Biology Department Research Group Terrestrial Ecology _____________________________________________________________________________________ THE IMPORTANCE OF VEGETATION CONFIGURATION IN COASTAL DUNES TO PRESERVE DIVERSITY OF MARRAM- ASSOCIATED INVERTEBRATES IS HABITAT CONFIGURATION A DRIVER OF DIVERSITY IN DUNES? Noëmie Van den Bon Studentnumber: 01506438 Supervisor(s): Prof. Dr. Dries Bonte Dr. Martijn Vandegehuchte Scientific tutor: Ruben Van De Walle Master’s dissertation submitted to obtain the degree of Master of Science in Biology Academic year: 2019 - 2020 © Faculty of Sciences – research group Terrestrial Ecology All rights reserved. This thesis contains confidential information and confidential research results that are property to the UGent. The contents of this master thesis may under no circumstances be made public, nor complete or partial, without the explicit and preceding permission of the UGent representative, i.e. the supervisor. The thesis may under no circumstances be copied or duplicated in any form, unless permission granted in written form. Any violation of the confidential nature of this thesis may impose irreparable damage to the UGent. In case of a dispute that may arise within the context of this declaration, the Judicial Court of Gent only is competent to be notified. 2 Table of content 1. Introduction ....................................................................................................................................... 5 1.1. The status of biodiversity and ecosystems ........................................................................................... 5 1.2. Ecological concepts in species distribution and ecological communities .............................................. 5 1.3. Habitat configuration as driver of diversity in ecological communities ................................................ 6 1.4. Nature conservation ............................................................................................................................. 7 1.5. Marram dunes as model-system to assess the influence of habitat configuration on diversity ........... 8 1.6. The invertebrate fauna of marram dunes ............................................................................................ 9 2. Objectives ......................................................................................................................................... 11 2.1. Hypothesis 1 ....................................................................................................................................... 11 2.2. Hypothesis 2 ....................................................................................................................................... 12 2.3. Hypothesis 3 ....................................................................................................................................... 12 3. Material and methods ....................................................................................................................... 13 3.1. Study area .......................................................................................................................................... 13 3.2. Data collection .................................................................................................................................... 14 3.3. Marram grass properties .................................................................................................................... 15 3.4. Spatial configuration of marram grass around the sampling sites .................................................... 15 3.5. Species identification .......................................................................................................................... 17 3.6. Data analyses ..................................................................................................................................... 17 4. Results .............................................................................................................................................. 20 4.1. Data exploration ................................................................................................................................. 20 4.2. Models for the local environmental variables .................................................................................... 23 4.2.1. The influence of the spatial configuration on marram inflorescences ........................................ 24 4.2.2. The influence of the spatial configuration on marram vitality .................................................... 25 4.2.3. The influence of the spatial configuration on marram height ..................................................... 25 4.3. Models for habitat specialisation ....................................................................................................... 26 4.3.1. The influence of the spatial configuration of marram grass on general invertebrate diversity .. 27 4.3.2. The influence of the spatial configuration of marram grass on dune-specific invertebrate diversity ................................................................................................................................................. 30 4.3.3. The influence of the spatial configuration of marram grass on marram-specific invertebrate diversity ................................................................................................................................................. 33 5. Discussion ......................................................................................................................................... 38 5.1. A dynamic environment for higher quality marram grass .................................................................. 38 5.2. Does the species-area relationship hold in the stabilisation of dunes? .............................................. 39 3 5.3. Does high-quality marram grass benefit marram-specific invertebrate species? .............................. 40 5.4. Does the response to spatial configuration depend on habitat specialisation? ................................. 41 5.5. Additional observations and findings ................................................................................................. 42 5.6. Importance and implications of the results ........................................................................................ 42 5.7. How do we proceed? .......................................................................................................................... 43 6. Conclusion ......................................................................................................................................... 45 7. Summaries ........................................................................................................................................ 46 7.1 English summary ................................................................................................................................. 46 7.2. Nederlandstalige samenvatting ......................................................................................................... 49 7.3. Laymen summary ............................................................................................................................... 51 8. Acknowledgement ............................................................................................................................ 52 9. References ........................................................................................................................................ 53 10. Appendix ......................................................................................................................................... 59 10.1. Classification ................................................................................................................................. 59 10.2. Output of models .............................................................................................................................. 72 10.2.1. Models for the local environmental variables ........................................................................... 72 10.2.2. Models for diversity (France, Belgium and the United Kingdom) .............................................. 73 10.2.2.1. Models for general diversity ............................................................................................... 73 10.2.2.2. Models for dune-specific diversity ...................................................................................... 74 10.2.2.3. Models for marram-specific diversity ................................................................................. 75 10.2.3. Models for diversity (France and Belgium) ................................................................................ 76 10.2.3.1. Models for general diversity ............................................................................................... 76 10.2.3.2. Models for dune-specific diversity ...................................................................................... 79 10.2.3.3. Models for marram-specific diversity ................................................................................. 81 10.3. R-code ............................................................................................................................................... 84 4 1. Introduction 1.1. The status of biodiversity and ecosystems Humanity is altering the biosphere across all