Carbon Storage and Floristic Dynamics in Peruvian Peatland Ecosystems

Carbon storage and floristic dynamics in Peruvian peatland ecosystems Frederick Charles Henry Draper Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Geography September 2015 i The candidate confirms that the work submitted is his own, except where work which has formed part of jointly authored publications has been included. The contribution of the candidate and the other authors to this work has been explicitly indicated below. The candidate confirms that appropriate credit has been given within the thesis where reference has been made to the work of others. Chapter 2: Draper, F.C., Roucoux, K.H., Lawson, I.T., Mitchard, E.T.A., Honorio Coronado, E.N., Lähteenoja, O., Torres Montenegro, L., Valderrama Sandoval, E., Zaráte, R., Baker, T.R.. (2014). The distribution and amount of carbon in the largest peatland complex in Amazonia. Environmental Research Letters, 9. FCD, TRB, KHR,ITL and ETAM, designed the study; FCD, ENHC, OL, LTM, EVS collected data; ENHC EVS and RZ provided data; FCD analysed data and wrote the paper. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. Assertion of moral rights: The right of Frederick Draper to be identified as Author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988. © 2015 The University of Leeds and Frederick Draper ii Acknowledgements First, many thanks to my supervisors Katy Roucoux and Tim Baker for their continued support, guidance and encouragement throughout this project. I’d also like to thank my third supervisor Ian Lawson for his many valuable contributions, particularly his guidance in bringing the thesis together. I would like to extend this thanks to Ed Mitchard, who supervised the remote sensing aspects of the project and provided useful guidance particularly in the preparation of Chapter Two for publication. I would especially like to thank my field team Luis Torres, Julio Irarica, Hugo Vasques, Elvis Valderrama, Carlos Mogollon and Frans Ramirez and field assistants Sarah Pearl, Oliver Clark and Esme Shattock. Without their help in some exceptionally challenging environments this project could not have been completed. I’d like to extend this thanks to staff at IIAP including Ricardo Faroñay, Jhon del Aguila Pasquel and Dennis del Castillo Torres for their logistically support in Peru. I would also like to thank Euridice Honorio Conorado, who provided guidance throughout the project, but also provided a lot of unpublished forest plot data that were crucial to this project. I also thank Outi Lähteenoja for making her peat data available and contributing to the manuscript of Chapter Two. Paul Fine, Nigel Pitman and Oliver Phillips generously provided floristic plot data for upland forests and Chris Baraloto and Ricardo Zaraté provided plot coordinates which were used in the remote sensing classification. I would like to thank the Lab staff in the School of Geography, especially Martin Gilpin, Rachel Gasior and David Ashley who were exceptionally helpful in their assistance with soil and pollen analysis. I would also like to thank Gabriela López-González and Georgia Pickavance who provided assistance with the ForestPlots.net database. Duncan Quincey taught me the fundamentals of remote sensing and I thank him for his early input. Many people in Leeds deserve a special mention; Greta Dargie, Tom Kelly and Fernanda Coelho de Souza in particular were a sounding board for ideas and provided useful input throughout the project. Dylan Young, Adriane Esquivel Muelbert and Martin Sullivan were a iii great help with statistical analysis and coding in R and William James provided help with GIS issues. I would like to acknowledge NERC for funding my studentship (NE/J50001X/1).and for additionally funding two radiocarbon grants. Additional funding from the Quaternary Research Association, the Earth and Space Foundation, the Anglo Peruvian Society and the Royal Geographical Society contributed to fieldwork costs. iv Abstract In this thesis I took a novel interdisciplinary approach involving remote sensing, ecological and palaeoecological techniques to address some of the most fundamental gaps in our understanding of Peruvian peatlands. The existence of these peatlands was only recently confirmed and although they were known to store large quantities of carbon, initial assessments of carbon stocks were highly uncertain. In addition, little was known of their biodiversity or how they have developed. Firstly, I used data fusion remote sensing and extensive field data to generate a high resolution, landscape scale map of peatland ecosystems in the largest peatland complex in Amazonia. This approach confirmed that peatland ecosystems in northern Peru