ZENTRUM FÜR BIODIVERSITÄT UND NACHHALTIGE LANDNUTZUNG SEKTION BIODIVERSITÄT, ÖKOLOGIE UND NATURSCHUTZ − CENTRE OF BIODIVERSITY AND SUSTAINABLE LAND USE − SECTION: BIODIVERSITY, ECOLOGY AND NATURE CONSERVATION Assembly processes in soil animal communities: Integrating phylogeny and trait-based approaches Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultäten der Georg-August-Universität Göttingen vorgelegt von Master of Science Ting-Wen Chen aus Kaohsiung City, Taiwan Göttingen, Dezember 2017 Referent: Prof. Dr. Stefan Scheu Korreferent: Prof. Dr. Holger Kreft Tag der mündlichen Prüfung: 26.01.2018 Nothing in biology makes sense except in the light of evolution. Theodosius Dobzhansky Table of contents Summary .......................................................................................................................1 Chapter 1 General Introduction ....................................................................................................3 The nature of soil biodiversity .........................................................................................................................3 Inferring processes from patterns ...................................................................................................................3 Community assembly processes ......................................................................................................................................3 Functional traits—the objects ..........................................................................................................................................4 Community phylogenetic patterns ...................................................................................................................................5 A conceptual model for soil biodiversity studies ............................................................................................6 Collembola—the model organisms .................................................................................................................7 Collembola phylogeny .....................................................................................................................................................8 Collembola traits ..............................................................................................................................................................9 Fatty acid composition as a trait ......................................................................................................................................9 Case studies using Collembola ......................................................................................................................................10 Structure of the thesis .....................................................................................................................................11 References ........................................................................................................................................................11 Chapter 2 Collembola Phylogeny and Trait Evolution .............................................................17 Abstract ...........................................................................................................................................................17 Keywords .........................................................................................................................................................17 Introduction..................................................................................................................................................... 18 Materials and Methods ..................................................................................................................................19 Taxa sampling ...............................................................................................................................................................19 DNA extraction, PCR and sequencing ...........................................................................................................................20 Phylogeny of field-collected Collembola ......................................................................................................................21 Individual-based unrooted phylogeny .....................................................................................................................21 Species-based phylogeny......................................................................................................................................... 21 Extended Collembola phylogeny ...................................................................................................................................22 Ultrametric tree transformation .....................................................................................................................................22 Collembola traits ............................................................................................................................................................23 Phylogenetic signal ........................................................................................................................................................23 Ancestral state estimation ..............................................................................................................................................24 Evolution model of traits ...............................................................................................................................................24 Correlated evolution of traits .........................................................................................................................................24 Results ..............................................................................................................................................................25 Phylogeny of field-collected Collembola ......................................................................................................................25 Phylogeny of species occurring in Central Europe ........................................................................................................25 Phylogenetic signal of traits ...........................................................................................................................................28 Trait evolution ................................................................................................................................................................28 Discussion ........................................................................................................................................................32 Collembola phylogeny ...................................................................................................................................................32 Functional traits and their evolution ..............................................................................................................................33 Conclusions and Outlooks ............................................................................................................................................35 Author Contributions .....................................................................................................................................35 Data Accessibility ............................................................................................................................................35 References ........................................................................................................................................................35 Supplementary Materials ...............................................................................................................................41 vii Chapter 3 Neutral lipid fatty acid composition as trait and constraint in Collembola evolution ......................................................................................................................59 Abstract ...........................................................................................................................................................59 Keywords .........................................................................................................................................................59 Introduction..................................................................................................................................................... 60 Materials and Methods ..................................................................................................................................61 Sampling .......................................................................................................................................................................61 Fatty acid analysis ..........................................................................................................................................................63 Collembola phylogeny ...................................................................................................................................................64 Statistical analysis ..........................................................................................................................................................65