Endangered plants: a comparison of applied methods for the assessment of extinction risk for rare plants in Italy

In this chapter we discuss how to assess the risk of extinction for plants using two different methods and six different species as case of study from the Mediterranean, namely from Campania, an administrative region of Southern Italy. Italy falls within one of the most important hotspots for biodiversity of the world: the Mediterranean region. In Italy, plant biodiversity is particularly rich, with some 7500 species with a high rate of endemics (13.5%). A great number of these species is currently exposed to various threats in spite of the existence of international, national and regional laws to protect them. Institution of protected areas or measures for species conservation is often ineffective without an assessment of the actual risk of extinction of a taxon. The most acknowledged method to evaluate this risk is the IUCN protocol for the creation of Red Lists, which is widely used worldwide for both animals and plants. Other approaches have been developed as well, like the creation of the Red Numbers in Israel, which is designed specifically for plants. Both procedures point out the importance of an evaluation as much quantitative as possible in order to avoid excessive subjectivity when measures are taken to preserve one species rather than the other. In this chapter, even though these two different methods are not meant to be alternatives, we will juxtapose them using as case study the plants growing in Campania in order to allow a comparison of both methods at a regional scale and to detect possible flaws in either methodology, in terms of conservation of plants, on the basis of detailed data which have been collected during field surveys. The applied approach highlights the challenges and complexity of evaluating the risk of extinction for plants, which is the basis for conservation of both species and habitats.