Everything in the forest depends on many other things to survive. Upsetting this balance is a very destructive event for the tropical environment. It is not wise to upset the natural order of things in any ecosystem, but more so in the rainforests.
Life has become so finely tuned to its surroundings that by inadvertently over-harvesting a fruit, killing too many mammals or the use of dangerous pesticides can cause horrible knock on affects.
The Brazil nut. We all know it and it is a sustainable product of the rainforest (the forest stays intact whilst the harvest is collected). For the trees to pollinate it relies on certain large bee species. If you poison the bees there wont be any cross pollination. Or, if you kill too many tree snakes or other bird predators, then the birds over-populate and then they eat too many bees, so the affect is the same.
On the forest floor is a humble little rodent called an Agouti (genus Dasyprocta) which, like a squirrel, hoards nuts. The agouti is one of the only animals to be able to break into the tough exterior shell of the Brazil nut to get at the little ones inside. Then it makes little holes in the ground and buries some in each hole. It then forgets where some holes are and there we have the next generation of trees planted. It is obvious what happens if you over-hunt these creatures or affect the natural order of things.
The above is just one of millions of examples happening in the tropical regions of the world today.
