Answer:
I think that the most important effect of deforestation is animal habitats being destroyed. This means so much for ecosystems all around the world, and any smallest change can bring have a large impact on the world. Many animals depend on trees for shelter or food, and destroying these habitats can wipe out many species of bugs or even birds. This may not seem like a such a bad thing because many people think of bugs as pests, but many animals like birds, frogs, and many other species would be greatly affected.
This is my view, and you may have a different view.