are the most carbon dense ecosystems in Amazonia storing up to 1391 ± 710 Mg C ha-1, and have a total carbon stock of 3.14 (0.44–8.15) Pg C, which equates to nearly 50 % of the total above-ground carbon stocks of the whole country. Secondly, I established a new network of floristic inventory plots and described the composition and diversity of peatland tree communities. I demonstrated that peatland pole forest has the lowest alpha diversity of all tree communities in lowland Amazonia. In contrast, by comparing these data with three larger plot networks from other ecosystems in the region, I also showed that they have surprisingly high beta diversity, and harbour important populations of species that were previously thought to be restricted to other habitat types such as white sand forest. Finally, pollen analysis was undertaken across eight peat cores from two sites to test the significance of historical processes in determining current patterns of composition and diversity. Both autogenic (internal biotic) and allogenic (external environmental) processes operating through time were important determinants of current floristic patterns. Demonstrating that such historical processes have an important role in determining the composition of tropical ecosystems is valuable as they are often overlooked – or in many cases impossible to study in such detail. v Overall this thesis shows that peatland ecosystems in the Peruvian Amazon have high conservation value both as a carbon store and for regional ecosystem diversity. In addition, peatland ecosystems provide an exciting opportunity to investigate the importance of fundamental historical and ecological processes for determining the composition and diversity of tropical forests. vi Table of Contents Acknowledgements iii Abstract v List of Figures xi List of Tables xiii 1. Introduction 1 1.1 Thesis background 1 1.1.1 Thesis outline 3 1.2 Study region 4 1.3 Peatlands in the PMFB 7 1.4 Carbon storage 8 1.4.1 Carbon storage of tropical forests 8 1.4.2 Methods for determining tropical forest carbon stock 10 1.4.3 Carbon storage of tropical peatlands 11 1.4.4 Methods for estimating peatland carbon storage 14 1.5 Floristic composition and diversity 21 1.5.1 Floristic composition and diversity of tropical forests 21 1.5.2 Measuring alpha diversity 22 1.5.3 Measuring beta diversity 24 1.5.4 Determinants of diversity and composition 26 1.5.5 Floristic composition and diversity of tropical peatlands 31 1.5.6 Floristic composition and diversity of Amazonian wetlands 32 1.5.7 Floristic composition and diversity in Northwest Amazonia 34 1.6 Long term ecosystem dynamics 35 1.6.1 Succession and development in peatlands 36 1.6.2 Succession and development in tropical peatlands 38 1.6.3 Pollen analysis in Amazonia 40 1.6.4 Linking palaeoecology and ecology 44 1.8 Thesis aims and objectives 46 1.7 Thesis approach 48 2. The distribution and amount of carbon in the largest peatland complex in Amazonia 49 2.1 Abstract 49 2.2 Introduction 50 2.3 Methods 53 2.3.1 Study area and field data 53 vii 2.3.2 Ground reference data 54 2.3.2 Satellite imagery 56 2.3.3 Image classifications 57 2.3.4 Above-ground carbon measurements 60 2.3.5 Below-ground carbon measurements 60 2.3.6. Carbon stock calculations 61 2.3.7 Sensitivity Analysis 62 2.4. Results 62 2.4.1. Carbon stock of the PMFB 62 2.4.2 Distribution of peatland ecosystem types 66 2.4.3 Performance of remote sensing classification 67 2.5. Discussion 69 2.5.1. Carbon stock of the peatlands of the PMFB 69 2.5.2 Sources of uncertainty 70 2.5.3 The role of multiple remote sensing products 72 2.5.4 Distribution of peatland ecosystem types 72 2.5.5 Contribution of PMFB to the tropical peatland carbon pool 73 2.5.6 Conclusions 74 3 Floristic composition and diversity of lowland peatland ecosystems in Northern Peru 75 3.1 Abstract 75 3.2 Introduction 76 3.3 Materials and Methods 79 3.3.1 Forest inventories 79 3.3.2. Taxonomic standardisation 81 3.3.3 Community diversity analysis 82 3.3.4 Community similarity analysis 83 3.3.5 Geographic distance and community similarity 84 3.3.6 Null Models 84 3.3.7 Criteria for defining ecological guilds 85 3.4. Results 85 3.4.1 Species richness and diversity 85 3.4.2 Floristic similarity within ecosystem types 87 3.4.3 Floristic similarity and geographic distance 88 3.4.4 Floristic similarity amongst ecosystem types 89 3.4.5. Associations between peatlands and uplands 90 3.5. Discussion 93 viii 3.5.1. Diversity of peatland forests 93 3.5.4 β-diversity amongst peatlands and surrounding uplands 96 3.5.3 β- diversity within peatland ecosystems 97 3.5.2 Endemism in peatlands 99 3.5.5 Conservation importance of peatland

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