Plant assemblages and conservation status of habitats of Community interest (Directive 92/43/EEC): Definitions and concepts

The article 17 of the 92/43/EEC Habitats Directive imposes to the Members States to produce periodic reports (every 6 years) on the conservation status of habitats and species at national level. In this context, in view of preparing the 4th National Report, the Italian National Institute for Environmental Protection and Research (ISPRA) drafted the national guidelines for habitats monitoring, focusing on data collection at site level. The intention of this paper is to provide an overview about the development, in Italy, on Habitat types monitoring methodologies, in particular detailing the current state-of-the-art for the parameter structure and functions, which is the most controversial among those required by the Habitats Directive for the assessment of conservation status. The paper concludes that, although habitat types monitoring programs could be carried out using individual species of fauna and/or flora, vegetation surveys represent the best choice as it allows to collect standardised and objective data, useful for the definition of more specific indicators, first of all the presence and abundance of typical species.