Machete in hand, Chuck Chimera stalks the tropical rain forest looking for miconia, an imported tree once prized for its huge velvety green and purple leaves and sweet berries but now dreaded as "the green cancer."
Through the dense vegetation, he spots a 25-foot specimen about to burst into fragrant flower. With nearly 50 blows of the machete, he takes it down, a small victory in the fight to keep the towering plants at bay."In one year, that size tree could produce 20 million seeds," says Chimera, 26, a research associate with the National Biological Service. "And that's not the biggest one we'll see either."
Capable of shrouding the forest in perpetual near-darkness, the prolific miconia not only crowd out native plants but threaten Hawaii's water supply by shading out sponge-like mosses that keep rain from running off. They also overtake deeper-rooted native vegetation that help prevent erosion.
The struggle against miconia is but one battle in a desperate fight to save Hawaii's fragile environment, one that is being fought on two fronts: the battle against alien species, like miconia, and the effort to bring back endangered native species, including the Hawaiian crow.
When humans first arrived here 1,500 years ago, these isolated volcanic islands were home to more species of unusual plants and animals than the Galapagos Islands that later would so intrigue Charles Darwin.
Today, Hawaii has more native plants and animals on the brink of extinction than any other state in the nation, and more invading species than it can keep up with. The 728 square miles of Maui alone, where up to 400 inches of precipitation a year fall in the high-altitude rain forests, is home to 83 endangered species and countless alien plants and animals.
The battle lines are everywhere - in the tropical rain forest, the state agriculture department's quarantine station, the Honolulu airport baggage claim section.
The effort enlists not only researchers armed with machetes, but also agricultural inspectors who confiscate purple coconut crabs being sold for food and other illegal nonnative animals and plants, as well as a corps of beagle dogs trained to sniff luggage, packages and planes for fruits, vegetables or the prolific brown tree snake that has already invaded Guam.
It's not just Hawaiians who should be concerned, says Larry Nakahara, plant quarantine manager for the state Department of Agriculture. If brown tree snakes make it to Hawaii, for instance, they can just as easily hitch a plane ride to the mainland and start decimating bird populations there, as they have done on Guam.
"Think of the large poultry industry" on the mainland, Nakahara says. "The problem is real. This is not made up. This is not science fiction."
Perhaps the most graphic illustration of how easily an alien species could make its way to the islands occurred this spring, during the first modern recreation of the Polynesians' 2,000-mile voyage to Hawaii in traditional double-hulled boats, with only the stars and wave patterns for navigation.
About 12 days into the trip, crew members were being painfully bitten by nono flies, tiny insects similar to no-see-ums. The boats made an emergency stop 100 miles from shore, and the crew radioed for advice.
"The minute it was announced, it made headlines every day. There was a lot of effort to link having nono flies to the tourist industry. Imagine the economic impact if they were on the beach," says Pi'ikea Miller, an apprentice navigator on board who also works for the Nature Conservancy of Hawaii. It was she who first recognized the potential menace of the flies.
The crew threw overboard the fruits they had been given when they left the Marquesas Islands, scrubbed every nook and cranny of the wood-and-fiberglass boats and dragged the sails through the ocean water to kill any larvae. As an extra precaution, a Coast Guard plane dropped off cans of pes-ti-cide.
Finally, after about a day and a half of scrubbing and spraying, the boats were allowed to come ashore. But rather than stopping at several Hawaiian islands as planned, the boats were allowed to land only in Hilo, a small town on the Big Island of Hawaii. There, the six 60-foot boats were fumigated.
While the biting insects' landing would have been accidental, some alien species - the miconia, the wild boars and the Axis deer that eat vegetation and threaten the native forest - were intentionally introduced, before their threat was recognized.
Most of Maui's seven identified colonies of miconia have been traced back to botanical gardens or landscapers who cultivated the "velvet trees" for their appealing purple underside.
In their native habitat of Central and South America, the fast-growing miconia is kept in check by other, equally quick-climbing vegetation. But on Tahiti and Hawaii, miconia soon overshadow everything else, reaching heights of 40 feet and growing at altitudes as high as 6,000 feet above sea level.
Art Medeiros, research biologist with the National Biological Service on Maui, says he had been skeptical that miconia could pose a danger until he visited Tahiti, where the phrase "green cancer" was coined.
"It completely reshaped my way of thinking about how one species could dominate an ecosystem," he says. "We want to stop miconia because we want to prevent an environmental catastrophe."
Miconia are now Hawaii's No. 1 worry among thousands of alien plants - a bigger threat than the strawberry guava or the banana poka - because of their size and fecundity. They are also a major target because officials think they may yet be stopped.
The eradication effort includes not only felling trees and uprooting seedlings, but also spraying herbicides from helicopters or injecting them into the base of the trees, as well as searching for miconia's natural weaknesses.
One hope is that there might exist an insect from Central and South America that eats only miconia, but a recent attempt to bring in candidates for testing failed; Los Angeles airport quarantined the package for so long that the insects died.
As Chimera strides through the lush vegetation on the way to Maui's biggest miconia colony, the former premed student from upstate New York describes how miconia has fooled people before.
Several years ago, he says, officials thought they had stopped miconia, after workers and volunteers chopped down or pulled up an estimated 15,000 plants in Helani Gardens in Hana, on Maui's east coast. Then two years ago, a state official doing an aerial survey over the area spotted huge miconia trees shooting through the native forest canopy.
"We've got to keep on this," Chimera says. "There are so many battles in Hawaii. This is one we're at a point where we can still make a difference."