Afforestation is the planting or replanting of trees in an area that never had trees or has not had trees for a very long time, such as thousands of years. This differs from reforestation, which is the replanting of trees on land that was previously forested.
The benefits of afforestation can include building habitats and ecosystems, reducing climate change via sequestration of atmospheric carbon dioxide, improving the quality of human health by absorbing pollution and dust from the air, improving topsoil, preventing the spread of desertification, reducing soil erosion, providing shelter from wind, improving water quality, increasing the supply of timber and other resources, and improving recreational opportunities.
The planning for an afforestation project can be complicated. Among the things that should be considered are (1) the specific reasons for creating the new forest, (2) whether there will be sufficient resources, especially water and topsoil, to sustain it, (3) whether it will be safe from predators, especially during the very vulnerable seedling stage, (4) which species of trees should be planted and their optimal mix, and (5) the possible effects on the ecology, water supply, climate and economy of surrounding areas.