Norwegian University of Life Sciences Faculty of Environmental Science and Technology Department of Ecology and Natural Resource Management Master Thesis 2014 60 credits Effects of anthropogenic disturbances on ground beetle (Coleoptera, Carabidae) communities in Afromontane forests: a comparison between habitats with different levels of disturbance in Amani Nature Reserve, Tanzania. Lore Geeraert Photo taken by author (September 2013) ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS First and foremost, I would like to thank my supervisor, Fred Midtgaard (professor at the Norwegian University of Life Sciences), for all his help and advice prior to and during my fieldwork, as well as during my writing process. He always provided me positive support, and generous amounts of time. A special thanks also goes to my co-supervisor, Seif Madoffe (professor at the Sokoine University of Agriculture in Morogoro, Tanzania), for his time and help during my fieldwork. His warm African personality was both very helpful and enriching. I would like to thank Thrond Oddvar Haugen, for spending a lot of time helping me out with my statistical analyses, even though his schedule was already fully booked. Also Rafael Leandro de Assis, Markus Sydenham, and Sam Steyaert provided me help with, and new knowledge about, statistically analysing my data. I am also thankful to Endre Hofstad Hansen for providing help during the preparations of my fieldwork. I am grateful to the Department of Ecology and Natural Resource Management (INA) of the Norwegian University of Life Sciences and to the CCIAM-program for financially supporting my fieldwork. I would like to thank Kijazi Mwanaidi, the conservator of the Amani Nature Reserve, and the complete Amani Nature Reserve crew for their incredibly warm friendship and support during my fieldwork. Robert, Rose, Violet, and Rose deserve an additional thank you for their fantastic cooking skills. Aloyce and Salim deserve an additional thank you for their excellent guiding skills and field assistance. Cecilie Notø also deserves a special acknowledgement. She kept me company during my entire fieldwork, while conducting her own fieldwork in the same nature reserve. Her friendship and support during the fieldwork and writing process has been of indescribable value to me. Last but not least, I want to thank my parents with all my heart for their full emotional and financial support during my studies. Also, without the support of my beloved sister (Hanne Geeraert), and other good friends (not only with the Belgian nationality, but with nationalities from all over the world) I would not have been able to enjoy my studies at the NMBU as much as I did. I thank them all from the bottom of my heart. Ås, May 2014 Lore Geeraert I II ABSTRACT ABSTRACT The family of ground beetles (Coleoptera, Carabidae) is one of the most species-rich coleopteran families. Ground beetles are good indicators of habitat disturbances, and could provide valuable information for sustainable management planning. Most studies are, however, restricted to temperate regions, even though tropical forests have the highest potential biodiversity loss. This study aimed to investigate effects of land-use change on the ground beetle communities in northeastern Tanzania. The study area was located in Amani Nature Reserve, a reserve that is situated in a biodiversity hotspot. The original tropical montane forest habitat in this reserve has been reduced due to historical logging activities. Currently, a few primary forest habitats coexist with several secondary forest habitats, plantation forests, and agroforestry land. Six sites, located in habitats with different disturbance degrees, were chosen: undisturbed forest, secondary forest that was moderately logged in the past, secondary forest that was heavily logged in the past, riverine secondary forest that was moderately logged in the past, an agroforestry habitat, and a recently logged part of the secondary forest that was heavily logged in the past. In total, 157 ground beetles, representing sixteen morphospecies, were collected during eight sampling weeks, using pitfall traps. The results of this study showed that all sampled sites had a significantly different ground beetle composition. An increasing ground beetle abundance was found with an increasing disturbance degree, while the species richness, species evenness, and the diversity decreased. The agroforestry site had a significant higher abundance compared to the undisturbed forest site, the moderately disturbed forest site, and the riverine forest site. The logging site had a significant higher abundance compared to the moderately disturbed, and the riverine forest site. No significant differences in observed species richness were found across the sampled sites. III IV TABLE OF CONTENTS TABLE OF CONTENTS ACKNOWLEDGEMENTS ................................................................................................................. I ABSTRACT ................................................................................................................................. III 1. INTRODUCTION ........................................................................................................................ 1 2. MATERIALS AND METHODS ..................................................................................................... 5 2.1. Study area ........................................................................................................................ 5 2.2. Study species ................................................................................................................... 7 2.3. Carabidae identification ................................................................................................... 8 2.4. Study design .................................................................................................................... 8 2.5. Covariates ...................................................................................................................... 14 2.6. Statistical analyses ......................................................................................................... 15 3. RESULTS ................................................................................................................................ 18 3.1. Adjustments ................................................................................................................... 19 3.2. Morphospecies analysis ................................................................................................. 19 3.3. Habitat analysis .............................................................................................................. 21 3.4. Site-specific covariates .................................................................................................. 24 3.5. Morphospecies-specific covariates ................................................................................ 28 3.6. Sample round-specific covariate ................................................................................... 30 3.7. Zero-inflated poisson regression ................................................................................... 30 4. DISCUSSION ........................................................................................................................... 32 4.1. Sampling method ........................................................................................................... 39 REFERENCES ............................................................................................................................. 42 APPENDIX 1 .................................................................................................................................. i APPENDIX 2 ................................................................................................................................. ii APPENDIX 3 ................................................................................................................................ iii APPENDIX 4 ................................................................................................................................ iv APPENDIX 5 ................................................................................................................................. v APPENDIX 6 ................................................................................................................................ vi APPENDIX 7 ............................................................................................................................... vii APPENDIX 8 .............................................................................................................................. viii APPENDIX 9 ................................................................................................................................ ix V 1. INTRODUCTION 1. INTRODUCTION Tropical forests contain world’s highest biodiversity (Lewis 2009). These forests are situated in areas that also have the highest anthropogenic pressures on the local biodiversity, because human populations are growing and developing most rapidly in the tropical regions (Lewis 2009). This combination of high anthropogenic pressures and biodiversity levels indicates that tropical forests have the highest potential biodiversity loss, which will result in changes in ecosystem structures and functions (Lewis 2009). Approximately half the world’s closed-canopy tropical forest areas are converted already