One of the largest tree die-offs in California history, which has turned evergreen forests into a bleak canvas of oranges and browns, appears to be subsiding after nearly a decade of wreckage. New data from the U.S. Forest Service shows that the number of trees that perished in California last year hit a 10-year low. The 6.6 million trees counted as dead is still above normal, scientists say, but it marks a major letup in the run of drought, bugs and disease that’s decimated forests across the state. The epidemic peaked in 2016 with 62 million dead trees. The improvement, revealed in the preliminary results of Forest Service aerial surveys, is credited to wet weather. … Healthy forests are vital, notably for ecosystems, water supplies, carbon storage and communities reliant on forest recreation and the timber trade. Large numbers of dead trees can also increase the risk of wildfire.