Fifty years after his only visit to Hawaii, the acclaimed author and conservationist Richard Powers is coming to the islands to speak and read from his new, best-selling novel “The Overstory,” a captivating, soaring epic rooted in the consciousness of big, ancient trees.

Powers has been invited as a guest of the Merwin Conservancy, founded by Maui resident, ardent conservationist and Pulitzer Prize-winning poet W.S. Merwin, twice a U.S. poet laureate.

That Merwin should invite Powers to the islands seems predestined. On the Conservancy’s website, Merwin is quoted: “On the last day of the world/ I would want to plant a tree.”

While researching “The Overstory” (2018, Norton), “I accumulated a massive arboretum full of poems, and there were so many of (Merwin’s) in there,” Powers said, calling from his Tennesee home.

A reader might also wonder if Powers’ visit could be a real-life outgrowth of a vast plan woven by the trees in his book.

In “The Overstory” Neelay Mehta, a Silicon Valley child prodigy, climbs a native black oak and finds in the network of its branches “the most perfect piece of self-writing code that his eyes could hope to see.” He will become a billionaire designer of virtual-reality games in which humans compete for mastery of the planet.

Meanwhile, California redwoods, possibly the oldest life on Earth, “work a plan that will take a thousand years to realize — the plan that now uses him, although he thinks it’s his.”

Local readers can learn more on Wednesday, when the National Book Award winner appears as part of the Merwin Conservancy’s Green Room lecture series.

Powers will also play an excerpt from a cantata based on Merwin’s poem “Trees.” Powers wrote it in collaboration with musicians and writers, including authors Joan Maloof (“The Living Forest”) and Bill McKibben (“The End of Nature”).

“THE OVERSTORY,” Powers’ 12th novel, was inspired by the astonishing sight of a towering, virgin-growth redwood tree, the author said. Powers spotted it as he hiked the coastal range above Stanford University, where he was a professor of creative writing. There he also found a bench dedicated to Wallace Stegner, the novelist, conservationist and essayist whose sense of place Powers long admired.

Now Powers said he was looking forward to meeting Merwin, another eco-literary writer, and visiting “some of the settings of his poems” on Maui, where Merwin and his late wife Paula Merwin planted a palm forest on 19 acres of former pineapple plantation.

The forest, which Powers called “extraordinary,” includes 3,000 palm trees of 480 species.

Several characters in “The Overstory” plant trees, starting with a handful of chestnuts picked in Prospect Park, N.Y., and found in his pocket by immigrant Jorgen Hoel after he moves to Iowa. He plants them on his farm.

The stowaway nuts may be part of the plan, for the surviving Hoel Chestnut, a solitary giant, will live more than a century, evading the American chestnut blight that “slips into the country from Asia, in the wood of Chinese chestnuts destined for fancy gardens.”

Botanist Patricia Westerford believes that trees communicate and take action, for instance secreting natural insecticides when pests attack neighbors. She observes that a 500-year-old Douglas fir, before it dies, “will send its storehouse of chemicals back down into its roots and out through its fungal partners, donating its riches to the community pool.”

But forests continue to dwindle, and she travels the world collecting seeds to preserve in a Colorado vault.

The dramatic heart of the book is the “Redwood Summer” of 1989 in Humboldt, Calif., when activists tried to stop clearcutting by living in the canopies of virgin giants, 200 feet above the ground.

In Humboldt, one of the tree-sitters is artist Nick Hoel, scion of the Iowa family. He joins forces with other core characters who, frustrated by continued logging, become arsonists and cause a tragic accident.

WHILE RESEARCHING “The Overstory,” Powers, like his characters, was transplanted by trees. The author, 61, crossed the country to see the East’s largest remnant primary forest, in Tennessee’s Great Smoky Mountains National Park.

“I’d visited old-growth forests before, but when I hiked up into Great Smoky for the first time, it smelled, looked and sounded different,” he said. “There was a quality of health I felt from breathing the air and walking the mountains I had not felt anywhere else.”

Months later, “I was still thinking about this place,” he said. So he left Stanford and bought a house on the edge of the forest.

Trees give us food, shelter and oxygen, and sequester carbon dioxide, the greenhouse gas. But if humans don’t understand that we should save them purely for themselves – and do it — we won’t survive, Powers said.

In “The Overstory,” the Hoel Chestnut moves generations of the farmers to capture it in daily photographs for 80 years; they have grown to love it for itself.

The photographs inspire Nick Hoel to become the family’s first artist and, later, a tree protector.

Some humans evolve.

“In non-Western literature and indigenous myth and legend, they knew that any story wouldn’t have us as a center but only as a part,” Powers said.

A driving premise of his book is that, if we can see ourselves as part of nature and stop trying to conquer it, we may save ourselves as a species and also escape our fear of death.

We can also heal our loneliness and alienation from nature. Another theme of Powers’ is that people and trees can become one.

As in the myths of Daphne, Baucis and Philemon, in “The Overstory” we see several of the book’s characters, including an old married couple who’ve weathered many disappointments, begin turning, at least spiritually, into trees.

His next novel, he said, looks into the future, exploring how to rehabilitate our relationship with nature before it’s too late.

In “Overstory,” the botanist Westerford wonders if anyone will be left in the future to plant her seeds. Powers still hopes to avert that unhappy ending.