Made with Daft Logic's Google Map's Area Calculator Tool
Goldsmith has 3,000 cubic meters of space.
It takes 320 reams of paper to fill a cubic meter (four by four by 20 reams), and each ream weighs about 5 pounds. Each cubic meter therefore weighs 1,600 pounds.
So to fill the space takes 4.8 million pounds of paper, or 2,400 tons.
According to Conservatree, it takes about 24 trees per ton of printing and writing paper, again, “based on a mixture of softwoods and hardwoods 40 feet tall and 6-8 inches in diameter,” if they are processed “using the kraft chemical (freesheet) pulping process.”
So 24 trees times 2,400 tons nets 57,600 trees.
Now, forest density was a tricky one, so I deferred to the NHS Forest website, which claimed, “typical densities range from 1000 to 2500 trees per hectare.” I used the less dense side of the spectrum, because that was easier to calculate—57.6 hectares—then just converted to acres—getting 140.