This is conpletely serious but definitely a crank answer:
Create a network of Greenways on the scale of our railroads and interstates, carving out huge swaths of cities and connecting every state and national forest and park.
Then maintain the ecological integrity of these Greenways by making practical indigenous land management and foraging mandatory topics in schools.
I will also maintain a small army of engineers to run clean, running water through the greenways (for handwashing) as well as an army of pilots and EMTs to make sure the Greenway dwellers have access to modern medical infrastructure.
Again, I am completely serious.