For several years, urban nature has become a major theme in academic litterature, especialy urban vegetation. Some authors are particularly interested in the vegetation located in industrial abandoned sites, vacant lots or train right-of-way. They have oriented their work towards the dispersal patterns of weeds, including their origin and the spatial distribution of species in the urban area. Several authors compare the green open spaces to urban islands, inspired by the island biogeographical theory. These isolated green open spaces constitute, as it were, insular spaces dispersed in the agglomeration and it is suggested that models of dispersion and biological exchanges are similar to the dispersion of vegetation on ocean islands, for example. In the perspective of conservation and restoration of open green spaces, the concept of green corridors or green links has emerged as an interesting alternative, not only to produce new urban green spaces but also to create a green urban network. This paper examines the biogeographical approches as regards to the planning of parks and green spaces in urban habitats.