Vegetation and functional diversity of sand dune habitats between and within different bioclimatic regions Dissertation for the award of the degree "Doctor of Philosophy" Ph.D. Division of Mathematics and Natural Sciences of the Georg-August-Universität Göttingen within the doctoral program Biology of the Georg-August University School of Science (GAUSS) submitted by Parastoo Mahdavi from Esfahan, Iran Göttingen, 2017 Thesis Committee Prof. Dr. E. Bergmeier, Abt. Vegetationsanalyse & Phytodiversität, Georg-August-Universität Göttingen Prof. Dr. C. Leuschner, Abt. Ökologie & Ökosystemforschung, Georg-August-Universität Göttingen Members of the Examination Board Reviewer: Prof. Dr. E. Bergmeier, Abt. Vegetationsanalyse & Phytodiversität, Georg-August- Universität Göttingen Second reviewer: Prof. Dr. C. Leuschner, Abt. Ökologie & Ökosystemforschung, Georg- August-Universität Göttingen Further members of the Examination Board: Prof. Dr. H. Behling, Abt. Palynologie und Klimadynamik, Georg-August-Universität Göttingen Prof. Dr. T. Friedl, Abt. Experimentelle Phykologie und Sammlung von Algenkulturen der Universität Göttingen (EPSAG), Georg-August-Universität Göttingen PD. Dr. M. Waltert, Blumenbach Institute for Zoology and Anthropology, Conservation Biology/Workgroup on Endangered Species, Georg-August-Universität Göttingen Prof. Dr. H. Kreft, Abt. Biodiversität, Makroökologie und Biogeographie, Georg-August- Universität Göttingen Date of the oral examiniation: 26.4.2017 “It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.” Charles Darwin a b c d e View of the main habitats occurring in sand ecosystems: a. driftline; b. mobile dune; c. e stabilized dune; d. dune slack; e. salt marsh. Contents Summary ............................................................................................................................................... 1 Zusammenfassung ............................................................................................................................... 3 Chapter 1 Introduction ..................................................................................................................... 5 Sand dune ecosystem ............................................................................................................................... 7 Ecosystem features ............................................................................................................................... 7 Habitat diversity and survival strategies .............................................................................................. 8 Adaptive traits of plants as a key to understanding ecosystem function ................................................ 11 Concept and definition of functional traits ......................................................................................... 11 Ecological values of the functional approach..................................................................................... 12 C4 photosynthesis, a complex trait ........................................................................................................ 14 Diversity of photosynthetic types ....................................................................................................... 14 Evolutionary pressure ......................................................................................................................... 15 Origin and diversity of C4 plants ....................................................................................................... 15 Study area ............................................................................................................................................... 17 Irano-Turanian region ........................................................................................................................ 17 Hyrcanian region ................................................................................................................................ 18 Mediterranean region ......................................................................................................................... 18 Atlantic region .................................................................................................................................... 18 General description of methods .............................................................................................................. 19 Data collection ................................................................................................................................... 19 Data analysis ...................................................................................................................................... 20 Objectives and thesis outline .................................................................................................................. 20 References .............................................................................................................................................. 23 Chapter 2 Plant functional traits and diversity in sand dune ecosystems across different biogeographic regions ....................................................................................................................... 35 Abstract .................................................................................................................................................. 37 Introduction ............................................................................................................................................ 37 Study area ............................................................................................................................................... 39 Methods .................................................................................................................................................. 40 Data collection ................................................................................................................................... 40 Data analysis ...................................................................................................................................... 41 Results .................................................................................................................................................... 43 Floristic diversity ............................................................................................................................... 43 Cluster analysis of functional traits .................................................................................................... 43 Trait distribution across habitats ........................................................................................................ 46 Trait distribution across regions ......................................................................................................... 48 Community weighted trait means ...................................................................................................... 49 Discussion .............................................................................................................................................. 49 Functional groups across different regions ........................................................................................ 49 Functional traits and habitat types ...................................................................................................... 51 Conclusions ............................................................................................................................................ 52 References .............................................................................................................................................. 53 Chapter 3 Sand habitats across biogeographical regions at species, community and functional level ................................................................................................................................... 59 Abstract .................................................................................................................................................. 61 Introduction ............................................................................................................................................ 61 Study areas ............................................................................................................................................. 61 Methods .................................................................................................................................................. 64 Data collection ................................................................................................................................... 64 Data analysis ...................................................................................................................................... 65 Results .................................................................................................................................................... 66 Taxonomic diversity and similarity .................................................................................................... 66 Syntaxonomic diversity and similarity ............................................................................................... 69 Functional diversity and similarity ....................................................................................................