One could argue that Tolkien is an enemy to the trees. [Warning unverified sources and very rough maths lie below]

• The LOTR Trilogy has sold 150 million copies, and the Hobbit has sold 142 million source
• Each LOTR book has a (very rough) average of 430 pages, while the Hobbit has ~360. This totals to 115,620,000,000 pages printed
• The average tree creates ~20,000 sheets of paper source

This means Tolkien is responsible for the deaths of at least 5,781,000 trees. The Ents would not be happy