New benchmark system aims to fix forest restoration’s biodiversity problem one year after launch

With approximately 60,000 tree species worldwide capable of storing carbon, providing food and shelter, and supporting countless ecosystems, forests represent one of our most powerful tools against climate change and biodiversity loss. However, a troubling pattern has emerged in major restoration efforts: too many projects are planting the wrong trees in the wrong places, undermining their environmental benefits.

Research has revealed significant flaws in high-profile restoration initiatives. A 2019 Nature study found that nearly half of the area pledged under the Bonn Challenge—which aims to restore 350 million hectares of degraded forest by 2030—was designated for plantation-style monocultures that provide minimal benefits for carbon storage or biodiversity. Even more concerning, a 2024 Science study discovered that half the land earmarked for reforestation under the African Forest Landscape Restoration Initiative was actually savanna, an ecosystem where tree planting can cause ecological harm.

“It started to occur to us that there was potentially a problem here, particularly given the size of the pledges that were being made,” explains Paul Smith, secretary-general of UK-based Botanic Gardens Conservation International (BGCI). In response to these widespread issues, Smith and his colleagues developed a new certification system focused specifically on biodiversity outcomes—filling a critical gap they identified in existing forest restoration standards.

This new benchmark system, known as TGBS (Tree Growers for Biodiversity Standard), has now been operational for one year and offers a framework to ensure forest restoration projects genuinely benefit local ecosystems rather than simply maximizing tree numbers.