The Ezemvelo Thesis
Total Page:16
File Type:pdf, Size:1020Kb
THE DIVERSITY AND ECOLOGICAL IMPACTS OF BUPRESTID AND CERAMBYCID BEETLES ON EZEMVELO NATURE RESERVE, GAUTENG PROVINCE by DUNCAN NEIL MACFADYEN Submitted in partial fulfilment of the requirements for the degree MAGISTER TECHNOLOGIAE: NATURE CONSERVATION Department of Nature Conservation TSHWANE UNIVERSITY OF TECHNOLOGY Supervisor: Prof. B.K. Reilly Co Supervisor: Dr C.L. Bellamy February 2005 DECLARATION The compilation of this thesis and the work reported on is the result of the author’s original work, unless specifically acknowledged, or stated to the contrary, in the text. _________________________ 2 D.N. MacFadyen September 2004 ABSTRACT Understanding the extent and cause of insect diversity on a nature reserve is often seen as a challenge to reserve management. Recent calculations that there may be more than 20 million species of insects on earth have focused attention on their magnitude and stimulated several new lines of research (although the true figure is now widely thought to be between five and ten million species). This study discusses work based on light trapping, beating and sweeping surveys, plant association, seasonal change and community dynamics of Cerambycidae and Buprestidae, families of the Order Coleoptera. It is argued that progress in estimating insect diversity in understanding insect community dynamics will be enhanced by building local inventories of species diversity, and in descriptive and experimental studies of the structure of communities. As can be seen from their diaries and notebooks, contemplation of how such wonderful abundance and variety might arise was instrumental in pointing Darwin and especially Wallace to the theory of natural selection (Godfray et al. 1999). This study was undertaken to investigate the community structure of two families of wood-boring beetles, providing a more systematic and quantitative approach to cataloguing insect diversity in a protected area context. 3 ACKNOWLEDGEMENTS I would like to thank the following persons and organisations for their input to this study: The Tshwane University of Technology and E Oppenheimer & Son for financial assistance. Morgan Hauptfleish (reserve manager) for providing background information regarding the management practices of Ezemvelo Nature Reserve. He is also thanked for logistical support. Dr C.L. Bellamy and Ruth Müller for taking the time and effort to aid in identification of the numerous beetle specimens. Prof. George Bredenkamp is also thanked for assistance with categorizing the plant features. The following people assisted me in various capacities: Marion Burger, Tersia Perregil, Patrick Wood, Stuart Smith, Nelius Uys, Willem van der Merwe and Tracey MacFadyen. My parents, especially my father, Neil MacFadyen, for his support, motivation and faith in me during the course of this study. Prof. B.K. Reilly for his valued guidance, support and encouragement throughout the course of this study. His tolerance, assistance and patience during the compilation of this thesis was also sincerely appreciated. Finally, I would like to thank Strilli Oppenheimer, whose great love for insects led to this project being conceived. 4 INDEX 5 PAGE Declaration ...…………………………………………………………………………… 1 Abstract ….………………………….………………………………………………….. 2 Acknowledgements ...………………………………………………………………....... 3 Index ……………………………………………………………………………………. 4 Chapter One 1. INTRODUCTION……………………………………………………………… 32 1.1 Views of the insect community …………………………………….................... 35 1.2 Rationale for this study ………………………………………………………… 36 1.3 Objectives ………………………………………………………………………. 37 1.4 Hypotheses …………………………………………………..…………………. 37 Chapter Two 2. MATERIALS AND METHODS……………………………………………… 38 2.1 STUDY AREA………………………………………………………………….. 38 2.1.1 Phytosociology………………………………………………………………....... 39 2.1.2 Geology………………………………………………………………………….. 40 2.1.3 Soil………………………………………………………………………………. 40 2.1.4 Climate………………………………………………………………………....... 40 2.1.5 Hydrology……………………………………………………………………….. 40 PAGE 6 2.1.6 Vegetation………………………………………………………………………..6 2.2 METHODS…………………………………………………………………….. 2.2.1 Preparatory Work………………………………………………………………... 2.2.2 Reconnaissance………………………………………………………………….. 2.2.3 Stand and quadrant dimensions………………………………………………….. 2.2.4 Positioning of quadrats………………………………………………………....... 2.2.5 Field location of quadrats………………………………………………………... 2.2.6 Layout and orientation of quadrats………..…………………………………….. 2.3 Field data collection…………………………………………………………….. 2.3.1 Abiotic factors………………………………………………………………....... 2.3.2 Biotic factors……………………………………………………………………. 2.3.2.1 Plants……………………………………………………………………………. 2.3.2.2 Beetle families………………………………………………………………….. 2.3.3 Collection methods……………………………………………………………… 2.3.3.1 Beating method…………………………………………………………………. 