VTHE DISTRIBUTION, ABUNDANCE AND ECOLOGICAL IMPACTS OF INVASIVE PLANT SPECIES AT OL-DONYO SABUK NATIONAL PARK, KENYA BY JOSEPHAT K. WAMBUA UNIVERSITY OF NAIROBI, SCHOOL OF BIOLOGICAL SCIENCES. A THESIS SUBMITTED IN PARTIAL FULFILLMENT FOR THE DEGREE OF MASTER OF SCIENCE IN THE BIOLOGY OF CONSERVATION, UNIVERSITY OF NAIROBI. University of NAIROBI Library DECLARATION I JOSEPHAT K. WAMBUA do hereby declare that this is my original work and has not been submitted to any other University for examination. Declaration by supervisors. This thesis has been submitted for examination with our approval as University supervisors. 1) Dr. John Mworia. PhD. Signed ................................. Date... M i. d . M 1 ° 2) Dr. Nathan Gichuki. PhD. u Dedication. This work is dedicated to my children Lawrence Mwendwa and Lydia Kalondu the two of you have been my inspiration and driving force. Acknowledgement. This study was made possible through the help of various people. It is however not possible to mention each and everyone’s name here, but I sincerely appreciate and thank all of them. First, I would like to express my thanks to Dr. John Mworia and Dr. Nathan Gichuki my supervisors for their invaluable time that they spent in providing guidance during the study. Your availability and time allocation for this work was a pointer that you were dedicated to my academic endeavours. I would also thank Dr. Charles Musyoki of KWS for your moral support and encouragement to pursue the invasive species project. Your availability and guidance during the entire work is appreciated. Mr. Lekishon Kenana of KWS Biodiversity and research department, for your support during field work, The University of Nairobi School of biological sciences for giving me an opportunity to undertake my MSc. at the school. Kenya Wildlife Service for granting me study leave and financial support, Mr. Anthony Ndubi of Regional Centre for Mapping of Resources for Development (RCMRD) for your invaluable time and guidance in the analysis of digital imagery. The management and entire staff of Kenya wildlife Ol-donyo Sabuk National park for your support. Mr.Wilson Korir- Assistant Director Southern / conservation area for your invaluable support. Finally, my gratitude goes to my family, my wife Pauline and my children Lawrence Mwendwa and Lydia kalondu for having to endure my long time of moral absence. Your love and support has made me accomplish this work; I will always be indebted to you. IV List of acronyms. ASTER -Advanced space-borne thermal emission and reflection radiometer. NASA- National aeronautics and space administration. VNIR - Visible Near Infrared. SWIR -Short Wave Infrared. TIR - Thermal Infrared. IFOV - Instantaneous Field Of View PCA- Principal Component analysis. SVIs - Spectral vegetation indices. GPS - Global positioning system. ANOVA-Analysis of variance. EOS-Earth Observing System / \ V Table of contents. Page Declaration............................................................................................................ii Dedication............................................................................................................iii Acknowledgements............................................................................................. iv List of acronyms................................................................................................... v List of tables.........................................................................................................ix List of figures........................................................................................................ x List of appendices................................................................................................ xi Abstract.................... xii CHAPTER ONE..................................................................................................1 INTRODUCTION AND LITERATURE REVIEW............................................1 1.1 Introduction...................................................................................................1 1.2 Historical development.................................................................................2 1.3 Literature review........................................................................................... 3 1.3.1 Global invasive problem.........................................................................3 1.3.2 Use of remote sensing techniques in vegetation studies.........................7 1.3.3 Vegetation sampling techniques............................................................9 1.3.4 Birds and mammal sampling techniques.............................................. 9 1.3.5 Stratification of study area.......................................................*...........10 1.4 Study justification......................................................................................... 11 1.5 Problem statement........................................................................................ 12 1.6 Hypothesis.....................................................................................................14 1.7 Objectives......................................................................................................14 1.7.1 Main objectives...................................................................................... 14 1.7.2 Specific objectives................................................................................. 14 1.8 Research questions........................................................................................ 14 CHAPTER TWO.............................................................................................15 STUDY AREA, MATERIALS ANDMETHODS......................... 15 2.1 Study area.......................................................................................... 15 2.1.1 Physical location..................................................................................... 15 2.1.2 Climate.....................................................................................................17 2.1.3Tophography and drainage...................................................................... 17 2.1.4 Soils.........................................................................................................17 2.1.5 Plant communities................................................................................. 18 2.1.6 Wildlife communities............................................................................ 18 2.1.7 Social economic activities...................................................................... 19 2.2 Materials and methods.................................................................................. 19 2.2.1 Remote sensed data analysis...................................................................19 2.2.2 Analysis of satellite images....................................................................20 Acquisition of satellite images and pre-processing...............................20 2.2.3 Geometric correction..............................................................................21 2.2.4 Image enhancement................................................................................21 Principal component analysis............. f ................ *..................22 Spectral vegetation Indices................ \ ...................y ..'................... 22 2.2.5 Image Classification..’................................ 22 vi Accuracy assessment.......................................................................... 24 2.2.6 Determination of sample sizes........................................................... 25 2.2.7Determination of sampling grids and placement of transects.............. 26 2.2.8 Invasive plant species and distribution in the park.............................. 28 2.2.9 Assessment of invasive species impact on biodiversity...................... 28 2.3.1 Determination of birds and mammal species associated with Invasive plants.......................................................................................29 2.3.2 Factors related to the distribution of invasive species...........................30 2.3.3 Invasive plant species found on the immediate surroundings of the park..........................................................................................................30 2.4 Data analysis.............................................................. *.............................30 2.4.1 Remote sensed data................................................................................30 2.4.2 Vegetation sampling data.......................................................................31 2.4.3 Birds sampling data................................................................................32 2.4.4 Mammal sampling data...........................................................................32 2.4.5 Tests of association..............................!.................................................32 CHAPTER T H R E E ........................................................................................34 RESULTS.......................................................................................................... 34 3.1 Land cover stratification using remote sensed image................................34 3.1.1 Accuracy assessment results.................................................................. 38 3.2 Vegetation sampling data.............................................................................39 3.2.1Closed