Killing With Kindness - NYTimes.com By Michael Inouye and Sandy Keenan Hawaiian Roots: Armed with hatchets and herbicides, Paul Zweng and his volunteers thin a forest of invasive trees one section at a time. Their mission: to return the land to its natural state. WAIKANE, Hawaii - On days he can round up at least one volunteer to help him in his mission to restore native species to the forest, Paul Zweng commutes in an all-wheel-drive pickup from the home he shares with his wife and children in suburban Honolulu. Hugging the coast north toward the striking mountain terrain on the windward side of Oahu, he stops to pick up Sam or Charlotte or Jim. The regulars. At the Waikane Valley, he turns inland onto a muddy road, driving past the clapboard Church of the True God and a pig farm that welcomes visitors with an animal skull mounted on its entry post. The overgrowth thickens as he runs parallel to an old fence covered with warnings of unexploded ordnance, written in four languages. Only a fool or a feral pig would trespass here. Up a ways, he gets out and opens the gate to his 1,443 acres, which rise from tillable flatlands to tropical forests and a summit 2,600 feet above the Pacific. This land sits deep in the culture of old Hawaii. There are a number of archaeological sites here, as well as the remnants of very old taro farms. And signs posted around the valley, now faded, testify to more-recent history: "Keep the Country Country," they say, and "New City, What a Pity." Back in the 1970s, members of the Waikane Community Association blockaded the highway to keep bulldozers - and the onslaught of condos and suburbia - from encroaching on their rural way of life. Things became so sticky at one point that the governor stepped in and the state bought much of the land to limit development, becoming the leaseholder for many of the farms and homes, an unusual arrangement still in place. Contemporary versions of these signs denounce the previous owner of Mr. Zweng's land, who wanted to build a luxury golf course with all the trimmings. "I sure never want to see my name on one of those signs," said Mr. Zweng, 56, showing a visitor around. True, he has development plans of his own, but they're not the kind that anyone around here expected. Mr. Zweng envisions a day when some of his forest will be returned to the natural state it was in before 20,000 kinds of invasive plants and animals arrived, carried by explorers, tourists and indefatigable birds. He likes to point out that what he's attempting is much harder than the discipline known as forest management. "Here, we're recreating the native forest," he said. Ask him when the land was pristine enough to satisfy his botanical tastes, and Mr. Zweng answers without hesitation: "Back before Captain Cook arrived." In other words, sometime before 1778. If you have a mission of this magnitude, it helps to have funds to match. And Mr. Zweng is not short on funds. But this is a fairly recent development. For most of his life, he was an exploration geologist who scoured the planet - spending much of his time outdoors in places like Peru, Mongolia, Chile and the Democratic Republic of Congo - in search of fresh sources of gold, copper, coal and rare earths. At one point, when their three now-teenage children were very young, he and his wife, Carrie, who is now 52, lived at a Peruvian job site five hours from the nearest supermarket. But along with a Ph.D. in applied earth sciences from Stanford, Mr. Zweng had a knack for raising capital and enthusiasm. And with experience, he learned to follow his hunches about where precious resources were likely to be found. All of that paid off big when the two Canadian companies he was involved with - as the chief executive of one (QGX) and a founder and director of the other (Antares) - identified huge reserves of coal in Mongolia and copper in Peru. In 2008, QGX was sold for $265 million, and two years later, Antares was sold for $650 million (both figures are in Canadian dollars). For the first time in his life, Mr. Zweng said, "I had a nickel and a dime jingling in my pocket."