Quantifying feedbacks between plant architecture, physiology and microclimate to analyse crop climate responses

Understanding the feedback between microclimate, plant physiology and plant architecture is essential to quantify crop performance and associated food production in response to the atmospheric [CO2] elevation and warming predicted for the future. The microclimate in rice canopies depends on environmental conditions (atmosphere and soil) and on both the structural (i.e. the size and geometric arrangement of canopy elements such as leaves), and functional (especially optical and gas exchange characteristics) attributes of the canopy.

Recent developments in plant modelling allow the dynamic simulation of three-dimensional (3D) canopies using functional-structural plant (FSP) models.
These models simulate canopy development and distribution of radiation within the canopy very accurately, but they lack algorithms for the interaction of soil, canopy and atmosphere and the turbulent transport of matter and energy. The latter aspects are covered in detail in soil-vegetation-atmosphere transfer (SVAT) models, but those fail to account for crop architecture.

In this study a hybrid FSP-SVAT model will be designed and employed to quantify production and yields of rice under typical climate change scenarios. We combine this with a set of experiments in which [CO2] and temperature are manipulated under otherwise natural field conditions (in a so-called FACE-setup).
In this way we explore the effects of elevated [CO2] and temperature on the dynamic interactions between realistically structured and dynamically growing rice canopies with its microclimate, and the resulting consequences for plant and canopy performance.
More generally this study will provide a novel modelling approach to more realistically assess crop responses to climate change.