Studi di biologia della conservazione di specie vegetali endemiche della Sardegna nell'ambito del progetto “GENMEDOC”

Abstract

Numerose specie rischiano l'estinzione poiché si trovano in habitat soggetti a frammentazione o in aree sottoposte a disturbo antropico, oppure presentano un numero ridotto di popolazioni o di individui riproduttori (Griggs, 1940; Stebbins, 1942; Drury, 1974;Rabinowitz, 1981;Snogerup, 1985;Lavergne et al., 2004). Alcune tra queste sono naturalmente rare, altre lo stanno diventando, soprattutto nel bacino del Mediterraneo, a causa, diretta o indiretta, del disturbo antropico o ancora per cause naturali (Montmollin de & Strahm, 2005). Gli studi di biologia della conservazione, che comprendono analisi popolazionali, indagini demografiche e relative alla biologia riproduttiva, consentono di valutare lo stato di conservazione delle specie e la possibilità di sopravvivenza a lungo termine delle popolazioni, agevolando l'individuazione di strategie per la loro gestione e protezione. Accettato il 18 Settembre 2008Conservation biology studies on the endemic species from Sardinia within the "GENMEDOC" Project -The achieved results of the Interreg IIIB "Genmedoc" project (2004)(2005)(2006) are here reported. Data focused on the conservation biology studies of Sardinian endemic species are showed in this work. During the project 26 populations of 16 species were investigated and the ex situ conservation for these species was guaranteed by storage of 65 seed lots in the seedbank. Furthermore 8 species were analysed by in situ characterization of 17 populations: for each population ecological studies were carried out. Real and possible threats that affect these populations were detected. For 6 species effective germination protocols were identified and also valied by other two project partners. These protocols allow evaluating seed quality for the stored lots and their longevity during next years; moreover the knowledge of the best germination conditions will be able to schedule a possible cultivation or an in situ re-introduction for these species. These results were obtained by sistematic conservation biology studies of threatened endemic species of Sardinia by a tested and internationally acknowledged methodology.

Ecological remarks onAstragalus maritimusandA. verrucosus, two threatened exclusive endemic species of Sardinia

“…The application of pretreatments showed that seeds of both species feature a germination inhibition due to tegument impermeability (physical dormancy, sensu Baskin & Baskin 1998, as already reported for other species of this genus (Baskin & Quarterman, 1969;Kaye, 1999;ISTA, 2006) and more generally for species belonging to the Fabaceae family (Rolston, 1978;Grime et al, 1981;Baskin & Baskin, 1988;ISTA, 2006) and as already observed in A. maritimus by Bocchieri et al (2000) and for both species by Bacchetta et al (2008b).…”

“…Seed lots stored in BG-SAR (Bacchetta et al, 2008b; see Table I for seed lots details) were tested by applying different experimental pretreatments, in order to break physical dormancy. In particular, seeds were scarified by using sand paper, by immersion in H 2 SO 4 at 96% for 5, 15 and 30 minutes and in boiling water (100 °C) after removing them from the heat source (Piotto et al, 2001).…”