We can all agree planting a tree is good for the environment — right? According to a recent study in Nature, the global crusade for reforestation as a remedy for climate change is largely missing the mark. So where did it go wrong? The new evidence reveals that most of the countries with large-scale tree-planting programs are actually developing tree plantations, which might help the economy but fail to sequester the carbon that the countries originally pledged to.

vibrant green trees and moss-covered ground

The Bonn Challenge promises 350 million hectares of trees

In 2011, the international Bonn Challenge was announced as an ambitious plan to plant 150 million hectares of trees by 2020. In 2014, more than 100 nations signed on under the New York Declaration of Forests, increasing the target to 350 million hectares by 2030. Unlike many lofty development goals, most countries are actually on track to exceed their promises, at least at first glance. In fact, the world actually has more forest cover now than it did in 1982. So, what’s the problem?

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Well, the majority of countries have been using the incentives and global momentum to back monoculture farms and counting trees that will be logged within years in their Bonn Challenge totals.

According to the assessment, 45 percent of trees planted were species that will be quickly harvested for paper production. Another 21 percent were tree farm species, like fruits, nuts and cocoa. Only 34 percent of trees planted were part of so-called “natural forest,” even though the original intention of the Bonn Challenge was that all hectares planted should be natural forest.

“Policymakers are misinterpreting the term forest restoration [and] misleading the public,” argued the study authors, Simon Lewis of Leeds University and Charlotte Wheeler from Edinburgh University.

While agroforestry trees do provide important benefits to the environment and economy, monoculture plantations (especially when farmers clear natural forests for crops) fail to provide anywhere close to the same benefit in terms of sequestration and biodiversity.

low-lit forest with sunlight barely streaming through tall trees

The value of natural forest

A general definition of a natural forest is a “multilayered vegetation unit dominated by trees, whose combined strata have overlapping crowns, and where grasses are generally rare.” In general, a natural forest will store up to 40 times more carbon than a plantation that is harvested every decade.

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More than just trees, forests are important and intricate ecosystems. They are home to incredible biodiversity and provide sanctuary and habitat for thousands of species. They are also critical to the climate, because forests maintain rainfall and prevent desertification. Because clouds accumulate over forests, places that have destroyed all of their major forests often experience low rainfall, drought, desertification and other climate-related issues.

aerial view of forest with parts deforested

Reforestation pledges around the world

Even before the Bonn Challenge, China launched a massive reforestation program in response to flooding along the Yangtze River. Despite over two decades of reforestation, the report claims that 99 percent of all trees planted have been within monoculture plantations.

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In Niger, after years of complying with foreign and government extension officers who advised farmers to remove trees, farmers have finally argued that native trees serve an important purpose right where they are. Trees stabilize soil, produce nitrogen, buffer strong wind and improve organic matter in the soil. As a result of the farmers’ knowledge, deforestation has decreased, although the majority of farmers now wisely plant trees that will supplement their incomes rather than simply sequester seemingly abstract carbon.

Yale Environment 360 reported that in Brazil, up to 82 percent of the forest restoration work is developing monoculture plantations and not natural forests.

sunlight streaming through rows of trees

How to plant a forest? “Get out of the way.”

According to National Geographic’s investigative article, “How to regrow a forest: Get out of the way,” even specific efforts by the U.S. Forest Department to plant natural forests have not worked the way they were intended to. For ease of planting and eventual use as lumber, the Forestry Department had a long-term tradition of planting native trees in neat rows at 12-foot gaps. Though the majority of trees were then left to develop into natural forests, the meticulous spacing has since exacerbated fire risk. The Department now opts for more irregular spacing and species biodiversity. Although it is more time- and cost-intensive, it ends up saving the department in firefighting costs later.

Similarly, in Canada, a study found that a government campaign to drain wetlands thought to be smothering spruce trees caused a fire that destroyed 2,400 homes in 2016. Under the pretense of growing larger trees to store more carbon, peatlands were systematically destroyed. However, it is now recognized that peatlands ultimately store enormous amounts of carbon naturally and were more resilient to fires.

“If you take the perspective that no matter what, more trees are better, that’s going to have unintended consequences,” said Sofia Faruqi from the World Resource Institute. “In the case of the West Coast, restoration may mean removing trees from the landscape.”

lush tropical forest

Turning over a new leaf on reforestation pledges

According to Faruqi, policies must acknowledge both what kind of tree is planted and how the tree “jibes with the larger health of the forest, the amount of water available or the needs of local people.”

As we approach the start of the United Nation’s declared Decade of Ecosystem Restoration, many forestry experts agree that reforestation solutions must be localized — both at a national level and at the individual forest level. While the need for income, especially sustainably sourced income, is paramount, cash crop trees should be planted in addition to the 350 million acres of natural forest.

Tropical forests are particularly important, because they have the potential to capture more carbon than any other forest type in the world. In many equatorial regions, where there are large amounts of land available and a high need for economic stimulation, healthy tropical forests can provide jobs, support indigenous traditions and capture an estimated 3 billion tons of carbon annually. That’s the equivalent of taking 2 billion cars off the road every year.

Blanket pledges of specific tree planting targets have not worked and leave the door open for damaging misinterpretation. More research and awareness is needed to understand the importance of different ecosystems and more priority given to protecting and keeping natural ecosystems intact. The idea that any tree planted helps is simply outdated and misleading.

A quote by American poet, environmentalist and farmer Wendell Berry sums it up nicely: “Say that your main crop is the forest that you did not plant, that you will not live to harvest.”

+ Nature

Via Yale Environment 360 and National Geographic

Images via Michael Benz, Marc Pell, Jesse Gardner, Janusz Maniak, Steven Kamenar and Zoer Ng