Another planet, green, lush, dangerous, the adults are afraid to go outside of the city, but the teenagers have forged a special relationship with the flora and fauna there.
The teens have bonded with animals from the jungle/forest, and perhaps I remember they developed a certain sense of danger/connection with the forest.
A teen boy is the main character, there is an "uncle" of some sort, a former marine, who lives outside the city.
I thought the story was names "greenies" or something like that, since I read it after reading Greenies, Accidental Martian, and other stories about Mars.
Does this jumbled description remind you of something? Searching hasn't brought me anywhere yet.