Synergy between habitat fragmentation and climate change: implications for biodiversity in Alpine ecosystems A thesis submitted for the degree of Doctor of Philosophy (Ph.D.) Oriana Pilia September 2011 Faculty of Natural Sciences, Division of Biology, Department of Life Sciences Silwood Park Campus, Ascot, Berkshire, SL5 7PY, U.K. “We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity” E. O. Wilson Supervisors Examiner Committee Dr Rob Ewers, Imperial College of London Prof Tim Coulson, Imperial College of London Dr Simon Leather, Imperial College of London Prof Keith Day, University of Ulster Table of contents Declaration................................................................................................................................ 5 Abstract ..................................................................................................................................... 6 Chapter I Background .................................................................................................. 8 1.1 Alps and development of conservation network ....................................................................................... 9 1.2 Fragmentation in modified alpine ecosystem ......................................................................................... 13 1.3 Global warming and prospective scenarios for the Alps ....................................................................... 18 1.4 Combined effects of habitat fragmentation and climate change on biodiversity ................................ 21 1.5 Altitudinal gradient as surrogate for changing climate ......................................................................... 24 1.6 Ground beetles and their role on environmental studies ....................................................................... 25 Chapter II Climate gradients magnify the impact of habitat fragmentation on ground beetle communities in the Italian Alps.................................................................... 28 2.1 Abstract ...................................................................................................................................................... 29 2.2 Introduction ............................................................................................................................................... 30 2.3 Methods ...................................................................................................................................................... 33 2.3.1 Study Area ......................................................................................................................................... 33 2.3.2 Experimental design and sampling of ground beetles ....................................................................... 35 2.3.3 Microclimate...................................................................................................................................... 37 2.3.4 Statistical analysis ............................................................................................................................. 37 2.4 Results ........................................................................................................................................................ 39 2.4.1 Microclimatic gradients .................................................................................................................... 39 2.4.2 Ground beetle composition ................................................................................................................ 39 2.4.3 Interactions between fragmentation and altitude .............................................................................. 43 2.5 Discussion ................................................................................................................................................... 46 2.5.1 Conclusion ......................................................................................................................................... 50 Chapter III Interacting effects of habitat fragmentation and altitude on body size and fluctuating asymmetry of Haptoderus unctulatus (Carabidae) in the Italian Alps .... 51 3.1 Abstract ............................................................................................................................................ 52 3.2 Introduction ..................................................................................................................................... 53 3.3 Material and methods ..................................................................................................................... 56 3 | 3.3.1 Study site ............................................................................................................................................ 56 3.3.2 Sampling scheme ............................................................................................................................... 57 3.3.3 Species and morphometry .................................................................................................................. 58 3.3.4 Statistical analysis ............................................................................................................................. 59 3.4 Results ............................................................................................................................................... 61 3.4.1 Preliminary analyses of asymmetry ................................................................................................... 62 3.4.2 Effects of habitat fragmentation and altitude on beetle morphology ................................................. 63 3.5 Discussion ......................................................................................................................................... 65 Chapter IV Similar life history trait combinations interact to determine species’ sensitivity to habitat fragmentation and climate change.................................................... 69 4.1 Abstract ............................................................................................................................................ 70 4.2 Introduction ..................................................................................................................................... 71 4.3 Methods ............................................................................................................................................ 74 4.3.1 Study site and sampling design .......................................................................................................... 74 4.3.2 Ground beetle functional traits .......................................................................................................... 75 4.3.3 Data analysis ..................................................................................................................................... 76 4.4 Results ............................................................................................................................................... 79 4.5 Discussion ......................................................................................................................................... 84 Chapter V Summary and prospects ............................................................................ 87 5.1 Discussion ......................................................................................................................................... 88 5.2 Future work ..................................................................................................................................... 93 References ............................................................................................................................... 95 Appendix ............................................................................................................................... 125 Acknowledgements .............................................................................................................. 131 List of figures ........................................................................................................................ 132 List of tables.......................................................................................................................... 137 4 | Declaration I hereby declare, as the author of this thesis, that material here contained is a presentation of original research work performed by me under the guidance and advice of my faculty supervisors, and has not been submitted in any form for another degree or diploma at any university or other institute. All contributions of others are involved, every effort is made to indicate this clearly in the text, with due reference to the literature. PhD student Oriana Pilia Supervisors: Rob Ewers Simon Leather 5 | Abstract An increase in global temperature accompanied by rapid fragmentation of habitats will lead to greater pressure on biodiversity, with more dramatic impacts expected on high mountain ranges. A new wave of extinction is likely to occur as the ability of species to migrate toward new cooler suitable areas will be hampered by altered landscapes, also the magnitude of species loss will in part depend on species traits, or phenotypic plasticity of individuals which will have to adapt to the changed environmental conditions. In this PhD thesis, I included different