university of cape coast landscape influence on bee abundance and diversity in the forest ...

244 Pages·2016·2.29 MB·English

UNIVERSITY OF CAPE COAST

LANDSCAPE INFLUENCE ON BEE ABUNDANCE AND DIVERSITY IN
THE FOREST SAVANNAH TRANSITION ZONE OF GHANA AND
COMMUNITY KNOWLEDGE OF POLLINATORS AND POLLINATION

EDDIEBRIGHT JOSEPH BUADU

2016
UNIVERSITY OF CAPE COAST

LANDSCAPE INFLUENCE ON BEE ABUNDANCE AND DIVERSITY IN
THE FOREST SAVANNAH TRANSITION ZONE OF GHANA AND
COMMUNITY KNOWLEDGE OF POLLINATORS AND POLLINATION

BY
EDDIEBRIGHT JOSEPH BUADU

Thesis submitted to the Department of Entomology and Wildlife of the School
of Biological Sciences, University of Cape Coast in partial fulfilment of the
requirements for the award of Doctor of Philosophy degree in Entomology

JULY 2016
© Eddiebright Joseph Buadu
University of Cape Coast
DECLARATION
Candidate’s Declaration
I hereby declare that this thesis is the result of my own original work and that no
part of it has been presented for another degree in this university or elsewhere.

Candidate’s Signature:............................................................Date:......................
Name: Eddiebright Joseph Buadu

Supervisors’ Declaration
We hereby declare that the preparation and presentation of the thesis were
supervised in accordance with guidelines on supervision of thesis laid down by
the University of Cape Coast.

Principal Supervisor’s Signature:..............................................Date:........................
Name: Professor Peter Kofi Kwapong

Co-supervisor’s Signature:.......................................................Date:……………….
Name: Professor (Mrs) Mary Botchey
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ABSTRACT
Global declines in pollinator diversity and abundance have been recognized, raising
concerns about a pollination crisis of crops and wild plants. In many African
countries including Ghana however research and publications on the subject are
rare. To this end, a study was carried out from June 2013 to April 2014 to determine
the influence of landscape type on bee species abundance and diversity in the Forest
Savannah Transition Zone (FSTZ) of Ghana. The research also evaluated farmers’
knowledge and perceptions of the importance of pollinators and pollination. Two
sites each of the landscape types; Agricultural land, Natural vegetation and
Settlement fringes were sampled from three subzones selected on the basis of the
proportion of trees relative to grasses. Overall, 706 bees made up of 3 families, 18
genera and 34 species were collected and identified. Apidae was the most speciose
bee family and Megachilidae the least. Xylocopa, Amegilla and Lipotriches were the
most common genera whilst Chalicodoma, Thyreus, Celioxys and Lithurgus were
represented by single individuals. The results of bee species abundance and
diversity were mixed for the various comparisons. Overall, the study indicated that
bee species diversity is significantly influenced by landscape type and percentage
tree to grass proportions (P ≤ 0.05). No such variation was observed for bee
abundance probably due to the dominance of Apis mellifera Linnaeus. There were
significantly more bee species in agricultural land and natural vegetation than in
settlement fringes. Similarly, there were more bee species in the lower transition
zone (area with the highest percent tree cover) than in either the middle or upper
transition zone. Though most of the crop farmers interviewed had been farming for
more than 10 years, they knew very little about pollinators and pollination,
indicating the need to intensify education on the subject.
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ACKNOWLEDGMENTS
I am most grateful to God Almighty for granting me the grace to complete
this three year period of research.
I am highly indebted to Professor Peter Kofi Kwapong and Professor
(Mrs) Mary Botchey, my Principal and Co-Supervisor respectively. I sincerely
thank them for guiding me through this work.
Further, a special thank you is expressed to the College of Distance
Education (CoDE) Management, UCC for granting me a scholarship to undertake
this research work. I would like to acknowledge the tremendous help and good
will received from Mr. Albert Kobina Koomson, the former Director and
Professor G. K. T. Oduro, the current Provost.
I am also grateful to a number of individuals for the diverse roles they
played in ensuring the success of this work. Topmost on the list are Professor B.
A. Mensah, the Head of Entomology and Wildlife Department, Dr. Rofela
Combey, a bee taxonomist and a senior lecturer in the Department without whose
help the bees collected could not have been identified, Mrs. Janet Christabel
Arthur, a principal administrative assistant who worked on the graphs and
photographs in this thesis and Dr. Kwame Aidoo, a bee expert who provided
useful suggestions. Others are Frank Gyamfi, a former curator of the Entomology
museum, Mr. Edem Hope who helped with the statistical analysis as well as the
chiefs and assembly members of the study communities for permitting me to
conduct this study in their areas of jurisdiction.
I solemnly declare that I share the credit that goes with the production of
this work with my wife, Catherine and the children, Friedrich, Joana, Eugenia and
Prince for their prayers and moral support.
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DEDICATION
To my wife and children

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TABLE OF CONTENTS
Page
DECLARATION ii
ABSTRACT iii
ACKNOWLEDGEMENTS iv
DEDICATION v
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF ACRONYMS xv
CHAPTER ONE: INTRODUCTION 1
Background to the Study 1
Bees 4
Drivers of pollinator decline 6
Statement of the Problem 8
Purpose of the Study 14
Objectives of the Study 14
Hypotheses 14
Significance of the Study 15
Delimitation 16
Limitations 16
Definition of Terms 16
Organization of Study 17

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CHAPTER TWO: LITERATURE REVIEW 18
Forest Savannah Transition Zones 18
The Concept of Landscape 19
Importance of Pollinators 21
Ecosystems’ Dependence on Pollinators 25
Pollinators and Socio-economic Conditions in Ghana 26
Bee Pollinators 26
Social bees 27
Solitary bees 28
Bee Families 30
Factors Influencing Bee Abundance and Diversity 31
Floral resources 32
Nesting resources 33
Climatic factors 36
Natural and semi-natural habitats 40
Natural history traits 41
Land use factors 45
Pollinator Decline 50
Causes of Pollinator Decline 51
Bee Conservation Measures 55
Hedgerows 55
Field margins 55
Management of roadside habitats 56
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Management of fallows 56
Management of woodland and forest plantations 57
Management of natural forests 57
Management of grasslands and pasture lands 57
Managing floral resources within agricultural fields 58
Management to provide bee nesting sites within agricultural fields 60
Compensation to farmers 61
Information dissemination 62
Access to water 62
Minimizing direct exposure to risk 63
Knowledge of Pollinator Services 63
CHAPTER THREE: MATERIALS AND METHODS 68
Study Area 68
Sampling Sites and Field Work 69
Bee Sampling Methods 73
Laboratory Work 77
Survey of Crop Farmers in the Study Communities 78
Data Analyses 79
CHAPTER FOUR: RESULTS 82
The Bee Fauna of the FSTZ of Ghana 82
Bee Species Distribution in the FSTZ of Ghana 82
Total Numbers of Bees per Landscape Type and Subzone 85
Species Rarity Within the FSTZ of Ghana 88
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