Our process-oriented research at the Chair for Ecophysiology of Plants in the fields of experimental plant ecology and ecophysiology is focused on woody plants and provides the basis for teaching botany and dendrology. The scope is on the structure and function of plants and their growth performance, as resulting from their adaptations to natural environment, including physiological and ecological characteristics and sensitivities to natural and anthropogenic stress. Particular interest is on carbon, water and nutrient relations and associated efficiencies in above and belowground space exploitation and resource use, highlighting mechanisms of allocation and competition, root-shoot interaction and stress defence. Stress scenarios are considered as combinations of competitive and pathogenic influences, varying light, water and nutrient availabilities, and elevated ozone and CO2 regimes. Accordingly, employed methodologies analyze above and belowground growth and structural differentiation, photosynthesis, respiration, transpiration and stomatal regulation, sap flow and phloem transport as well as stable isotopes for quantifying resource flux and underlying mechanisms. One central research site is "Kranzberg Forest", which has been the core of interdisciplinary research programs like SFB 607, CASIROZ and currently Kranzberg Forest Roof Experiments (KROOF), all coordinated by the the Chair for Ecophysiology of Plants.