Last summer, a revolution occurred in Los Angeles landscaping: Across the city, tens of thousands of homeowners tore up their water-thirsty lawns and replaced them with gravel, turf, decomposed granite and a wide range of drought-tolerant plants at a rate never seen before.

The water-saving benefits of this massive landscape overhaul are undisputed — and that’s important in a region that was facing the worst drought in 1,200 years. Still, some experts warned that Angelenos’ zeal to use less water in the backyard would ultimately make the city warmer.

Dave Edwards has hiked in the Santa Monica Mountains for decades, but the view has changed in the past few years. Hundreds, if not thousands, of trees have died, leaving hillsides with gray and brown patches. Five years of drought has shortchanged trees on water and nutrients. Trees dried out and insects moved in. “It’s not just in the Santa Monica Mountains. It’s all over the state,” said Edwards, a volunteer with the Santa Monica Mountains Trails Council. “I have never seen it like this.”