Reproductive biology of the narrow endemic Dianthus morisianus

The thesis is concerned with the study of the reproductive biology of the critically endangered narrow endemic Dianthus morisianus Vals. (Caryophyllaceae). The species grows on the Portixeddu coastal dune system (southwest Sardinia) in only one natural population and two reintroductions. The main purpose of the thesis is to understand the reproductive system of the species and try to determine the possible causes of the narrow distribution of the species. By ex situ and in situ experiments we studied the reproductive success of the species in the only one natural population of the species and in one reintroduction. D. morisianus presented mixed matting system with high reproductive success, high synchrony among plants in the two studied populations and was highly dependent on pollinators. The species did not present neither pollen limitation nor high inbreeding depression. The reintroduced population presented high success and offspring behaved as the natural plants in the pollination experiments. After six years the reintroduction presented high success, high survival rate, produced numerous offspring and these were able to reproduce. D. morisianus is pollinated by effective diurnal and nocturnal pollinators and the main pollinators belong to the Noctuidae and Sphingidae family. This study brings some information to identify the critical aspects that affect the survival of these species, providing particularly valuable information concerning the success of reintroductions and broadens the knowledge of the studied species, being thus useful for the future development of conservation actions.