Although the spatial and temporal extent of the climatic changes is still uncertain, it is likely that the adaptive capacity of terrestrial plants and ecosystems will be exceeded in many regions. The response of these plants and ecosystems to climate change depends not only on changes in mean and variability of climatic variables but also on other environmental factors. For example, plant available water will differ depending on the pattern of precipitation, the water holding capacity of the soil and the competition with other plants. The same amount of precipitation can fall within one day or be distributed over longer time spans. This has different effects on soils with high or low water holding capacity (stronger or weaker buffer against drought) . Furthermore, interactions between changing climatic variables may affect the response of plants to new conditions. For example, a drier and warmer climate will exert stronger stress on plants than a warmer but also wetter climate. All these factors determine whether plants at a specific site will experience the changing conditions as extreme or not. The adaptive capacity of organisms and ecosystems will depend on these changes in the mean, the variability and the patterning of environmental variables.

In this session we strive to answer the following questions
• How can we quantify critical environmental conditions for plants?
• How do plants respond to changes in the mean, the variability and the patterning of environmental variables (isolated or in interaction)?
• How can plants cope with stressful conditions, where are the limits?
• What are potential feedbacks of plant responses to the carbon and water cycle under such conditions?
• What are the consequences for ecosystem function and the adaptive capacity of plants?

We welcome results from experiments, observations and modelling studies that help to understand the current and future responses of individuals and ecosystems to environmental variability, considering both the values and their temporal and spatial pattern.