“The Overstory,” by Richard Powers, a sprawling epic about the wonderful life and alarming death of trees, has won this year’s Pulitzer Prize for fiction.

The award marks a new high point in the growing prominence of environmental novels.

Powers has long been celebrated for his ability to explore complex scientific issues in the context of fiction. His previous novels have dealt with genetics, pharmaceuticals and artificial intelligence. In 2006, his novel about neurology, “The Echo Maker,” won a National Book Award and was a finalist for the Pulitzer.

“For me, this is a marvelous late-career recognition,” Powers said by phone just after he heard the news. “It’s my 12th book, and I’ve been writing for over a third of a century, so there have been ups and downs, and it’s a marvelous reward for staying the course. But perhaps for environmental fiction, there’s a little bit more to it. This is one of the chief literary recognitions that this country gives out, and it’s been given to a book that wants above all else to take nonhumans seriously and to take our relationship with those outside of the human world seriously. And that’s encouraging.”

But Powers described the current state of the environment as “a desperate moment.”

“I can’t help thinking that some of the appetite for this book and some of the response has been the result of people who need to think some other way about a world that we’re running through very quickly,” he said. “At a moment when we seem to be running in exactly the opposite direction than the one we need to be heading in, there are readers out there who are hungry for a story that re-connects us to this world that we’re so alienated from.”

“The Overstory” is a complex novel that begins with several apparently unrelated stories about people throughout the country and across the centuries: There’s a Norwegian immigrant who travels to Iowa and begins homesteading before the Civil War. There’s also a video game pioneer, an intellectual-property lawyer, an amateur actress and a soldier in the Vietnam War whose life is saved when a 300-year-old banyan catches his body falling from a plane. “He owes his own life to a tree,” Powers writes.

That, in short, is the point of “The Overstory”: We all owe our lives to trees, these massive air purifiers and soil conditioners that have made human civilization possible.

Among Powers’s enormous cast of characters is an innovative botanist who revolutionizes her field in the 1960s by suggesting that “trees are social creatures” that can communicate with each other and react to their environment. Though initially scorned by her colleagues, she lives long enough to see her ideas become accepted — even as the woods she adores are increasingly imperiled around the world.

Powers said this scientist was a composite of several people who have inspired him: “I’d like to think that she is a kind of proxy or emblem for a whole lot of people out there who, when you say the phrase ‘the real world,’ don’t think immediately of the fake world that we humans have created but are dedicating their lives to understanding this place that we need to make our home and that we need to understand if we have any desire to stay here for much longer.”

Environmental fiction is not new, but it has attracted more and more critical acclaim during the past decade. T.C. Boyle, Annie Proulx and Lydia Millet have all published urgent, compelling novels that describe the plight of Earth and call for more radical efforts to save the environment.

“If this prize has any meaning for me,” Powers said, “it’s not for this book alone but for a push among those literary writers who want to broaden our scope of concern from the personal and the domestic to the environmental and everything that lies beyond the world that we’ve created.”

“The Overstory” was one of the most widely praised novels of 2018. The Washington Post chose it as one of the top 10 books of the year. It is also a finalist for the PEN/Faulkner Award, which will be announced later this month in Washington.

Ron Charles writes about books for The Washington Post and hosts TotallyHipVideoBookReview.com.