|Abstract||Abstract: One of the major obstacles to achieving important political goals for conservation of biodiversity is the lack of adequate standards and indicators to measure success or failure of conservation efforts. This shortcoming is partly due to the lack of a concept, methodology, and tested implementation for a widely acceptable standardized design for measurement of change of biodiversity within ecosystems and real landscapes. Any such design needs to (i) enable long-term monitoring of biodiversity, potential driving factors, and relevant indicators with adequate spatial and temporal resolution, (ii) facilitate comparability of data generated within different ecosystems, (iii) allow integration of many disciplines, (iv) allow spatial up-scaling, and (v) be applicable within a network approach. In 2000, the international, interdisciplinary biodiversity research project BIOTA AFRICA initiated a standardized biodiversity monitoring network along climatic gradients across the African continent. Due to the lack of an adequate monitoring design, BIOTA AFRICA developed and implemented a standardized design meeting the above criteria, the BIOTA Biodiversity Observatories. These are spatially explicit, interdisciplinary, long-term observation sites designed for monitoring the dynamics of ecosystems in general and of biodiversity in particular. A BIOTA Observatory encompasses an area of 1 km² and is subdivided into 100 1-hectare plots. For meeting the needs of sampling of different organism groups, the hectare plot is again subdivided into standardized subplots, whose sizes follow a geometric series. To allow for different sampling intensities but at the same time to characterize the whole square kilometer, the number of hectare plots to be sampled depends on the requirements of the respective discipline and on habitat patterns. A hierarchical ranking of the hectare plots ensures that all disciplines monitor as many hectare plots jointly as possible. The BIOTA Observatory design assures repeated, multidisciplinary standardized inventories of biodiversity and its driving factors, including options for spatial up- and downscaling and different sampling intensities. BIOTA Observatories have been installed along climatic and landscape gradients in Morocco, West Africa, and southern Africa. In regions with varying land use, several BIOTA Observatories are situated close to each other to analyze management effects. BIOTA Observatories have been monitored over nine years by African and German researchers, representing various disciplines (i.e. botany, lichenology, zoology, microbiology, soil science, climatology, and socio-economics). BIOTA Observatories contribute to the long-term biodiversity monitoring obligation of the host countries as required of countries that signed the Convention on Biological Diversity (CBD) and provide infrastructure and baseline data for ecological research.