New research tool helps donors navigate the murky world of tree-planting organizations

Tree planting has become the go-to solution for everyone from corporations chasing “net zero” goals to philanthropists seeking measurable environmental impact. But behind the feel-good imagery of saplings and success stories lies a troubling question: which reforestation organizations actually deliver on their promises?

University of California, Santa Cruz environmental studies professor Karen D. Holl encountered this problem repeatedly. “I would give talks, and people would ask, ‘Who should I donate my money to?'” she told Mongabay. “There was really no standardized way to answer that question.” The lack of transparency in the reforestation sector left well-intentioned donors guessing about which groups were genuinely effective.

To address this knowledge gap, Holl and postdoctoral researcher Spencer Schubert spent a year analyzing more than 125 intermediary reforestation organizations—the groups that channel most global tree-planting funding to local projects. Their research now powers Mongabay’s Global Reforestation Organization Directory, a new tool that allows users to compare organizations based on four key criteria: permanence, ecological soundness, social benefit, and financial disclosure.

Rather than ranking organizations, the directory presents standardized information about each group’s transparency and adherence to scientific best practices. The researchers verified whether organizations publicly share monitoring protocols, tree survival data, and financial reports, though much information still relies on self-reporting. While the directory doesn’t provide definitive verdicts, it offers donors and supporters a much-needed roadmap through what has long been an opaque and sprawling sector where many organizations claim to restore forests, but fewer provide evidence of their actual impact.