To protect biodiversity we shouldn't even be touching the ecosystems. Everything us humans touch, is affecting it in one way or the another. If you cut down a tree, birds that nest there will have to move away so the rat population would increase. If they increase then the snake population would increase, etc.
Another way would have to be pollution. Our natural water resources are growing scarce and we are going to have to rly on an alternative very soon. When we pollute water we are killing the life inside that body. The fish will die so then the predators will be unable to eat. Then they will die, and there predator will not be able to eat. Biodiversity is very important in keeping our community alive.
Hope I helped. :)