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The Role of Humans, Climate and Vegetation in the Complex Fire Regimes of North-East Namibia

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The Role of Humans, Climate and Vegetation in the Complex Fire Regimes of North-East Namibia The role of humans, climate and vegetation in the complex fire regimes of north-east Namibia Glynis Humphrey Thesis Presented for the Degree of UniversityDoctor ofof Philosophy Cape Town in the Department of Biological Sciences University of Cape town July 2018 1 The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town Declaration I, hereby declare that the work on which this dissertation/thesis is based is my original work (except where acknowledgements indicate otherwise) and that neither the whole work nor any part of it has been, is being, or is to be submitted for another degree in this or any other university. I empower the university to reproduce for the purpose of research either the whole or any portion of the contents in any manner whatsoever. Glynis Humphrey (22nd July 2018) 2 Abstract This thesis explores how interactions and feedbacks between environmental and socio-historical factors influenced fire management dynamics in north-east Namibia. Fires are mostly human ignited, but precipitation patterns influence when and where fires can occur, and there are feedbacks between fire, climate and vegetation cover. Yet, knowledge of historical and contemporary use of fire by societies is fragmented in southern Africa, and is therefore disputed. As a result, the complex interaction between climate, vegetation and human factors that influence fire dynamics remains poorly understood. This thesis explores how the political history, livelihoods, land-use practices, policy changes, vegetation and climatic variation are relevant to present-day fire regimes and management. The study is located in Bwabwata National Park (BNP), north-eastern Namibia, which is managed for both conservation objectives and people’s livelihoods. The park is inhabited by the Khwe (San), former hunter-gatherers, who have been using fire for millennia, and the Bantu-speaking Mbukushu people, who are agriculturalists and pastoralists. The area has been subject to colonial regimes, war, inter-ethnic conflict, social-political resettlement, conservation and associated changing fire management approaches since the 19th century. The vegetation includes omiramba grasslands, savanna-woodlands, Burkea shrublands and riparian types. For this study, qualitative semi-structured interviews with Namibian stakeholders, in combination with multi-year (2000 – 2015) remote sensing products, were used to understand the past and present fire regime characteristics. Interviews with community stakeholders revealed that the Khwe and Mbukushu communities use fire for a diverse range of livelihood activities. Specifically, early season burning is used to assist in hunting, tracking and gathering of veld foods, and for improving forage for livestock. The traditional practice of early season burning is not only culturally and ecologically significant, but has positive consequences for Bwabwata National Park’s conservation objectives, and fire policies, in terms of suppressing late season fires. However, explicit marginalisation of the Khwe since the C19th due to colonial regimes and cross-border wars has disrupted traditional fire management. Interviews with government and conservation stakeholders revealed recognition of the benefits of early season burning for biodiversity. Furthermore, despite the complex social-ecological history of the area, recent policy changes reveal an emerging willingness to incorporate traditional fire management into fire management policy. Moderate Resolution Imaging Spectrometer (MODIS) data was used to analyse the fire regime (burned area, fire frequency, fire number and size, intensity, and seasonality), together with climate (El Niño Southern-Oscillation [ENSO] events; local rainfall patterns) and vegetation data in multiple use (inhabited) and core conservation areas, over a time period that covered a shift in policy from fire 3 suppression (2000-2005) to early season burning (2006-2015). Results from the analysis of the MODIS data revealed that a high frequency of early season burning in the inhabited areas of the park reduced the late season fires and dampened the local rainfall and burned area relationship. Nonetheless, grass growth (i.e. available biomass) during ENSO wet season events (La Niña) resulted in greater area burned and fire sizes in above average rainfall years in the early dry season in the community inhabited areas. In contrast, higher fire intensity and larger fire sizes were evident in the conservation core areas where people were not actively burning. Fire frequencies and burned areas were highest in the omiramba grasslands and savanna-woodlands, in the early dry season under the early burning policy in the east of the park, which reduced fire intensities in these vegetation types. In contrast, burning in the Burkea shrublands was frequent in the late dry season, at higher intensities in the Western conservation area under both policy phases. This study indicates that burned area depends on rainfall, ignitions and fire sizes in inhabited landscapes, where people practice early burning, which has consequences for decreasing the intensity and therefore spread and impact of fires on vegetation. This study highlights the complex interactions between people, rainfall seasonality and fuel availability, as well as the need to incorporate historical factors. The study uses a pyrogeographic framework to integrate the social-cultural, climatic-biological, and topographic-environmental factors with fire. The synthesis reveals that the park communities are currently socially and ecologically vulnerable to global environmental change, given their dependence on fire for ecosystem services. However, the study also highlights how traditional fire management, and specifically early season burning, improves food security and contributes to livelihood subsistence and biodiversity conservation in the park. BNP is characterised by complex historical and present-day social-ecological fire dynamics. The study highlights the importance of understanding the historical and political context of fire for determining and managing current spatial-temporal fire patterns. Respect for diverse fire knowledge and culture, communication and shared governance are central to improving community livelihoods and fire management strategies in BNP. Specifically, the shared interest in early season burning provides a point of confluence between diverse stakeholders in BNP and a basis for fire management policies that benefit biodiversity as well as livelihoods. 4 Acknowledgements I am extremely appreciative of the people in Namibia that willingly opened their doors for this research to become a reality. One very rewarding aspect of participating in research is that one is introduced to many interesting people, stimulating conversations, and experiences that stay with one for life, that are untold. Namibia, and its people are remarkable in this regard. To Sophie and Alan Simmonds for their vast support, and for making this research possible right from the start – a heartfelt, thank you. Great appreciation is extended to all the Khwe and Mbukushu people who willingly shared of their fire knowledge. Thanks to Thadeus Chedau, David Singonhi, Soner Geira, Sandra, Peter Msiliso and Sebastian Kamwanga, the translators with whom I worked, who without this work would not have been possible; also to Alfred Berry and Pheedan Mpangu for protection whilst out in the beautiful wilds of Bwabwata. I’m extremely grateful to Margie Jacobsohn, Karine Nuulimba and Frederick Alpers of the IRDNC for providing the opportunity to engage in work in Bwabwata alongside the community, and for making this project possible from the start. I would like express gratitude to Lise Haansen, Carol Murphy, Simon Mayes and Johan le Roux for their assistance and insight. I owe thanks to the Ministry of Environment and Tourism, and Kenneth !Uiseb for the granting of the research permits for this work. Further, appreciation is extended to Volker Schiller and Helen Priest for willingly providing endless contacts of knowledgeable people in the area, and for housing support in the town of Katima Mulilo. To Harvey Park for providing a land cruiser for use whilst setting course in deeper Kalahari sands. I am immensely grateful to my supervisor, Lindsey Gillson, for her unstinting support, advice, encouragement and willingness to explore during this research project. Working with you has been a highlight, and immensely satisfying, thank you. Further, great appreciation is extended to Sophie Simmonds, Sally Archibald, Gina Ziervogel, Jacqui Sommerville, Andy Moore, Timm Hoffmann, William Bond, Cherie Forbes, Louis Liebenberg and the late Fred Kruger for advice and input during this project. I am grateful to all the fellow students at the Plant Conservation Unit (PCU) discussion group for constructive research input, as well as to the GreenMatter Fellows. Appreciation is extended to the Environmental Information Systems (EIS) team (John Mendelsohn & Alice Jarvis), NASA MODIS, and the National Botanical Research Institute (NBRI) for providing accessible and useable data; it’s a wealth of resources that would not be available otherwise. The Round River Conservation Studies, Diganta
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