If I recall correctly the main problem for evaluating the amount of trees on earth is in the tress density of forest which may vary by quite a lot more than we

If I recall correctly the main problem for evaluating the amount of trees on earth is in the tress density of forest which may vary by quite a lot more than we initially believed. And of course that numbers can easily vary by a factor on 100 if you vary the criterion you use for counting a plant as a tree.