The heterogeneous structure of nature leads to a huge variety of different habitats for different species and thus, spatial structures are one of the major agents for biodiversity in natural systems. This is true over a wide range of spacial scales, starting from bacteria with a typical size of some 10-6 m to populations of elephants with a typical habitat of 105 m. The diversity of the related living space is a prerequisite for the coexistence of various species at a given location at the same time.