Wikipedia (with sources tha may or may not be better than the Daily Mail) says the average American uses about half a tree worth of toilet paper a year[1]. I don't know about the virgin forest bit, nor how hard it is to find toilet paper from recycled sources (it is one of the lowest grade papers, so I think would be easy to produce from recycled fibers).

If you're worried about the environment, some other possible resolutions: * eat vegetarian one day a week * vow not to drive for errands less than a mile away * switch to low-energy light bulbs

(Caveat: Un-sourced claim) I suspect any one of those would offer a benefit for mother nature at least an order of magnitude above not using toilet paper.

[1] http://en.wikipedia.org/wiki/Toilet_paper#Environmental_cons...