- Effects from climate change, adaptations and
greenhouse gas reduction at 2050

Abstract:

Satellite map of the Umweltbeobachtungs und Klimafolgenforschungsstation Linden

Abstract:

The presentation of the Working package B2 at the general assembly of the FACE2FACE consortium at the 4th of July, 2017.

Abstract:

Overview of the model setup for the Giessen FACE grassland ecosystem, including preliminary simulation results for CO2 emissions and outlook.

Abstract:

An increase in mean soil surface temperature has been observed over the last century and it is predicted to further increase in the future. The effect of increased temperature on ecosystem carbon fluxes in a permanent temperate grassland, was studied in a long term (6 years) field experiment, using multiple temperature increments induced by IR-lamps. Ecosystem respiration (R-eco) and net ecosystem exchange (NEE) were measured, and modelled by a modified Lloyd and Taylor model including a soil moisture component for R-eco (average R2 of 0.78) and inclusion of a photosynthetic component based on temperature and radiation for NEE (R2=0.65). Modelled NEE values ranged between 2.3 and 5.3 kg CO2 m-2 year-1, depending on treatment. An increase of 2 or 3°C led to increased carbon losses, lowering the carbon storage potential by around 4 tonnes of C ha-1 year-1. The majority of significant NEE differences were found during night-time compared to daytime. This suggests that during daytime the increased respiration could be offset by an increase in photosynthetic uptake. This was also supported by differences in ?13C and ?18O, indicating prolonged increased photosynthetic activity associated with the higher temperature treatments. However, this increase in photosynthesis was insufficient to counteract the 24hr increase in respiration, explaining the higher CO2 emissions due to elevated temperature.

Abstract:

A major issue of our today's research is to help meeting the challenges of future food security. One task is to assess and develop crop management strategies adapted to predicted future climatic conditions. Yet, both the variability of environmental conditions and the uncertainty of climate projections as well as the orchestra of multiple plant responses and their interaction with the environment make it difficult to predict plant behavior in the field. Recent studies have demonstrated the usefulness of classical crop models as a tool to investigate crop productivity under predicted climate conditions. These models use data on plant architecture only to a limited extent as they usually follow a systems approach by focusing on processes for predicting dry matter production. However, plant architecture is a major determinant of the crops’ resource use efficiency. Moreover, plants show time dependent structural changes as they grow and develop, and these processes are affected by various environmental factors and stresses. Virtual plant models consider both the three-dimensional plant architecture and concepts of plant physiology. Here, we outline the way in which virtual plant modelling can further improve our understanding on the impact of climate change on food production. Greenhouse and growth chamber experiments may serve as data sources for model parameterization, in particular of response functions with respect to environmental stimuli. Data from field experiments in free air carbon enrichment (FACE) facilities, such as those obtained in the new Geisenheim FACE for special crops, may be used to evaluate virtual plant models with respect to future climatic conditions. A combination of field data and virtual plant model simulations may then allow us to assess the specific role of plant architecture in resource use efficiency and help to develop advanced strategies for future crop production.