Efforts to save habitats around the world face this conundrum: Some of the most biologically rich forests are found in some of the world’s poorest countries.

Not only does that mean there’s immense pressure to exploit these forests for economic growth, but cash-strapped governments are often ill equipped to guard lands supposedly protected for conservation.

Consider Sub-Saharan Africa. The region is home to 20% of the world’s forests and 13% of species. Yet within protected areas there, scientists have documented steep declines in species, and the rapid loss of habitat to encroachment from activities like logging and farming.

In recent decades, African governments have formed new alliances with conservation groups to try tackle these problems, tapping into money and expertise from these non-governmental organizations (NGOs).

These alliances appear to give a significant boost to protection efforts, especially in some of the continent’s most vulnerable preserves. The direct involvement of NGOs in the management of protected areas has coincided with a more than 50% decrease in deforestation rates over the last two decades, compared with similar protected areas that didn’t have such an NGO presence, scientists reported last week in the Proceedings of the National Academy of Sciences.

“The effect is quite substantial,” lead author and environmental economist Sébastien Desbureaux of the Centre for Environmental Economics at France’s University of Montpellier wrote in an email to Anthropocene.

One of the first partnerships between a government and conservation group to oversee a protected area came in 1990, when the British-based Kasanka Trust worked with the Zambian government to manage Kasanka National Park. By 2014, 25 protected areas were run through similar partnerships in places as diverse as Mozambique, Malawai, Tanzania and the Democratic Republic of the Congo (DRC). Since then, the number of such arrangements has exploded to 122 on the land and five in the ocean, with roughly half the total in Madagascar.

While there are individual success stories for these partnerships, such as Virunga National Park in the DRC, Desbureaux wanted to see how this approach performed more broadly.

He and colleagues from Africa, Europe and the U.S. looked to satellite imagery tracking the fate of African forests between 2001 and 2023. They compared how the amount of forest standing inside protected areas run with NGO involvement changed over those years, compared to protected areas without an NGO presence.

The analysis revealed that overall, bringing in private partners to help manage or completely take over running a protected area made a huge difference. Places with an NGO involved lost, on average, about .14% of their forest each year, compared with .25% loss for similar areas overseen just by governments.

While changes of just a fraction of a percentage point might sound miniscule, it adds up to a lot over the scale of all the protected areas, noted co-author Antoine Leblois, also an environmental economist at the French center. The areas where NGOs were involved covered nearly 1 million square kilometers of land – roughly double the size of all of France. And that’s only one-third of the total protected areas in the region.

The effect was most pronounced in places where human pressure is greatest – meaning it’s relatively close to large concentrations of people. There, the scientists found NGO involvement cut deforestation rates from .39% per year down to .26%.

By contrast, the analysis revealed no significant difference in forest loss in remote protected areas far from most people. That’s likely because these forests face such low levels of deforestation, that any added protection would bring only small benefits.

The results suggest that working to establish such co-management deals are particularly worthwhile in places with lots of pressure from nearby towns and cities, even if those are some of the trickiest places to protect.

The benefits, the scientists write, may “become greater if NGOs are willing to take on the management of these tough contexts—and get donors to understand the higher associated risk of not succeeding.”

Desbureaux, et. al. “Collaborative management partnerships strongly decreased deforestation in the most at-risk protected areas in Africa since 2000.” Proceedings of the National Academy of Sciences. Dec. 30, 2025.