaluate how N uptake capacities and preferences of tree roots change under eCO2 and whether these changes are related to the effects of eCO2 on N transformation rates.

The research will be undertaken in three plots under eCO2 and three control plots. We will measure root and mycorrhizal hyphal production, and the release of substrates (exudates) from roots throughout the year. We will also carry out a series of experiments to determine the relative roles of roots versus mycorrhizal fungi in controlling rates of decomposition and nutrient cycling, and the extent to which these are affected by eCO2. These decomposition experiments will involve root and/or mycorrhizal fungi exclusion, as well as a novel approach for simulating root exudation. The results will enable us to determine whether, and through which mechanisms, trees can stimulate decomposition and nutrient mobilization under eCO2. Finally, we will determine if the types of nitrogen containing compounds that roots take up changes under eCO2 and how this relates to their availability in the soil.