A forest has most of its trees cut down and it's full of sand. Did overpopulation most likely cause this condition or did deforestation cause this condition or high carbon dioxide levels or competition for water

Deforestation most likely caused this condition. Overpopulation may have contributed to the need for resources, leading to increased deforestation. High carbon dioxide levels could also be a factor, but it is more directly related to deforestation and loss of trees. Competition for water may be a secondary issue, but the primary cause of the bare forest and sandy conditions is likely deforestation.