Urban ecosystems are complex systems that involve interactions between humans, the built environment, and the natural world. They are characterized by a variety of physical, chemical, and biological components. Key challenges for urban ecosystems include maintaining a balance between human and natural needs while relying on substantial imported resources. Some ways to manage and sustain urban ecosystems include using green infrastructure like parks and urban forests, promoting biodiversity, encouraging sustainable transportation, conserving water and reducing waste. Additional factors for sustainable urban development are economic, social, and environmental sustainability as well as citizen engagement and integrating the three pillars of sustainability in areas like planning, transportation, and social equity.