One of the things that a lot of people are not aware is that you can not just expect a forest to occur because you leave land alone - it will eventually, but it could be many decades, if not longer.
This is because of the following factors:
1. Much of the mother trees have been lost - so there are no seeds available to start new trees.
2. Much of the fertility of the soil has been lost - or is unavailable to trees.
3. It will take more time than it might be given.
Rebuilding what as been lost normally takes a lot of work and patience. Under this topic I would like to discuss these three areas of concern, and possibly add some more.
Sometimes the land you have for reforestation hasn't had a tree on it for more than your life time. These will be more difficult to get started with.
If you use an example - if a forest fire goes through an area with trees, you will almost immediately start to see growth again of some trees within a year. Not all seeds are destroyed in a fire, in fact, some trees (Jack Pine) require a fire to be able to germanate.
But, if land has been used for pasture or crops for many years, it is possible that all of the seed is pretty much dead. This means to bring back biodiversity, you will have to import seedlings.
