The rules are reversed in gardening. We are positively encouraged to root out migrants such as Spanish Bluebells because they breed with our native Bluebells.
Chemical warfare is still very much allowed although the list of allowable toxins is cut every year. Instead, we are offered nice biological weapons such as nematodes that carry bacteria into the bodies of slugs and kill them.
But, dear gardener, come out of the garden and try any of that in the rest of the world and you're in trouble!