By Elisabeth Malkin

New York Times

UAXACTÚN, Guatemala >> Deep in the jungle, where the forest canopy bends sunlight into a lattice of overlapping greens, where jaguars glide and the throaty cries of howler monkeys resound over the birdsong, sits a sawmill that slices giant mahogany logs.

Ominous as the scene may look, the mill is part of a conservation strategy to preserve the forest.

The forest’s survival, indeed the endurance of forests across the tropics, whether in Brazil, the Congo Basin or Indonesia, offers benefits far beyond national borders. By absorbing carbon dioxide and trapping carbon, forests play a vital role in reducing greenhouse gas emissions.

On that, there is little disagreement. Yet it has been much harder to reach a consensus over how to fend off the threats encircling them. Cattle ranchers, farmers, illegal loggers and drug traffickers all lay waste to forestland, virtually immune to government efforts to protect it.

The experiment here in the Maya Biosphere Reserve in Guatemala’s northern Petén region suggests one solution: The most effective way to protect forests is to give control of them to the communities who already live there.

Those who can secure a living from the forest, often by harvesting valuable hardwood trees, have an incentive to protect it, and that can create a far stronger line of defense than what governments can muster.

“Nobody is going to take care of somebody else’s house, somebody else’s garden,” said Marcedonio Cortave, who directs an alliance of the communities working in the reserve. “But they will look after and defend their own livelihood.”

Communities and two local companies manage almost a quarter of the territory across the 5.2-million-acre reserve here, in 11 government concession areas that permit strictly monitored forestry. Some 15 years since the concessions were established, the deforestation rate in the managed areas is close to zero, according to a March study led by the Rainforest Alliance.

“If the concessions didn’t exist, the zone would be one big cattle pasture,” said Wilson Martínez, the forest manager for Yaloch, a concession area near the border with Belize.

Map in hand, he walked through a patch of jungle that had been harvested last year. Each tree had been plotted to determine which ones to cut and which ones to leave as seed trees.

All that betrayed the logging was the stump of a single mahogany tree, a modest clearing planted with mahogany seedlings, and faint trails. The site will be left to regenerate naturally.

Along with preventing deforestation, the communities have also succeeded in protecting the most threatened tree species in the jungle, native bigleaf mahogany and Spanish cedar, according to a study released this month.

“These practices represent the state of the art for conservation,” said Bryan Finegan, a forest ecologist at Catie, an international research institute in Costa Rica that led the study. “It’s a model for the world.”

Despite long-held doubts that communities are capable of sustaining their forests, international conservation groups have signed on to the strategy. Working with indigenous and community groups, they will press to include forest peoples’ rights in negotiations at the global climate change summit in Paris that begins Monday.

“The foresters and the technocrats say that they can’t manage their forests,” David Kaimowitz, the director of natural resources at the Ford Foundation, said. “But everywhere they have been given an opportunity to do that, that has not been true.”

That is clear in Uaxactún. Many of its 180 families first settled here more than a century ago to tap natural gum, or chicle, from indigenous trees. Among the wooden houses and thatched roofs of the tidy village, hints of new prosperity can be seen. Motorcycles lean against many front gates, used by the men who go into the forest to gather xate, a palm leaf exported to the United States for flower arrangements.

Sales of wood from the community’s forest concession area built the school, and there is scholarship money for students who want to study abroad. “They support you so you can come back and help your community,” said Carolina Alvarado, who studied environmental technology at a community college in Wisconsin and now helps run the xate project.

From the top of the high tower near Uaxactún, where lookouts watch for forest fires during the dry season, conservation seems assured. The lowland tropical forest ripples to the horizon over the lands that were once the heart of the Maya empire.

Yet at ground level, the battle is constant, and not all of the reserve has withstood the assault.

Asserting government control means challenging many powerful interests opposed to conservation, said Eliseo Gálvez, the deputy executive secretary of the government’s National Council of Protected Areas.

“Now it is even more complex because of the influence of illegal actors” who are using the park to move migrants and drugs north, he added.

For years different parts of the government, such as judges and the forestry police, have failed to coordinate, he said, although that has begun to change in response to a national anti-corruption drive.

Some 30 percent of all tropical forests worldwide are either owned or managed by indigenous or community groups, said Andy White, the director of the Rights and Resources Initiative, which lobbies for that number to grow.

“The governments and environmental organizations still have the flawed notion that the way to conserve forests is to create a park and throw everybody out,” White said.

Much of the western Maya Biosphere Reserve has been set aside as parkland, where the government is presumably in charge of protection, but that land has suffered the most deforestation, the Rainforest Alliance said.

“When the land belongs to the state, people think they have the right to take everything; it’s ungovernable,” Cortave said.

In the concession areas, the situation is the reverse. Communities patrol the areas under their protection to deter illegal logging, hunting and looting from Mayan archaeological sites.

Their constant vigilance is paid for by sales to widening markets. Rather than sell to middlemen, the communities have preferred to market wood directly to American guitar makers and other businesses, including Leroy Merlin, a European home-improvement chain.

The Wildlife Conservation Society is buying wood from Uaxactún for the Bronx Zoo and the New York Aquarium. The organization is also part of a coalition urging New York City to replace the wood on the Brooklyn Bridge’s aging walkway with a hardwood called manchiche from Uaxactún.

Helping the concession areas thrive costs money; the U.S. Agency for International Development has contributed an estimated $50 million since the biosphere reserve was established 25 years ago. But a study this month by the World Resources Institute argues that the price is a small fraction of the benefit the forests deliver in easing the effects of carbon emissions.

Not all places have had the same success as Uaxactún. Communities in three areas have lost their concessions, the shorn hillsides evidence of the inability to withstand outside pressure.

To the east, illegal loggers from Belize slip over the border at night during the rainy season when downpours mask the clatter of chain saws. “If the government had been more intelligent in the past, there would be more forest in the Petén,” said Manuel Burgos, 51, a guard and firefighter in the Yaloch concession.

Many here see Guatemala’s government as an enemy and protector. There are concerns that business groups with interests in the region’s petroleum deposits or in expanding oil palm plantations could sway the new government that takes office in January.

Yet the government forest technicians work closely with the communities, and security is improving. Now, soldiers and the police are based at a small camp on the only access road into the reserve’s eastern forest.

Just after dawn one day earlier this month two young men took chain saws to the trees on a hillside just outside the Yaloch limits, seemingly oblivious to how far the noise would travel.

One of them said he was clearing land for pasture, but admitted that he had neither cattle nor money to buy cows.

As he spoke, a slender tree gave way to the notches the pair had made and slowly fell. Then the police urged the men into a pickup truck, and they drove off.