Tree planting has become a favored response to environmental loss. Governments, companies, and philanthropies announce large targets with reassuring round numbers. Forests, after all, store carbon, shelter wildlife, and support livelihoods. Yet the details matter. Planting the wrong species, or planting trees where forests did not exist, can undermine both biodiversity and climate goals.
That problem has become clearer as restoration pledges have multiplied. A 2019 commentary in Nature found that nearly half of the area pledged under the Bonn Challenge consisted of plantation-style monocultures. A 2024 study in Science showed that much land promised for reforestation in Africa…