Ant Diversity, Function and Services Across
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ANT DIVERSITY, FUNCTION AND SERVICES ACROSS TROPICAL LAND-USE SYSTEMS IN INDONESIA 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: Biodiversity and Ecology submitted by M.Sc. Lisa Helen Denmead from Blenheim (New Zealand) Göttingen, 2016 Thesis Committee Prof. Dr. Teja Tscharntke (Dept. Crop Sciences / Agroecology) Prof. Dr. Stefan Vidal (Dept. of Crop Sciences / Agroentomology) Prof. Dr. Kerstin Wiegand (Dept. of Ecosystem Modelling/ A.-v.-H. Institute for Plant Sciences) Members of the Examination Board Prof. Dr. Teja Tscharntke (Dept. Crop Sciences / Agroecology) Prof. Dr. Stefan Vidal (Dept. of Crop Sciences / Agroentomology) Prof. Dr. Kerstin Wiegand (Dept. of Ecosystem Modelling/ A.-v.-H. Institute for Plant Sciences) Dr Yann Clough (Dept. Crop Sciences / Agroecology and Centre for Environmental and Climate Research, Lund University) Prof. Dr. Holger Kreft (Free Floater Research Group – Biodiversity, Macroecology & Conservation Biogeography Group) Prof. Dr Hermann Behling (Dept. of Palynology and Climate Dynamics) Date of the oral examination: 17.03.2016 Table of contents Summary .................................................................................................................................... 1 Chapter 1: General Introduction ................................................................................................. 3 1.1 Land-use change in the tropics ........................................................................................ 4 1.2 Consequences of land-use change on biodiversity and ecosystem functioning .............. 5 1.3 Potential factors influencing maintenance of biodiversity and ecosystem functions in land-use systems .................................................................................................................... 6 1.4 The role of ants in ecosystems ......................................................................................... 8 1.5 Project framework (EFForTs) .......................................................................................... 8 1.6 Thesis objectives .............................................................................................................. 9 Chapter 2: Agricultural land use alters species composition but not species richness of ant communities ............................................................................................................................. 13 2.1 Introduction ................................................................................................................... 14 2.2 Materials and methods ................................................................................................... 14 2.3 Results ........................................................................................................................... 16 2.4 Discussion ...................................................................................................................... 20 2.5 Supplementary material ................................................................................................. 22 Chapter 3: Single- and multi-trait measures reveal widespread functional diversity loss in human-modified tropical landscapes ........................................................................................ 27 3.1 Introduction ................................................................................................................... 28 3.2 Materials and Methods .................................................................................................. 29 3.3 Results ........................................................................................................................... 33 3.4 Discussion ...................................................................................................................... 36 3.5 Supplementary material ................................................................................................. 40 Chapter 4: Local and landscape drivers of arthropod diversity and decomposition processes in oil palm leaf axils ..................................................................................................................... 51 4.1 Introduction ................................................................................................................... 52 4.2 Materials and methods ................................................................................................... 53 4.3 Results ........................................................................................................................... 56 4.4 Discussion ...................................................................................................................... 60 4.5 Supplementary material ................................................................................................. 63 Chapter 5: Biological control in oil palm is enhanced by landscape context ........................... 73 5.1 Introduction ................................................................................................................... 74 5.2 Materials and methods .................................................................................................. 75 5.3 Results ........................................................................................................................... 79 5.4 Discussion ..................................................................................................................... 82 5.4 Supplementary material ................................................................................................. 85 Chapter 6: Ants affect belowground invertebrate communities and associated functions across tropical land-use systems ......................................................................................................... 95 6.1 Introduction ................................................................................................................... 96 6.2 Materials and methods .................................................................................................. 97 6.3 Results ......................................................................................................................... 100 6.4 Discussion ................................................................................................................... 108 6.5 Supplementary material ............................................................................................... 112 Chapter 7: The role of ants, birds and bats for ecosystem functions and services in oil palm plantations ............................................................................................................................ 123 7.1 Introduction ................................................................................................................. 124 7.2 Materials and methods ................................................................................................ 125 7.3 Results ......................................................................................................................... 131 7.4 Discussion ................................................................................................................... 134 7.5 Supplementary material ............................................................................................... 137 Chapter 8: Synthesis................................................................................................................ 151 8.1 Objective 1: Understand ant taxonomic and functional diversity responses to land-use change ............................................................................................................................. 151 8.2 Objective 2: Investigate the response of ant communities and associated functions to landscape context and local management in oil palm plantations..................................... 152 8.3 Objective 3: Examine the role of ant communities in shaping arthropod communities and associated ecosystem functions and services .................................................................... 153 8.4 Overall conclusions ..................................................................................................... 154 Bibliography............................................................................................................................ 157 Acknowledgements ................................................................................................................. 171 Declaration .............................................................................................................................. 173 Curriculum Vitae..................................................................................................................... 175 Publication list......................................................................................................................... 177 Summary Land-use change due to agricultural expansion is one of the greatest global threats to biodiversity and associated ecosystem functions and services. In the tropics in particular, conversion of forest and agroforests into monoculture agriculture such as oil palm is happening at an extremely rapid rate, leading to highly simplified landscapes. In Indonesia, currently the world’s leading palm oil producer,