2.3.3.2 Sweeping method……………………………………………………………….. 2.3.3.3 Sheet trap method……………………………………………………………….. 2.3.4 Identification of beetles………………………………………………………….. 2.3.5 Data preparation…………………………………………………………………. 2.3.6 Statistical analysis……………………………………………………………….. 2.3.6.1 Chi Square analysis………..…………………………………………………….. 2.3.6.2 Cramér’s V analysis…………………………………………………………....... 2.3.6.2 Cramér’s V analysis…………………………………………………………....... Chapter Three 3. RESULTS……………………………………………………………………… 3.1 Cerambycidae data…..………………………………..…………………………. 3.1.1 Total Cerambycidae data……………….……………………………….............. 3.1.2 Quadrat A……………………………………………………..…………….......7 3.1.3 Quadrat B…………………………………………………………………......... 3.1.4 Quadrat C………………………………………………………………………. 3.2 Buprestidae data……………………...…………………………………………. 3.2.1 Total Buprestidae data………………………………………………………..... 3.2.2 Quadrat A……..……………………………………………………………..... 3.2.3 Quadrat B……………………………………………………………………..... 3.2.4 Quadrat C……………………………………………………………………..... 3.3 Ecological processes affecting Cerambycidae and Bupresridae on ENR……….. 3.4 Cerambycidae/Plant correlation………..………………………………………. 3.4.1 Plant order correlation…………………………………………………………. 3.4.2 Plant family correlation…...………………………………………………....... 3.4.3 Plant species correlation…………………...…………………………………... 3.4.4 Plant flower size correlation…………………………………………………… 3.4.5 Plant phenology correlation…………………………………………………... 3.4.6 Plant pollination………………………………………………………………... 3.4.7 Plant climate…………………………………………………………………..... 3.5 Buprestidae/Plant correlation……………………………………………………. 3.5.1 Plant order correlation………………………………………………………....... 3.5.2 Plant family correlation…………………………………………………………. 3.5.3 Plant species correlation…………...……………………………………………. 3.5.4 Plant flower size correlation…….………………………..…………………....... 3.5.5 Plant phenology correlation……….………………..…………………………… 3.5.6 Plant pollination…………………………………………………………………. 8 3.5.7 Plant climate…………………………………………………………………....... 3.6 Discussion……………………………………………………………………….. Chapter Four 4. DISCUSSION…………………………………………………………………… 4.1 Classification of Buprestoidea…………………………………………………... 4.2 Classification of Cerambycidae…………………………………………………. 4.3 Factors influencing the abundance and diversity on ENR………………...…….. 4.3.1 Cerambycidae abundance and diversity on ENR……………………………....... 4.3.2 Buprestidae abundance and diversity of ENR………...………………………… 4.4 Overview………………………………………………………………………… Chapter Five 4 ECOLOGICAL IMPORTANCE AND FUTURE MANAGEMENT OF CERAMBYCIDAE AND BUPRESTIDAE ON EZEMVELO NATURE RESERVE………………………………………………………………………….. Chapter Six 5 CONCLUSION…………………………………………………………………….. Chapter Seven 6 REFERENCES……………………………………………………………………… LIST OF FIGURES Figure 1: Map of South Africa showing Ezemvelo Nature Reserves positioning on the border of Gauteng and Mpumalanga provinces………………………………. 9 Figure 2: The greater Telperion Nature Reserve with Ezemvelo Nature Reserve on the western boundary divided by the Wilge River………………………………... Figure 3: The Wilge river on Ezemvelo Nature Reserve is dominated by rocky outcrops and woody vegetation……………………………………………… Figure 4.1: Ezemvelo Nature Reserve and quadrats (A, B & C) with overlaying slope classes……………………………………………………. Figure 4.2: Ezemvelo Nature Reserve and quadrats (A, B & C) with overlaying altitude categories……………………………………….... Figure 4.3: Ezemvelo Nature Reserve and quadrats (A, B & C) with overlaying aspect classes…………………………………………………... Figure 4.4: Broad vegetation zones of Ezemvelo Nature Reserve showing placement of quadrats A,B & C………………………………….. Figure 5.1.1: Transect line A1 within quadrat A in September 2001 on Ezemvelo Nature Reserve……………………………………………… Figure 5.1.2: Transect line A2 within quadrat A in September 2001 on Ezemvelo Nature Reserve……………………………………………… Figure 5.1.3: Transect line A3 within quadrat A in September 2001 on Ezemvelo Nature Reserve……………………………………………… 10 Figure 5.2.1: Transect line B1 within quadrat B in September 2001 Figure 5.2.1: Transect line B1 within quadrat B in September 2001 on Ezemvelo Nature Reserve………………................................................. Figure 5.2.2: Transect line B2 within quadrat B in September 2001 on Ezemvelo Nature Reserve…………………………………………….. Figure 5.2.3: Transect line B3 within quadrat B in September 2001 on Ezemvelo Nature Reserve…………………………………………….. Figure 5.3.1: Transect line C1 within quadrat C in September 2001 on Ezemvelo Nature Reserve…………………………………………….. Figure 5.3.2: Transect line C2 within quadrat C in September 2001 on Ezemvelo Nature Reserve…………………………………………….. Figure 5.3.3: Transect line C3 within quadrat C in September 2001 on Ezemvelo Nature Reserve……………………………………………... Figure 6.1.1: The beating method being used on Protea caffra in quadrat C on Ezemvelo Nature Reserve………………………………….. Figure 6.1.2: The beating method being used on Acacia caffra