Università degli Studi di Cagliari DOTTORATO DI RICERCA Botanica Ambientale ed Applicata Ciclo XXIV Biology and conservation status of Juniperus macrocarpa Sm. in Sardinia Settore/i scientifico disciplinari di afferenza: BIO/03 Presentata da: Maria Silvia Pinna Coordinatore Dottorato: Prof. Gianluigi Bacchetta Tutor/Relatore. Prof. Gianluigi Bacchetta Co-Tutor: PhD. Eva Maria Cañadas Sánchez, PhD. Oscar Grillo, PhD. Efisio Mattana, PhD. Cristiano Pontecorvo Esame finale anno accademico 2011 – 2012 i ii “Germogli invisibili, infiniti, ben celati, Sotto la neve e il ghiaccio, sotto la tenebra, in ogni pollice quadrato o cubico, Germogli, raffinati, in delicati pezzi, microscopici, non ancora nati, Come feti nell’utero, latenti, ripiegati, compatti, dormenti, Bilioni di bilioni, trilioni di trilioni in attesa, (Sulla terra e nel mare – l’universo – lassù le stelle nei cieli) Urgono lenti e scuri,urgono verso il futuro, si formano all’infinito, E molti più, sempre più in attesa”. Walt Withman, “Germogli invisibili”, Foglie d’erba “ALBERO l'esplosione lentissima di un seme” Bruno Munari, "Fenomeni bifronti" iii SUMMARY ABSTRACT .................................................................................................................................... 1 INTRODUCTION ........................................................................................................................... 4 The Juniperus spp. habitat (2250*) ................................................................................................. 5 Taxonomic treatments ..................................................................................................................... 5 Study species ................................................................................................................................... 6 Study area ........................................................................................................................................ 8 Geological, geographical and climatic context of study areas ........................................................ 9 Threats and conservation ............................................................................................................... 10 Plan of the work ............................................................................................................................. 11 Aims ............................................................................................................................................... 12 References ...................................................................................................................................... 13 CHAPTER 1 INTER AND INTRASPECIFIC MORPHOMETRIC VARIABILITY IN JUNIPERUS L. SEEDS ................................................................................................................. 18 Abstract .......................................................................................................................................... 18 Introduction .................................................................................................................................... 18 Materials and methods ................................................................................................................... 20 Seed lot details............................................................................................................................... 20 Seed size and shape analysis........................................................................................................ 21 Statistical analysis......................................................................................................................... 24 Results............................................................................................................................................ 25 Discussion ...................................................................................................................................... 33 Acknowledgements ........................................................................................................................ 36 References ...................................................................................................................................... 36 CHAPTER 2 SEED VIABILITY AND GERMINATION PHENOLOGY IN JUNIPERUS MACROCARPA SM. ..................................................................................................................... 44 Abstract .......................................................................................................................................... 44 Introduction .................................................................................................................................... 45 Materials and methods ................................................................................................................... 47 Seed lot details..............................................................................................................................47 Germination and viability tests..................................................................................................... 47 iv Data analysis.................................................................................................................................. 48 Results ........................................................................................................................................... 48 Viability..........................................................................................................................................48 Germination................................................................................................................................... 50 Discussion ...................................................................................................................................... 53 Acknowledgements ....................................................................................................................... 57 References ..................................................................................................................................... 58 CHAPTER 3 FACTORS AFFECTING EMERGENCE, SURVIVAL AND GROWTH OF JUNIPERUS MACROCARPA SM. SEEDLINGS......................................................................... 64 Abstract .......................................................................................................................................... 64 Introduction ................................................................................................................................... 65 Materials and methods ................................................................................................................... 67 Study species and area................................................................................................................... 67 Sampling design and data collection............................................................................................. 68 Data analysis.................................................................................................................................. 68 Results ........................................................................................................................................... 70 Emergence......................................................................................................................................70 Survival...........................................................................................................................................73 Growth............................................................................................................................................76 Discussion ...................................................................................................................................... 77 Emergence......................................................................................................................................77 Survival...........................................................................................................................................79 Growth............................................................................................................................................80 Implication for recovery and conservation.................................................................................... 81 Acknowledgements ....................................................................................................................... 82 References ..................................................................................................................................... 82 CHAPTER 4 JUNIPERUS SPP. HABITAT IN COASTAL DUNES: APPROACH FOR CONSERVATION. ....................................................................................................................... 90 Abstract .......................................................................................................................................... 90 Introduction ................................................................................................................................... 91 Materials and methods ................................................................................................................... 93 Data collections...............................................................................................................................93