WHEN IT’S GONE, IT’S GONE: The Lorax (Danny DeVito), who is a defender of the Earth’s plant life, is horrified and saddened to discover that another Truffula tree has been cut down. He pleads with Ted, who cut the tree down, to talk to the Once-ler (Ed Helms, not shown), who then explains to Ted the importance of preserving the ecology of the Earth’s plant life by keeping pollution and deforestation in check.

Twelve-year-old Ted (Zac Efron) has a big crush on the girl next-door (Taylor Swift), so he makes up excuses to ring her doorbell just so he can see her. He finally realizes he actually has a chance with Audrey when she mentions that she’d marry the first boy who could bring her a real live tree.

She’s never seen one, because their hometown of Thneedville is an artificial environment where everything is plastic except for the citizens. What the children don’t know is that their idyllic community is also walled-off from the contaminated outside world that has been turned into a vast wasteland as a result of environmental pollution.

Intent on impressing Audrey, Ted asks his grandmother Norma (Betty White) where he might find a Truffula, the species of trees that once thrived in Thneedville. She suggests he seek out the Once-ler (Ed Helms), a reclusive elder who lives outside the city.

So, Ted hops on his scooter and drives out of town for the first time. He is shocked to see the widespread blight that he’s been shielded from his whole life. Also, it’s apparent that the desolation is due to the smog and sludge being spewed by an operation owned by Thneedville’s avaricious Mayor O’Hare (Rob Riggle).

Ted finally finds the wise old Once-ler who, in a series of sobering conversationss, teaches Ted a valuable lesson about the importance of protecting the environment from greedy corporations. And the Once-ler even admits to the role he played in the destruction of the forest when, over the objections of a tiny, planet-protecting creature called the Lorax (Danny DeVito), he harvested all the trees to make a quick buck.

Loosely based on the Dr. Seuss children’s classic of the same name, The Lorax is a parable about the importance of preserving the Earth’s natural resources.

While the movie’s dire apocalyptic message might scare some impressionable children, most of them will likely take it all in stride, especially with the film’s fairy tale ending.

Very Good (***). Rated PG for mild epithets. Running time: 86 minutes. Distributor: Universal Pictures.