Why a rainforest can't be replanted

Rainforests as we know are in very wet areas. The temperature and humidity are just right here for water to be constantly cycling through the ecosystem. Since water is the major chemical weatherer of soil, this means that these soils get "old" really fast. An old soil means that most of the minerals have been leached out or used up, and all that is left is the skeleton of the minerals that stick around forever. These aren't especially useful to plants, in fact some of them are totally useless to plants. So, this means that the trees that are there are well-established and adapted to living off of the nutrients that are cycling in the their ecosystem. The moisture level and temperature are perfect for supporting so many kinds of life, that they thrive on one another. Unlike most places, the plants and animals that die don't contribute their organic matter (Carbon) to the soil, they contribute it right back into the other plants and animals that come along and instantly consume it. The long and short of it is that planting a new tree in this environment is a pretty fruitless effort. And, since these forests have enormous carbon cycling capabilities, destroying them is like removing the Earth's lungs. People destroy them to make roads, convert land to agriculture and to burn as fuel, because they can't afford another source.

For more extensive information on raiforest issues and how our consumer choices affect them see: http://ran.org/issues/forests/