China appears to have turned the corner on deforestation.

Beijing implemented a forest conservation program in 1998. And we now have proof that it's working.

Logging and clear cutting shrank China's forests for decades, but from 2000 to 2010, the nation saw a net gain in tree cover, according to new data.

A team of scientists studied the nation's forests using satellite images, eyeing where tree cover expanded and decreased. Over the decade they saw significant recovery in about 1.6 percent of China's territory, while 0.38 percent continued to lose tree cover. Their findings are reported in a paper published Friday in the journal Science Advances.

"Before there was widespread deforestation," study author Andrés Viña of Michigan State University's Center for Systems Integration and Sustainability tells The Christian Science Monitor in an interview. "Now that has stopped and there is a net gain in forest cover."

Forests harbor immense biodiversity, prevent soil erosion, and act as carbon sinks – scrubbing the atmosphere of carbon dioxide.

Trees grow by taking carbon dioxide from the atmosphere and locking it away in their roots, trunks, limbs and leaves until they die and decompose, when the carbon is released back into the atmosphere. Currently, elevated carbon dioxide levels in the atmosphere are heating up the planet. Forests are key, natural tools in mitigating climate change.

But forests have lost some 319 million acres, an area just larger than South Africa, over the past quarter century. Conservation programs like the one in China are starting to turn those trends around.

China's conservation program

For decades, Chinese forests were ravaged by the timber industry and clear cutting to convert areas to farmland. Biodiversity was lost, and flooding and soil erosion became significant issues without these trees to maintain the balance in the ecosystem.

There was catastrophic fallout. Losses from flash flooding in the summer of 1998 alone reached $20 billion. In response, Beijing instituted the Natural Forest Conservation Program (NFCP).

The NFCP targeted sensitive regions that had been significantly degraded over the previous five decades, such as regions around the headwaters and other upstream portions of major rivers. A significant part of the NFCP has been extensive bans on logging in natural forests, instead shifting towards other timber sources.

From 1998 to 2000, the government had already invested over $2 billion in the conservation program. By the turn of the century, timber harvests from China's natural forests had been reduced from 32 million cubic meters (42 million cubic yards) in 1997 to 23 million cubic meters (30 million cubic yards) in 1999.

But that didn't mean China's thriving manufacturing industry was just going without timber. The nation now sees significant timber imports from places like Vietnam, Madagascar, and Russia, Dr. Viña says. "We think that success in reducing deforestation in China is basically being transferred into deforestation in other regions," he says.

"Over the long-term, sustainable forest management in China is important for forests in the rest of the world," says Robert Tansey, senior advisor for external affairs and policy in Northeast Asia and Greater China at The Nature Conservancy, who was not part of the study.

A global issue

"When it comes down to climate and carbon sequestration, these are global problems," Kevin Griffin, an ecologist at Columbia University's Lamont-Doherty Earth Observatory who was not part of this study, tells the Monitor in a phone interview.

But this study just looked at China's success in forest conservation. Dr. Griffin says, "When you analyze them on national levels, you have to be mindful of the fact that savings in one country might mean a loss in another one."

Viña agrees, "In this globalized world we need to go beyond national analysis. Now we have to go into international, cross-boundary analysis."

Worldwide, the picture is less optimistic. Forest cover in many regions is still shrinking.

Although global deforestation has yet to reverse course, reports do suggest it is slowing. In fact, global deforestation rates have been cut in half since 1990, according to the United Nations Food and Agriculture Organization’s Global Forest Resources Assessment (FRA). In the 1990s, an average of 0.18 percent of the world's forests were lost each year, but from 2010 to 2015, that average loss dropped to 0.08 percent.

"It is encouraging to see that net deforestation is decreasing and that some countries in all regions are showing impressive progress. Among others, they include Brazil, Chile, China, Cape Verde, Costa Rica, Philippines, Republic of Korea, Turkey, Uruguay, and Viet Nam," FAO Director-General Jose Graziano da Silva said in a press release in 2015.

And with decreasing deforestation, that means more carbon storage. The FAO also reported that carbon emissions from forests decreased by 25 percent from 2001 to 2015.

Big picture or whole picture?

Narrowing in on one nation isn't the only limitation to this new study of China's forests, Griffin says. Satellite images can examine overall tree cover, but the picture is a lot more complex than simply counting trees and net forest mass. Different tree species and different types of forests can sequester more or less carbon or provide habitats for a different set of plants and animals, he says. And they might not be just the same as the degraded forests they're replacing.

For example, a recent study, published in the journal Science, shows that an expansion of forests towards dark green conifers in Europe has increased, rather than mitigated global warming. The findings challenge the widespread view that planting more trees helps human efforts to slow the Earth’s rising temperatures. Apparently, not all trees have the same mitigating effect, reported the Monitor.

Although satellite imagery is "a really great tool to apply to a global problem" and the net increase in forest cover is a step in the right direction, the issue of regrowth is more complex than just simple snapshots, Griffin says.

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But generally, "knowing the status of our forests is super important," he says. "The forest provides an immense number of ecosystem services, everything from clean water and oxygen to habitat and biodiversity."

Mr. Tansey says, "Nature serves people's needs."