Wildflowers: dalla conservazione della biodiversità alla progettazione del paesaggio

Natural and semi-natural grasslands throughout the world have high biodiversity values. Most grasslands have been controlled by grazers or by human management, especially mowing. The increasing diffusion of confined livestock farming and pasture abandonment have reduced the extent of these grasslands. In recent years, the threat of the disappearance of such diversity including the above and belowground organisms, has aroused growing interest in these complex ecosystems. The strategies for the conservation and restoration of semi-natural grassland and how they could be reintroduced into natural and disturbed environments have been studied. Research has focused on the dynamics of these plant communities and on understanding how to preserve and to improve the biodiversity, through the study of soil fertility, especially nitrogen content, which affects directly the productivity in terms of biomass and, indirectly, the biodiversity. Also the ecological strategies of the herbaceous species growing in these phytocenoses, i.e. how stress and disturb affect the presence and the absence of the species, have been matter of studies. The factors that affect the biodiversity of herbaceous systems have also been investigated, such as soil fertilization, grazing, and mowing. Studies on the re-introduction of native herbaceous species into disturbed environments (e.g., intensive agriculture, post-industrial and urban landscapes) have increased in recent years. In the urban landscape, cultural and ornamental aspects tend to prevail over conservation, and seed mixtures containing a high percentage of flowering plants, native and exotic, are commonly used. This review reports on the state of the art of the research on wildflowers communities, and shows some developments of the commercial seed production of the species used in these communities.