You are cordially invited to submit an abstract for your planned contribution to the conference in the form of a poster or an oral presentation.

The following thematic sessions have been approved:

Session 1: Nutrient cycling

Since the onset of elevated CO2 research, elevated CO2 and nutrient cycling were found to be interlinked as a "hen and egg" pair: Elevated CO2 influences the soil-plant cycling of macro- and micronutrients and hence the nutritional value of food and feed. At the same time, nutrient content and availability feeds back on ecosystem responses to elevated CO2 via the plant-rhizosphere-soil continuum.

Crucial questions and hypotheses such as Progressive Nitrogen Limitation or soil C sequestration under elevated CO2 atmospheres are still debated. Session 1 "Nutrient Cycling" aims to explore the feedback mechanisms between soils, microbial processes, rhizosphere and plants to identify knowns, unknowns and future research priorities.

Session 2: Phyllosphere, pests and pathogens

Plants are hosts for complex communities of a variety of microorganisms and arthropods which are present in the carposphere (fruit surface) or phyllosphere (leaf surface), including the interior of plant tissue (endophytes). They can act as pathogens, serve as mutualists or even promote plant growth. All members of such complex communities are influenced by the prevailing environmental conditions, in particular by temperature and precipitation as well as by atmospheric CO2 concentrations. Accordingly, alterations associated with climate change will have direct effects at the level of an individual species (plant, microorganism, insect) and will at the same time considerably affect composition and relationships of biotic communities.

In this session, we look for contributions presenting the current state of knowledge on the effects of climate change on communities directly associated with crop plants and other biotic interactions with relevance for crop cultivation. Presentations on the implications for future management strategies e.g. in plant protection as well as other research gaps are welcome.

Session 3: Yields and food quality

Climate change will have serious implications for future global food and feed production as crops might be negatively affected by altered temperature and precipitation regimes. In this context a challenging question remains about the role of the so-called CO2 fertilization effect. High CO2 is known to enhance photosynthesis, to reduce plant transpiration and to stimulate growth and yield.

To what extent is this realized under field conditions? and do such growth promoting effects counteract potential yield losses by climate change? How does elevated CO2 interact with other elements of climate change and with the agricultural management? Is CO2 fertilization unique for all crop species, and is crop quality really affected and how might future crop production benefit from this resource? Given projections of major short-falls in food supply by mid-Century, how can we adapt our crops to maximize yields under rising CO2?

In this session we ask for contributions from the crop, grassland and horticultural science communities that address these open questions in their research.

Session 4: Advances in FACE and manipulation techniques

The prediction of a future scenario of ecosystems with elevated atmospheric CO2 concentration is a reality in FACE experiments, where open fields or forests are exposed to CO2 fumigation. After 30 years of progress, the technical development of FACE facilities is still ongoing, for more advanced fumigation controls and challenging types of ecosystems. We welcome abstracts with all technical aspects showing optimization of CO2 fumigation, identified artifacts such as gradients within FACE rings, challenges such as large scales (grand forest / wide rings) and combinations with additional treatments (e.g. grazing or warming). Research work may also cover natural CO2 release sites and statistical / experimental strategies of using such sites.

Session 6: Ecophysiology

The photosynthetic response to elevated CO2 has always been considered to drive the effects on yields and yield quality, soil-rhizosphere interactions, nutrient cycling and greenhouse gas fluxes; it is hence implemented in global C cycle models. The session aims to explore the mechanisms, importance or indifference of the atmospheric CO2 concentrations from past to future conditions as cause of ecosystem effects.

We seek for contributions that investigate the impact of elevated CO2 on plant physiology, plant architecture, phenology, or water and nutrient use. We particularly look for studies that consider C3 and C4 plants as well as annual and perennial plants and crops.

Session 7: Modelling and meta-analysis

Projections into the future of climate change impacts are only possible by models. No matter whether empirical or deterministic models are used, reliable field data are mandatory for model development, calibration and validation. What sets of data do modellers need? Which processes and feedback mechanisms need to be considered by models? Why do feedback loops we know not act the way we expect them to work – is it because of compensating processes or is the feedback not of a sufficient magnitude to affect the ecosystem response?

This session will foster the discussion between experimentalists and modellers. We look for presentations of (1) data-driven models to identify relevant processes and mechanisms, (2) process-oriented model set-ups at all spatial scales, (3) upscaling from plot to regional scale, and (4) the uncertainty in model projections

Session 8: Trace gas emissions

There is now mounting evidence that climate change has an effect on emissions of greenhouse gases (GHG), such as CO2, CH4 and N2O, from our ecosystems. What do we know about the feedback effects of elevated CO2, with or without other climate change factors such as warming, on GHGs in various ecosystems? Do we know which processes are affected and are the reactions ecosystem dependent? What are the key areas we need to focus on to obtain a more complete picture of future GHG emissions from our ecosystems?

This session aims to summarize our knowledge on GHG emission from FACE studies and tries to provide an outlook for future research activities in this area. We are looking for contributions that (1) summarize our knowledge on GHGs under elevated CO2 from various ecosystems; (2) explore feedbacks of elevated CO2 on GHG production processes and, and (3) provide an outlook of advanced techniques, such as state-of-the-art isotopic techniques to identify the GHG process changes under elevated atmospheric CO2 levels.