Planting trees can reduce carbon emissions, but it can also cause ecological crises! Recent research suggests that large-scale reforestation projects in Africa may be misidentifying savannas and grasslands as forests, leading to the planting of trees in these areas. The increase in trees on grasslands could reduce food availability for herbivores or make them more vulnerable to attack, disrupting the balance of the ecosystem.
Study: Misclassification of forests and planting of wrong trees trigger ecological crisis
AFR100 is the abbreviation for the African Forest Landscape Restoration Initiative. This initiative was launched at the Paris Climate Conference in 2015. It aims to restore the landscape of 100 million hectares of land in Africa by 2030[1]. Projects include afforestation, promoting sustainable agriculture, and reducing chemical fertilizers. Over the past seven years, the number of participating countries has increased from 21 to 34, and the land area committed to joining the action has also increased to 130 million hectares.
However, a study published in the journal Science in February found that as much as 52% of the land included in the AFR100 tree planting project is not classified as forest, but rather as open grassland. Mistakes in definition and classification may have led to the planting of a large number of trees on grassland, affecting an area of more than 60 million hectares, an area larger than the size of France.
The study, published jointly by British and Dutch researchers, was led by Kate Parr, a professor of tropical ecology at the University of Liverpool in the UK. She noted, "Ecosystem restoration is essential, but different ecosystems require different approaches."
He said the definition of forest should be revised as soon as possible to avoid confusing woodland and steppe with forest. The increase in trees will be detrimental to the ecological integrity of woodland and steppe.
The Guardian reported that according to the Food and Agriculture Organization of the United Nations (FAO), land covering an area of more than 0.5 hectares, with trees over 5 meters tall and a canopy cover of more than 10% meets the definition of "forest". Therefore, open grasslands may be considered forests and become the target of tree planting projects.
Open grasslands are home to herbivores such as rhinos, wildebeests, and giraffes. They must remain constantly alert to avoid predators. The vast grasslands help them detect danger and escape quickly, increasing their chances of survival. Too many or too few trees can be a major threat to their survival.
Planting trees in open woodlands presents other problems. The tree canopy blocks sunlight, which in turn changes the vegetation on the ground. This means herbivores have less grass to eat, and the type of grass changes, too, with potentially serious consequences.
AFR100: The plan focuses on agroforestry
The latest research not only points out the consequences of incorrect forest classification, but also finds that up to 60% of the trees AFR100 plans to plant are not native species and may harm the local ecology.
Planting the wrong tree is not a new problem. Deutsche Welle reported in 2021 that Kenya introduced Prosopis juliflora to reduce sandstorms and provide wood for cooking and animal pens. However, heavy rains in 1997 caused the tree to spread rapidly, becoming a dominant alien species, crowding out native plants and ultimately depleting local animal food.
In response to the scholars' harsh accusations, The Verge specifically asked AFR100 about the issue. AFR100 clarified that its plan covers a wide range of areas, and that it is incorrect for the scholars to count all promised land as areas for future tree planting.
The World Resources Institute (WRI), one of the initiators of AFR100, also stated that the "vast majority" of AFR100 projects are agroforestry. Planting trees on farmland helps improve soil fertility, conserve water, and reduce soil erosion. However, Pal countered that planting trees on non-forested land does not count as ecological "restoration."
Social media giant Meta and the Bezos Earth Fund both support AFR100. When asked about the issue of "planting the wrong tree," the Bezos Earth Fund responded, "We've enjoyed our partnership with AFR100 and have funded over 150 local projects." Meta did not respond to media inquiries.
Editor’s note
[1] The word “restore” has two meanings: “recovery” and “restoration”. Traditional ecological definitions of “restoration” are strict; “planting trees” on farmland cannot be called “restoration”. However, the scope of the AFR100 project is broader, encompassing agroforestry, afforestation, restoration, and assisted natural succession, hence the translation of “restoration”.
References:
*AFR100 official website
*The Guardian (2024/02/15), Ill-judged tree planting in Africa threatens ecosystems, scientists warn
*Science (2024/02/15), Conflation of reforestation with restoration is widespread
*The Verge (2024/02/16), A Big Tech-backed campaign to plant trees might have taken a wrong turn
* Deutsche Welle (2021/03/25), When planting trees does more harm than good
* University of Liverpool (2024/02/15), ‘Misguided’ reforestation programs could threaten vast areas of tropical grasslands
Source: Environmental Information Centre
