The SASSCAL region is home to a very rich biodiversity, which provides significant economic and intrinsic value to human society. Th is biodiversity, however, is subject to multiple stresses emerging from human land use and climate change, which leads to biodiversity loss at substantial scale. To assess the current state and changes in biodiversity in the SASSCAL region, a standardised biodiversity observation network has been established. Th e network comprises 47 biodiversity observatories and 10 auxiliary observatories, where biodiversity change is monitored according to a standardised approach. Th e network currently covers the countries of Angola, Namibia, Zambia, and South Africa. The newly established observatories in Angola and Zambia provided urgently needed baseline inventory data on flora and faunal species for the study areas. The observatories in Namibia and South Africa already extend up to 17 or even 30 years and provide important insights into the complexity of the biodiverse systems and their drivers. We provide an overview of the outcomes of the biodiversity assessment and monitoring work at the observatories. We discuss the contribution of these findings for the understanding of the systems and their changes over time. We also outline new approaches (e.g. experiments, monitoring of key ecological processes like the water pathways in the vegetation, as well as automatised monitoring) to be applied in the ongoing monitoring activities.