Populations studies on two endemic taxa of southwestern Sardinia: Dianthus morisianus Vals. (Caryophyllaceae) and Anchusa littorea Moris (Boraginaceae)

In the Mediterranean region as elsewhere, intense coastal development has resulted in widespread modification of coastal ecosystems. Here, coastal sand dunes represent an extremely vulnerable habitat to many forms of disturbance, including those connected with recreational tourism which in recent years has increasingly contributed to the destruction and fragmentation of natural coastal habitats. This study concerns two narrow endemic plants growing on coastal dune systems of southwest Sardinia. Anchusa littorea Moris is a short-lived species of open dunes and D. morisianus is a perennial species which grows on stabilized dunes. The only natural populations of these species are located in southwest Sardinia. Like many other rare species of this type of habitat we know little of the reasons for their extreme rarity, making it difficult to identify and recommend conservation actions. The thesis provides a detailed investigation of the population ecology of the existing populations of the two species with the aim of identifying the constraints on their viability. Specifically, the aims of the present study were to analyze the following features: To investigate the conservation status of this species; To individuate and quantify the main threats acting on this population; To analyse some critical stage of their life-cycle (i.e. modeling of emergence and germination); To evaluate the phenological pattern; To propose adequate conservation measures. Three years of study has been reveal some critical elements in the ecology of the species and their rarity and the investigation of each biology aspect about these psammophilous endangered plants yielded the information needed in order to identifythe critical aspects that affect the survival and toguide the proposal and implementation of conservation measures.