Biological diversity and ecological functions have been observed and maintained on green roofs worldwide. Prairies, meadows, grasslands, wetlands, talus slopes, barrens, and successional plant communities are a few examples of habitat types that have been synthesized on green roofs. Nutrient cycling, plant dynamics, insect communities, evapotranspiration, and stormwater retention are some of the ecological functions studied from these communities. A group of twelve green roofs were selected as case studies to reiterate and highlight the key concepts covered in the previous chapters. This chapter provides examples of how green roofs have been designed and maintained as living, dynamic ecosystems.