Creates a special tax rule for casualty-loss deductions when uncut timber is damaged or destroyed. It bases the minimum deductible loss on an appraisal (pre-loss value minus salvage value), requires appraisals within a year (with an option to elect an estimated value if delayed), covers pre‑merchantable timber and timber not held for sale, and requires reforestation within five years or repayment (recapture). The provision also lists additional events that qualify as casualties.