Confronting Ecosystem Models with Experiments: Data Assimilation
Using a technique called data-assimilation, we can inform existing ecosystem models with measurements from field experiments. In combination with meta-analysis, this approach becomes a powerful statistical tool to improve our predictions of ecosystem responses to global change. We recently used data-assimilation to study the effect of warming and CO2 enrichment on ecosystem carbon dynamics.
Do Soils Store more Carbon in a Warmer World?
Field warming experiments have been set up worldwide to address whether climate warming will reduce soil carbon storage. Why is his important? Because when soils release more carbon than they take up, more ends up in the atmosphere. Thus, soils, through losing more carbon, could in fact accelerate the pace of climate change. Using a combination of data assimilation and meta-analyses we synthesized and evaluated plant and soil responses to warming using data from field experiments. Our study is currently in review. For more information, contact Natasja van Gestel.
In a related study, we combined data-assimilation with meta-analysis to synthesize published research on soil C dynamics under elevated CO2. We combined measurements of plant production, microbial respiration, and soil C stocks to estimate CO2 effects on soil C turnover, thereby providing insight into the mechanisms determining long-term soil C storage. We derived effect sizes from a one-pool biogeochemical model of soil C cycling, the same form used by several global C cycling models. We found that elevated CO2 increases the decomposition rate of soil carbon, thereby limiting the potential for soil C storage.
Van Groenigen KJ, Qi X, Osenberg CW, Luo Y, Hungate BA, 2014. Faster decomposition under increased atmospheric CO2 limits soil carbon storage. Science 344, 508-509.
Van Gestel N, Shi Z, van Groenigen KJ, Luo Y, Osenberg C, Dukes JS, Andresen LC, Michelsen A, Schuur T, Hungate BA. Little change in soil carbon storage with warming. Under review.