The Okavango Basin is situated in south central Africa and shared among the three countries of Angola, Namibia and Botswana. The Okavango River has its source on the sub-humid Angolan Central Plateau where 95% of the runoff is generated. The river terminates in the endorheic Okavango Delta in the Kalahari Desert, forming a world renowned wetland ecosystem highly dependent on the annual inflow of water of the Okavango River. However, the upper reaches of the river in the Angolan Miombo belt are highly understudied; ecological data and understanding of ecosystem functioning are lacking. At the same time, the socio-ecological systems of the upper Basin are subject to rapid transformations and are regarded as a hot spot of accelerating land use change. However, the largely subsistence based economy of the rural communities is highly dependent on the continued delivery of a wide range of ecosystem services. Thus, the presented thesis aims to provide scientific data to contribute to a sustainable development and to safeguard plant diversity in the Okavango Basin. The thesis focuses on three general aspects: a) the analysis of plant species composition and diversity and their underlying environmental drivers, b) the development of methodological tools to combine field data and remote sensing information to provide spatially explicit data, c) the investigation of the impact of land use on vegetation and plant diversity. The thesis hence combines methods of traditional vegetation ecology with the application of remote sensing information and the development of innovative ecological modelling approaches to upscale the knowledge gained in field studies at the local scale to the scale of the Okavango Basin.