This PhD study shows the effect of climate change on plant species diversity in Central Africa. Climate change is predicted to result in the loss of at least 10% of all investigated plant species and a maximum turnover in plant species composition of 75%. This study presents for the first time ever current and predicted future patterns of botanical diversity in Central Africa based on an assessment of more than 2000 plant species. To assess such patterns, species distribution models were generated for each individual species. Although such methods are widely used nowadays, no information was available on the minimum sample size required to generate accurate models. The methodological part of this thesis presents a new method to identify this required minimum sample size using simulated species. This method can be applied to species with different range sizes and for different study areas.