Towards a new multidimensional indicator of tree crown status.

Foliar features can be subdivided into morphological, chemical, and physiological traits, disease or damage symptoms. Foliar analysis of forest trees is, usually, employed in large scale monitoring programmes, taking into account only chemical traits. Leaf collection may be the most difficult, time-consuming and costly phase of a field survey. It is recommended that once a sample is collected, a multiplicity of foliar analyses be carried out. Within FunDivEUROPE project an integrated approach of foliar sampling and analyses was conducted in six European forest types. The surveys performed include chemical analysis (total nitrogen and carbon leaf content, carbon stable isotopes), physiological analysis (chlorophyll a fluorescence) and symptoms (presence and diffusion of insects and pathogens).The aim of the presentation is to explore the correlation between leaf traits and make an attempt to combine different parameters describing aspects of crown status into a synthetic indicator that estimates tree responses to climate variables and diversity. The current study focuses on comparing compensative and non-compensative approaches to synthesizing foliar data, by considering which method is more appropriate to the studied phenomena and type of data.