“Heartbreaking” is the word arborist Virginia Hayes-Miller uses to describe the tree damage the Aug. 10 derecho left behind in Cedar Rapids and much of Iowa.“It will take 30 years or more of consistent work to rebuild the tree cover that was lost in one storm,” she said.Miller, a certified arborist at Acorn ArborCare in Iowa City, and her co-workers have been cleaning up storm damage for the past eight months, and they’re still getting calls.“A lot of people are scared of the trees that are still standing in their yard, scared that their remaining trees will come down in the next storm,” she said.