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Tesi etd-02282014-160549


Thesis type
Tesi di dottorato di ricerca
Author
CARTA, ANGELINO
URN
etd-02282014-160549
Title
AN INTEGRATED APPROACH TO THE CONSERVATION OF PERIPHERAL ISOLATED PLANT POPULATIONS
Settore scientifico disciplinare
BIO/02
Corso di studi
SCIENZE BIOLOGICHE E MOLECOLARI
Commissione
tutor Bedini, Gianni
tutor Peruzzi, Lorenzo
commissario Gargano, Domenico
Parole chiave
  • seed ecology
  • plant reproduction
  • Peripheral populations
  • distribution modelling
  • conservation
  • climate change
Data inizio appello
07/04/2014;
Consultabilità
completa
Riassunto analitico
Peripheral isolated plant populations at the margin of a species range may be exposed to ecological and evolutionary processes that differ from central populations. Peripheral populations may have either a high evolutionary potential or be prone to extinction and therefore, they are considered an important source of biodiversity and included in conservation actions.<br>This work addresses the identification of PIPPs in Tuscany and the analysis of the main patterns of biological and ecological strategies which allow PIPPs to survive. I assessed the state of knowledge about the PIPPs in Tuscany, by means of a combination of different approaches ranging from quantitative floristic analysis, seed ecology experiments, mating system investigations and species distribution modelling.<br>Based on the results, many disjunct species of different geographical affinities occur in Tuscany. Few relationship between germination niche width and distribution range were found. Indeed, plastic responses, such as seed dormancy variation modulated by local climate and mixed mating system, may be successful reproduction traits under mosaic and unpredictable habitats. These outcomes support the idea that peripheral populations may be able to cope with ecological and biological constraints. On the contrary, distribution modeling approach predicted low survival of peripheral populations under unbalanced climatic conditions.<br>Distribution modeling established a fundamental baseline for assessing the consequences of climate change on peripheral populations. Specifically, ‘core localities’, that could have the potential to withstand climate change, were identified. The populations occurring there could serve as long-term in situ stocks and others that are predicted to be under threat from climate change, presently and in the medium term, represent assessment priorities for ex situ conservation.<br>The combination of different approaches have significantly improved the knowledge of Tuscan PIPPs, however, further studies are required to assess genetic drift and genetic divergence compared to narrow endemic species to understand adaptation processes.<br>I conclude that a strategy aimed at conserving the evolutionary process underlying PIPPs requires different action levels and particularly a “fine-filter approach” is required through (1) selecting sites where they occur for habitat protection (e.g. micro-reserves) and by (2) ex situ strategies based on sampling strategies of populations that maximize the genetic diversity of the taxa in the seedbank collection.<br>
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