The city is an ecosystem

Cities aren’t like ecosystems, they are ecosystems – their histories, their present states, and their future trajectories are all shaped by fundamental ecological principles, and therefore, understanding what was here before, what is here now, and what will be here tomorrow and beyond requires an understanding of how urban ecology works:

https://www.bostonglobe.com/ideas/2014/11/07/the-city-ecosystem-pipes-and-all/HjLVemBs9nPiuE53PjPSLK/story.html