You just simply can’t.
Have you ever seen trees “eating” objects while growing? Hedges getting toys disappeared?
The evolution has done its best to let only those alive which will make all their best to make it.
Have a look on this picture. The fence will not stop this cactus to grow bigger. Well, I know the fence is not planted for that but it will also not be able to keep the boarder if this cactus is there. The plant is just gonna push it away. You can say – slowly – but it is only because you think and see in your time, have a look on it by the cactus time and you will see he is unstoppable.
People will never be able to fence the nature, all they can do is make something unlivable. But humans can do a “good” job in this also by their time. But not in LIFE’s time. If you build a huge wall to avoid life in a ground, life will also get stuck ONTO the wall. you will have to take a walk around the wall and remove all plants which are stuck on it already. You can kill but you cannot get into the way of life. Life is going on.
Just imagine, how much pain, heat and freeze, light and darkness did it have to survive to get to the Earth, survive again – impacting to the surface. And getting underwater – still surviving it – starting the new life.
People are no more than sharks – killers but they can newer kill all the fishes. There is always gonna be ONE – but only that one who could hide so well to wait until all sharks die in starving – this is the rule of life.
Our problem on the Earth is not the EXTERMINATION OF LIFE – but the extermination of people. This is what we do.