Alessandro is interested in the eterminants of species richness and composition at different spatial scales and the problems associated to sampling species richness at larger spatial cales. This is done using a variety of methods, including the analysis of pecies distributional data, field plots, field experiments and data modelling. t present, Alessandro is President of the Teaching Committee of the Master evel course in Biodiversity and Nature Conservation of the University of Siena nd he is Chief Editor of the Journal of Vegetation Science and Applied Vegetation Science.