ATLANTA — The sprawling canopy of magnolias, water oaks and pines that earned Atlanta the nickname “The City in a Forest” is looking significantly thinner these days.

Giant hickories have fallen. Hundred-year-old oaks are dying. And thousands and thousands of less recognized trees have ended up in the woodpile after a brutal season that arborists describe as a perfect storm for this city’s famous leafy landscape.

In any city, people would carp about blocked roadways or damaged roofs. But in Atlanta, trees mean more. With 27 percent of the city covered with trees, Atlanta charges up to $1,000 to cut down a single one, even with permission. You need only flip through an Atlanta travel brochure, with its references to Peachtree Road or the Dogwood Festival, to understand why Jasen Johns, a city arborist, says, “Trees define Atlanta.”

That is also why the city’s self-described tree-huggers are so concerned that Atlanta is losing trees at an unusually rapid rate. The die-off has multiple causes: a severe drought, a series of powerful storms, a surge of invasive species and pests and the natural deaths of older trees planted during the creation of the city’s first planned neighborhoods in the early 1900s.