Historically, an ecosystem determined the numbers and survival of a population. Our life and health were at the mercy of nearby resources, predators, food, water, disease, weather, disasters, and natural phenomena.
As hunters and gathers, we depended on other populations of species for life. About ten thousand years ago we began to control our food through agriculture. We now engineer and control many aspects of our lives.
What does a given environment support? What do we need? What happens when we build systems that take care of people? What if almost everyone walks or bikes to work?
In order to be sustainable, we need to change our behaviors and adapt to what’s available. This is just as true for space colonization as it is for Earth.
What is the feasibility of sustainability for a unit of land? What is the variability from ecosystem to ecosystem or site to site?
Where can we place communities to maximize their self-sufficiency?
How much can we recycle in a given community?