Species Distributions and Climate Change:Current Patterns and Future Scenarios for Biodiversity
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Species distributions and climate change:current patterns and future scenarios for biodiversity Hof, Christian Publication date: 2010 Document version Publisher's PDF, also known as Version of record Citation for published version (APA): Hof, C. (2010). Species distributions and climate change:current patterns and future scenarios for biodiversity. Museum Tusculanum. Download date: 05. Oct. 2021 DEPARTMENT OF BIOLOGY FACULTY OF SCIENCE UNIVERSITY OF COPENHAGEN Species distributions and climate change: current patterns and future scenarios for biodiversity A dissertation submitted to the University of Copenhagen in accordance with the requirements of the degree of PhD at the Faculty of Science, Department of Biology, to be defended publicly before a panel of examiners by Christian Hof February 2010 Supervised by Prof. Dr. Carsten Rahbek and Prof. Dr. Miguel B. Araújo “It is now clear that climate change is the major new threat that will confront biodiversity this century.” Lovejoy & Hannah 2005 Preface This thesis is the result of a three-year PhD project which was jointly based at the Center for Macroecology, Evolution and Climate, Department of Biology, University of Copenhagen (Denmark) and the Biodiversity and Global Change Lab, Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences (CSIC), Madrid (Spain). The project was jointly supervised by Prof. Dr. Carsten Rahbek (Copenhagen) and Prof. Dr. Miguel B. Araújo (Madrid). The PhD project was temporally split into two equal parts performed at the two work places mentioned above. The project was funded by an internationalization stipend from the Danish Agency for Science, Technology and Innovation, administered by the University of Copenhagen. The thesis consists of two parts. The first part is a synopsis which gives an overview of the background and the objectives of the thesis, summarizes and discusses the main findings, and outlines some perspectives for future research. The second part consists of five manuscripts, written as scientific papers, which comprise the core work of the PhD project. Finally, three supplementary chapters document some additional work on topics related to the objectives of the thesis. Christian Hof Copenhagen, February 2010 Contents Summary ...................................................................................................................... 9 Resumé ........................................................................................................................ 11 Zusammenfassung................................................................................................... 13 PART 1 Synopsis ....................................................................................................................... 15 1. Introduction ....................................................................................................... 17 1.1 Species distributions and climate change ................................................... 17 1.2 The temporal stability of the climatic niche ............................................... 18 1.3 Dispersal and habitat stability..................................................................... 19 1.4 Objectives of the thesis............................................................................... 20 2. Summary and discussion of main findings ..................................................... 20 2.1 Potential impacts of climate change and its interactions with other threats on biodiversity............................................................................................ 20 2.2 Phylogenetic signal in climatic niche similarity......................................... 23 2.3 The influence of habitat stability on dispersal ability: Spatial patterns of freshwater diversity and the equilibrium of species distributions with contemporary climate ................................................................................. 25 3. Perspectives........................................................................................................ 27 3.2 Habitats, dispersal and climate change....................................................... 29 3.3 Ecological niches: What are we measuring? .............................................. 30 3.4 Interaction of different threats: challenges for conservation...................... 31 References................................................................................................................ 32 Acknowledgements.................................................................................................. 43 PART 2 Chapter I...................................................................................................................... 49 Rethinking species’ ability to cope with rapid climate change Chapter II.................................................................................................................... 57 Future threats for global amphibian diversity Chapter III.................................................................................................................. 97 Phylogenetic signals in the climatic niches of the world’s amphibians Chapter IV ................................................................................................................ 125 Habitat availability cannot explain the species richness patterns of European lentic and lotic freshwater animals Chapter V .................................................................................................................. 149 The effect of habitat stability on dispersal and species’ ability to track climate change APPENDIX Supplementary chapter A ..................................................................................... 171 Latitudinal variation of diversity in European freshwater animals is not concordant across habitat types Supplementary chapter B ..................................................................................... 181 Partitioning and mapping uncertainties in ensembles of forecasts of species turnover under climate change Supplementary chapter C ..................................................................................... 193 Range size patterns in European freshwater trematodes Curriculum vitae.................................................................................................... 217 9 Summary How does climate change affect biodiversity? – Answering this question is one of the most important tasks in current ecological research. Earth has been warming by 0.7°C during the last 100 years, and the consequences are already apparent in biotic systems. For example, species are responding by shifts of their distributional ranges, which affects the spatial patterns of species richness and turnover. Global temperatures are projected to rise by 1.8 - 4°C until the end of the century; hence climate change will most likely leave further imprints on species and ecosystems. This PhD thesis aims to contribute to a better understanding of the impacts of climate change on species distributions and spatial patterns of biodiversity. Contemporary climate change is assumed to be one of the major future threats for biodiversity, due to its supposedly unprecedented velocity. On the contrary, recent studies suggest that climatic changes during and after the Pleistocene may have been much faster than commonly assumed. In one of the studies of this thesis I discuss the consequences of these findings for species and ecosystems. Since these rapid climate change events did not cause a broad-spectrum mass extinction, one might assume that most species may also be able to successfully cope with contemporary climate change. However, current ecosystems are heavily modified by humans. Among other factors, habitat destruction and fragmentation caused by anthropogenic land-use changes negatively affect species’ strategies to cope with climate change. Therefore, although we need to rethink species’ abilities to cope with rapid climate change, the interactions of different threats impose severe challenges for biodiversity. In a global assessment of future threats for amphibian diversity, I investigate the geography of climate change, land-use change and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Results indicated that the regions with highest projected climate and land-use change impacts show a strong tendency of congruence, but show little overlap with regions of high Bd prevalence. Overall, two-thirds of the areas harboring the richest amphibian faunas may be heavily impacted by at least one of the major threats by 2080. The stability of the climatic niche influences the need for a species to track climate change via dispersal, or its potential to adapt to novel climatic conditions. I therefore explore the phylogenetic signal in climatic niches of the world’s amphibians, which serves as a surrogate quantification of niche stability. Results indicate an overall tendency of phylogenetic signal to be present in realised climatic niches, but signal strength varies across biogeographical regions and among amphibian orders. The ability to successfully track climatic changes depends on dispersal, which is in turn influenced by ecological adaptations, such as the affiliation with a certain habitat type. A common hypothesis is that species adapted to less persistent habitats have evolved stronger dispersal abilities. Two studies of my thesis provide evidence for this hypothesis: (1) geographical distributions of dragonflies adapted