The role of disturbances in mangrove wood
formation and forest structure
Effect of large sedimentation events
Thesis submitted in fulfillment of requirements for the degree of Doctor of philosophy in Bioengineering Science
of the Vrije Universiteit Brussel and Université Libre de Bruxelles
By
Judith Auma OKELLO
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Table of contents
Contents
Summary ... Error! Bookmark not defined. Samenvatting... Error! Bookmark not defined. Résumé ... Error! Bookmark not defined. Glossary ... Error! Bookmark not defined. List of acronyms and magnitudes ... Error! Bookmark not defined. PART I: Introduction and rationale ... Error! Bookmark not defined. CHAPTER 1: Introduction ... Error! Bookmark not defined. 1.1 Mangrove ecology and distribution ... Error! Bookmark not defined. 1.2 Mangrove biogeography ... Error! Bookmark not defined. 1.3 Mangrove values... Error! Bookmark not defined. 1.4 Threats to mangrove ecosystems ... Error! Bookmark not defined. 1.5 The concept of disturbance and alternative stable states ... Error! Bookmark not
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1.6 Sediment dynamics and sedimentation in the mangrove environment ...Error!
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1.7 Xylem structure and hydraulic conductance with respect to stress/ disturbance Error!
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1.8 Mangroves of Kenya ... Error! Bookmark not defined. CHAPTER 2: The study ... Error! Bookmark not defined.
2.1 The species studied: Avicennia marina, Ceriops tagal and Rhizophora mucronata. ... Error! Bookmark not defined. 2.2 The study sites ... Error! Bookmark not defined. 2.3 Study rationale ... Error! Bookmark not defined. PART II: The mangroves of Mtwapa Creek ... Error! Bookmark not defined. CHAPTER 3: Self-sustenance potential of peri-urban mangroves: a case of Mtwapa Creek Kenya ... Error! Bookmark not defined.
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CHAPTER 4: State and future of mangroves of Mtwapa Creek - Kenya as perceived by the local communities ... Error! Bookmark not defined. Abstract ... Error! Bookmark not defined. 4.1 Introduction ... Error! Bookmark not defined. 4.2 Materials and Methods ... Error! Bookmark not defined. 4.3 Results ... Error! Bookmark not defined. 4.4 Discussion ... Error! Bookmark not defined. 4.5 Conclusion ... Error! Bookmark not defined. PART III: Experimental sedimentation in the mangroves of Gazi Bay, Kenya ...Error!
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CHAPTER 5: Effects of experimental sedimentation on the phenological dynamics and leaf traits of replanted mangroves at Gazi Bay, Kenya. ... Error! Bookmark not defined.
Abstract ... Error! Bookmark not defined. 5.1 Introduction ... Error! Bookmark not defined. 5.2 Materials and methods ... Error! Bookmark not defined. 5.3 Results ... Error! Bookmark not defined. 5.4 Discussion ... Error! Bookmark not defined. 5.5 Conclusion ... Error! Bookmark not defined. CHAPTER 6: Partially buried mangrove trees ensure continued hydraulic conductivity through adjustment in xylem structure. ... Error! Bookmark not defined.
Abstract ... Error! Bookmark not defined. 6.1 Introduction ... Error! Bookmark not defined. 6.2 Materials and methods ... Error! Bookmark not defined. 6.3 Results ... Error! Bookmark not defined. 6.4 Discussion ... Error! Bookmark not defined. 6.5 Conclusions and perspectives ... Error! Bookmark not defined. CHAPTER 7: Mangrove trees survive partial sediment burial by developing new roots and adapting their root, branch and stem anatomy ... Error! Bookmark not defined.
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PART IV: Synthesis ... Error! Bookmark not defined. CHAPTER 8: General discussion - Conclusions and perspectives... Error! Bookmark not
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8.1 Summary of the findings ... Error! Bookmark not defined. 8.2 Disturbance influences forest structure ... Error! Bookmark not defined. 8.3 Resilience of mangroves under instantaneous large sedimentation Error! Bookmark
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8.4 Higher or maintained hydraulic conductivity in partially buried mangroves, is it a norm? ... Error! Bookmark not defined. 8.5 Role of nutrients and crab burrowing in partially buried mangroves ...Error!
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