It depends if you have actual damages.
To the extent their activities decrease your property value, the money is tax-free but you reduce your cost basis, which may increase your taxable capital gains when you sell. You may also need a before and after appraisal to document the lost property value.
If the activities do not reduce your property value (because the area affected is insignificant, because nobody would probably notice a few trees in the corner of the lot, and so on) then all the money is taxable.
