The article "Engineering blue-green infrastructure for and with biodiversity in cities" by Kilian Perrelet, Marco Moretti, Andreas Dietzel, Florian Altermatt, and Lauren M. Cook advocates for integrating ecological and engineering objectives in the design of blue-green infrastructure (BGI) to enhance its performance and biodiversity. BGI, which combines semi-natural and engineered elements, offers benefits such as stormwater management, water purification, heat mitigation, and habitat provision. However, current BGI designs often prioritize engineering goals, neglecting their ecological potential. The authors emphasize the importance of species diversity, abundance, and ecological processes to improve engineering performance, resilience, and reduce management costs. They highlight the need for interdisciplinary collaboration to navigate trade-offs between engineering and ecological objectives, ultimately enabling the engineering of BGI that supports biodiversity. The article reviews the literature on the benefits of ecological engineering, focusing on terrestrial and freshwater BGI elements like green roofs, rain gardens, and constructed wetlands. It discusses how biodiversity affects BGI performance in terms of stormwater management, water quality, and heat mitigation, as well as resilience and maintenance costs. The authors argue that increasing species richness and functional diversity can enhance BGI performance and resilience, while maintaining high levels of biodiversity can also benefit human well-being through ecosystem services. The article also explores the trade-offs between ecological and engineering goals in BGI design and maintenance, emphasizing the need for systematic assessments to balance these objectives. It suggests that interdisciplinary collaboration is crucial for addressing challenges related to climate change and urban biodiversity, and calls for more research to understand and quantify the conditions under which nature can serve as an ally in BGI design and management. The authors conclude by urging engineers and ecologists to expand their collaborations to innovate effective and resilient BGI systems that can help mitigate environmental challenges in urban areas.The article "Engineering blue-green infrastructure for and with biodiversity in cities" by Kilian Perrelet, Marco Moretti, Andreas Dietzel, Florian Altermatt, and Lauren M. Cook advocates for integrating ecological and engineering objectives in the design of blue-green infrastructure (BGI) to enhance its performance and biodiversity. BGI, which combines semi-natural and engineered elements, offers benefits such as stormwater management, water purification, heat mitigation, and habitat provision. However, current BGI designs often prioritize engineering goals, neglecting their ecological potential. The authors emphasize the importance of species diversity, abundance, and ecological processes to improve engineering performance, resilience, and reduce management costs. They highlight the need for interdisciplinary collaboration to navigate trade-offs between engineering and ecological objectives, ultimately enabling the engineering of BGI that supports biodiversity. The article reviews the literature on the benefits of ecological engineering, focusing on terrestrial and freshwater BGI elements like green roofs, rain gardens, and constructed wetlands. It discusses how biodiversity affects BGI performance in terms of stormwater management, water quality, and heat mitigation, as well as resilience and maintenance costs. The authors argue that increasing species richness and functional diversity can enhance BGI performance and resilience, while maintaining high levels of biodiversity can also benefit human well-being through ecosystem services. The article also explores the trade-offs between ecological and engineering goals in BGI design and maintenance, emphasizing the need for systematic assessments to balance these objectives. It suggests that interdisciplinary collaboration is crucial for addressing challenges related to climate change and urban biodiversity, and calls for more research to understand and quantify the conditions under which nature can serve as an ally in BGI design and management. The authors conclude by urging engineers and ecologists to expand their collaborations to innovate effective and resilient BGI systems that can help mitigate environmental challenges in urban areas.