Climatic gradients and patchy soil factors are influencing the vegetation patterns and dynamics in drylands. These fragile ecosystems, often at the fringe of deserts, are endangered by climate change and desertification. Understanding the ecological processes in time and space is important for sustainable land-use and the protection of biodiversity. Climatic gradients are often used as model systems to analyse the consequences of global change on vegetation and ecosystems. However, the knowledge of interactions of these processes on different scales is limited. Several case studies from South and Central America, Southern Africa and the Middle East showed the complex interactions along gradients in drylands. Linking processes from regional and local scales are still a challenge in ecology. Models will help for the development of sustainable land-use and natural resources use strategies and for the conservation of biodiversity.