We are currently starting a new project in the Macrocosms platform. The project is entitled "Agriculture’s Global Warming Potential: multilateral approaches for predictions", and has the overarchig aim of addressing the urgent need for metrics and tools that allow the comparison of multiple management policies while taking into account the spatio-temporal variability of the three main greenhouse gases (GHG: CO2, N2O and CH4) simultaneously. The global warming potential (GWP) is one such metric, but can be rarely applied due to lack of simoultaneous measurements of CO2, N2O and CH4. Therefore, the models used to estimate the impact of agricultural practices on GHG emissions suffer from rather large parameter uncertainties. With the help of an Ecotron experiment in the Macrocosms platform hosting large reconstructed ecosystems from the EFELE site we will address the following following shortcomings: 1) measure the three main GHG to estimate the GWP, 2) imporove our mechanistic understanding of how soil biota (notably earthworms) contributes to the GHG emissions and 3) fill knowledge gaps related to how soil biota and nitrogen (N) amendments affect the microbial communities involved in N2O emissions (i.e. nitrifiers and denitrifiers).
A prototype of the air conditoning systems is currently being tested before commissioning sixteen units. The Mesocosms platform will be fully functional by the end of 2017 and ready to host projects in 2018 because two ANR projects involving expeirments in the Mesocosms have been already funded:
1) In 2018 the Mesocosms platform will host an experiment planned in the ANR-funded (Biodiversa - SOILforEUROPE) project led by Dr. Stephan Hättenschwiler and entitled "Predicting European forest soil biodiversity and its functioning under climate change".
2) In 2019 the platform will host another experiment planned in an ANR-funded (JCJC) project entitled "Transgenerational effects and physiological responses to drought recurrence in holm oak (Quercus ilex)" and led by Dr. Alexandru Milcu.
A project run by Dr Anne Alexandre (PI) and entitled "Towards a new proxy of continental atmospheric humidity: the triple oxygen isotopic composition of plant biosilica" is currenlty beeing caried out in the micocosms (funding INSU, LEFE-IMAGO). The project aims to adress the serious lack of proxies suitable for reconstructing, in a quantitative way, past changes of continental atmospheric humidity. The experiments will expore the feasability of using the 17O-excess of plant biosilica as a new proxy for air humidity.