University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2014 Comparative Demography and Life history Evolution of Plants Mbeau ache, Cyril http://hdl.handle.net/10026.1/3201 Plymouth University All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. Copyright Statement This copy of the thesis has been supplied on the condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author’s prior consent. Title page Comparative Demography and Life history Evolution of Plants By Cyril Mbeau ache (10030310) A thesis submitted to Plymouth University in partial fulfillment for the degree of DOCTOR OF PHILOSOPHY School of Biological Sciences Plymouth University, UK August 2014 ii Comparative demography and life history evolution of plants Cyril Mbeau ache Abstract Explaining the origin and maintenance of biodiversity is a central goal in ecology and evolutionary biology. Some of the most important, theoretical explanations for this diversity centre on the evolution of life histories. Comparative studies on life history evolution, have received significant attention in the zoological literature, but have lagged in plants. Recent developments, however, have emphasised the value of comparative analysis of data for many species to test existing theories of life history evolution, as well as to provide the basis for developing additional or alternative theories. The primary goal of this study was to explore existing theories of life history evolution using a dataset of demographic information in the form of matrix population models for a large number of plant species. By projecting average matrix population models for 207 plant species, life tables and fecundity schedules were obtained and, in turn, were used to estimate relevant life history parameters. These parameters were then used to explore the i) lability of life history traits in plants ii) their continuum of life history variation, iii) the evolution of senescence and iv) the significance of demographic entropy in population ecology. Elasticities and sensitivities of life history traits showed significant phylogenetic signal compared to other life history traits, although, all the values of phylogenetic signal observed were < 1 indicating that life history traits are generally labile. Eighty one percent of species in the datset had mortality curves that increased with age compared to one hundred percent of species that showed a reproductive value curve that decreases with age at the end of life. In particular, the parameters that measured pace and duration were inversely related suggesting in general, the presence of senescence in our data set. Finally, the tenets of the directionality theory based on demographic entropy were generally not confirmed. This study provides an important contribution to the life history evolution of iteroparous perennial plants and confirms existing theories on life history evolution. iii Table of Content Copyright Statement ........................................................................................................ i Title page ....................................................................................................................... ii Abstract ......................................................................................................................... iii Table of Content ............................................................................................................ iv List of Tables ................................................................................................................. vi List of Figures .............................................................................................................. viii Dedication..................................................................................................................... xi Acknowledgements ......................................................................................................... xii List of Publications ........................................................................................................ xiv Oral presentations ......................................................................................................... xv Workshops and poster presentations ................................................................................ xv Skilled courses attended with dates .................................................................................. xvi Author’s declaration ..................................................................................................... xvii Thesis outline ............................................................................................................. xviii Chapter 1: Introduction ................................................................................................... 1 1.0 General introduction .............................................................................................. 2 1.1 Database .......................................................................................................... 4 1.2 Limitation of the dataset .......................................................................................... 6 Chapter 2: General Methodology ...................................................................................... 9 2.0: Matrix Population Models .................................................................................... 10 2.1: Transition Matrix Analysis ................................................................................... 14 2.2: Non Phylogenetic Comparative Method ................................................................. 15 2.3: Phylogenetic Comparative Method ........................................................................ 16 2.4: Comparative Analysis of Demography and Life History Dataset ............................... 18 Chapter 3: Phylogenetic Signal in the Demography of Iteroparopus Perennial Plants............ 20 3.0 Abstract .............................................................................................................. 21 3.1: Introduction ........................................................................................................ 22 3.2: Material and Methods .......................................................................................... 25 3.2.1: Data Analysis ............................................................................................... 26 3.3: Results ............................................................................................................... 29 3.4: Discussion .......................................................................................................... 34 3.4.1: Comparison of Methods ................................................................................. 34 3.4.2: Phylogenetic Signal in Demographic Life History Traits. ...................................... 35 Chapter 4: Evolution of Senescence in Iteroparous Perennial Plants ................................... 40 4.0 Abstract .............................................................................................................. 41 iv 4.1: Introduction ........................................................................................................ 42 4.2: Material and Methods .......................................................................................... 45 4.3: Results ............................................................................................................... 46 4.3.1: Age Specific Mortality ................................................................................... 46 4.3.2: Age Specific Reproductive Value ..................................................................... 48 4.4: Discussion .......................................................................................................... 50 4.5: Conclusion ......................................................................................................... 53 Chapter 5: The Time Distribution of Reproductive Value Measures the Pace of Life .............. 55 5.0 Abstract .............................................................................................................. 56 5.1: Introduction ........................................................................................................ 57 5.2: Material and Methods .......................................................................................... 59 5.2.1: A Biological Meaniful Time Distribution .......................................................... 59 5.2.2: Plant Demography Data and Population Projection .......................................... 62 5.2.3: Data Analyses ............................................................................................... 62 5.3: Results ............................................................................................................... 63 5.3.1: Model Fit ....................................................................................................