Soil respiration under elevated [CO₂] at EucFACE

Project leader, researchers and collaborators: Catriona Macdonald

Funding period: 

Funding agency: 

Project summary:

Soil respiration (R_soil­) is the dominant pathway by which ecosystems lose C. As such, the response of R_soil to elevated CO₂ and other possible attending effects (e.g., increased soil moisture) could strongly influence whole ecosystem C balance. Other forest FACE experiments have generally observed an increase in R_soil under elevated CO₂ of ~20%; this increase in ecosystem C loss constrained net C storage under elevated CO₂ (King et al. 2004, Bernhardt et al. 2006, Drake et al. 2011). However, these forest FACE experiments have only included young, N-limited, temperature forest trees; it is not clear if the EucFACE ecosystem will respond in a similar manner.

I propose to initiate a long-term monitoring program to document R_soil­ throughout the entire life of the EucFACE experiment. I would lead the equipment installation and data collection for at least the first two years of the project. A robust long-term record of R_soil will support and inform other areas of research at EucFACE, including root and microbe activities, the fate of canopy C assimilation, and C budgets for the site. As such, I expect a large number of researchers to be interested in the R_soil data, and I intend to maintain this as a “core” EucFACE dataset that is accessible through a frequently-updated webserver. I suggest that HIE consider a data management policy that encourages such sharing of data while allowing the CI’s/PI’s to maintain some degree of data ownership and publishing priority.

The proposed work is a collaboration between six investigators. Catriona, Ian and Brajesh will primarily use the soil respiration data to investigate how microbial community composition and function scale up to affect the ecosystem scale process of soil respiration under elevated CO₂. John, Mark, and Peter will primarily use the soil respiration data to quantify the CO₂ effect on annual fluxes, and to understand the interaction between soil moisture and the temperature sensitivity of soil respiration. Thus, the two groups plan to use these data in a largely complimentary fashion at different levels of biological organization. However, these descriptions of intended use are meant as an initial guide, not a binding contract. We will work together to refine our collaboration as the research progresses and grows. We have agreed to work as an inclusive collaborative group; we will share data collection, data ownership, and research outputs.

We propose to use the record of R_soil to address the following hypothetical predictions: