Chryseobacterium sp. ET-I9

........................................................................................................................................... 3 ACKNOWLEDGEMENTS ................................................................................................................... 4 CHAPTER 1 ........................................................................................................................................... 5 INTRODUCTION .................................................................................................................................. 5 CHAPTER 2 ........................................................................................................................................... 9 STUDY AREA ........................................................................................................................................ 9 SITE DESCRIPTIONS ............................................................................................................................ 11 CHAPTER 3 ......................................................................................................................................... 14 CAN THE TEMPORAL DISTRIBUTION OF RAIN EXPLAIN THE CO-EXISTENCE OF TREES AND GRASSES FOR TWO SITES IN THE KRUGER NATIONAL PARK? ................ 14 ABSTRACT .......................................................................................................................................... 14 INTRODUCTION ................................................................................................................................... 15 METHODS ........................................................................................................................................... 19 Rainfall records and statistical analysis ............................................................................... ........ i9 Levene's test of homogeneity of variance ......... ................................................. ., . ., ... ., ................. 19 RESULTS ............................................................................................................................................. 22 (i) is rainfall variability higher at Satara than Pretoriuskop? .................................................... 22 (ii) is there a relationship between the number of rain days and annual rainfall? ...................... 22 (iii) Does Pretoriuskop have a longer wet season compared to Salara ........................................ 24 (tv) is there a higher frequency of the right rainfall conditions for germination and survival occurring at Pretoriuskop compared to Salam? .......................................................................... 27 DiSCUSSION ........................................................................................................................................ 31 Predictions ......... ........................................................................................................................... 33 Conclusion ................................................ .................................................................................... 33 CHAPTER 4 ......................................................................................................................................... 36......................................................................................................................................... 14 INTRODUCTION ................................................................................................................................... 15 METHODS ........................................................................................................................................... 19 Rainfall records and statistical analysis ............................................................................... ........ i9 Levene's test of homogeneity of variance ......... ................................................. ., . ., ... ., ................. 19 RESULTS ............................................................................................................................................. 22 (i) is rainfall variability higher at Satara than Pretoriuskop? .................................................... 22 (ii) is there a relationship between the number of rain days and annual rainfall? ...................... 22 (iii) Does Pretoriuskop have a longer wet season compared to Salara ........................................ 24 (tv) is there a higher frequency of the right rainfall conditions for germination and survival occurring at Pretoriuskop compared to Salam? .......................................................................... 27 DiSCUSSION ........................................................................................................................................ 31 Predictions ......... ........................................................................................................................... 33 Conclusion ................................................ .................................................................................... 33 CHAPTER 4 ......................................................................................................................................... 36 THE INFLUENCE OF WET SEASON LENGTH ON DRY SEASON TREE SEEDLING SURVIV AL ........................................................................................................................................... 36 ABSTRACT .......................................................................................................................................... 36 INTRODUCTION ................................................................................................................................... 37 METHODS ........................................................................................................................................... 39 (i) Does the length of growth during the rainy season influence d,y season survival? ................ 39 (ii) When do tree species germinate? ............................................ ................................................ 44 (iii) What are the physiological adaptations to drought stress? ................................................... 45 Statistical Analysis ........................................................... , ... , ...................... , ................................. 45 (iv) Do savanna tree species create a seed bank .......................................................................... 46 RESULTS ............................................................................................................................................. 46 (i) Does the length of growth during the rainy season influence dry season survival? ................ 46 (ii) When do tree species germinate? .................................................................................. .......... 49 (iii) What are the physiological adaptations to drought stress? ................................................... 51 (iv) Do savanna tree species create a seed bank? ........................................................................ 56 DiSCUSSiON ........................................................................................................................................ 59 Predictions .............................................................. ...................................................................... 6/ Conc/usion .............................................................. ............................ , ......................................... 6/ CHAPTER 5 ......................................................................................................................................... 62 Un ive rsi ty of Ca pe To wn......................................................................................................................................... 36 INTRODUCTION ................................................................................................................................... 37 METHODS ........................................................................................................................................... 39 (i) Does the length of growth during the rainy season influence d,y season survival? ................ 39 (ii) When do tree species germinate? ............................................ ................................................ 44 (iii) What are the physiological adaptations to drought stress? ................................................... 45 Statistical Analysis ........................................................... , ... , ...................... , ................................. 45 (iv) Do savanna tree species create a seed bank .......................................................................... 46 RESULTS ............................................................................................................................................. 46 (i) Does the length of growth during the rainy season influence dry season survival? ................ 46 (ii) When do tree species germinate? .................................................................................. .......... 49 (iii) What are the physiological adaptations to drought stress? ................................................... 51 (iv) Do savanna tree species create a seed bank? ........................................................................ 56 DiSCUSSiON ........................................................................................................................................ 59 Predictions .............................................................. ...................................................................... 6/ Conc/usion ........................................