Justdiggit - TerraFund Verification Results

Project Snapshot

In Tanzania’s dry Singida region, overgrazing and intensive agriculture have uprooted millions of trees. The lifegiving soil of farms and rangelands is rapidly eroding, parching this unique ecosystem and making farming more difficult for the rural communities that depend on the land for their food and livelihoods.

In 2022, TerraFund financed Justdiggit, a non-profit organization that helps communities recover landscapes across Africa, to regenerate this critical ecosystem through the power of nature.

Justdiggit strengthens community organizations like Tanzanian partner LEAD Foundation to spread a technique called "Kisiki Hai," or “living stump” in Swahili. This "assisted natural regeneration" (ANR) approach helps trees regrow from the seeds and roots lying asleep in the soil, the remnants of past clearing campaigns. Rather than planting new seedlings, farmers carefully manage living tree stumps and naturally sprouting shoots so they can grow into mature trees.

Justdiggit's goal was to help farmers re-grow 67,000 native trees across up to 1,600 hectares. From the project's first year, community members were at the center. Justdiggit trained “champion farmers” in regeneration and sustainable land management techniques. In turn, they shared this knowledge with more than 2,100 farming households in Singida, building a movement stump by stump. As they saw the landscape regreen, farmers took direct ownership over the regrowing sprouts, helping them grow tall and strong. By eliminating the high costs of building nurseries or watering vulnerable saplings, the project could redirect budget to create formal jobs, employing 17 people in program coordination and field support roles.

Verified Results

The Target

Metric	Target	Reported
Trees Naturally Regenerated	67,000	167,500

The Analysis

The Results

Metric	Verified Result
Trees in March 2022	269,223
Trees in August 2024	414,577
Verified New Trees	145,354

It's a challenge to accurately count the number of growing trees in a natural regeneration project, even when the results are clearly visible when visiting the site. On a typical planting site, trees are put in the ground at the same time and out in the open. But on natural regeneration sites, some trees start growing faster and others slower, some grow in the open and others under a mature tree canopy. This often leads to a lower number of new trees in a project's early years and major gains the longer that communities manage a project.

With this data, WRI tested whether its method for verifying newly grown trees can apply to this underinvested but critically important type of restoration project. WRI applied its AI-powered tree count methodology, powered by the DINOv2 computer vision model, to independently verify the reported data. WRI also validated these insights through a field visit to gather perspectives from the technical staff and the farmers themselves.

Justdiggit reported that the project had started to regrow 167,500 trees in the 2.5 years after the project began. Typically, WRI verifies the number of “trees grown” by multiplying a project’s total number of trees planted by the reported survival rate. Because Justdiggit's partner farmers restore trees by pruning existing stumps and natural shoots rather than planting new seedlings, the project does not track the "survival rate." The number of "trees grown" that monitoring experts verify is simply the number of newly sprouting trees that the project reported.

WRI analyzed satellite imagery of the project’s mapped restoration areas, known as "polygons." Justdiggit submitted 113 polygons covering 331 hectares, significantly fewer than the original target. This difference reflects earlier guidance from TerraFund, which asked projects to submit only a sample of polygons per site.

Within the 40 polygons where suitable satellite imagery was available, our analysis detected 5,383 new trees. We then extrapolated these findings across the 113 submitted polygons, resulting in an estimated 29,943 new trees detected within the mapped project areas. Assuming that these results hold true across all of Justdiggit's sites, WRI estimated that 145,354 trees are now growing across Singida, 87% of Justdiggit's own estimation and 116% higher than the original target.

These findings represent early insights into the project's long-term outcomes. Ecosystems naturally regenerate gradually, and monitoring will continue for three more years until the trees are fully mature.

WRI's Assessment

What’s Working

Justdiggit’s project demonstrates how ANR can mobilize large numbers of farmers to restore land using simple, accessible techniques. By encouraging farmers to regenerate trees from existing stumps rather than planting new seedlings, the approach reduces costs while allowing restoration to take place directly within working farmlands. The program’s use of “champion farmers” to train others has also proven effective for spreading restoration practices across communities, helping local people own the regreening process and integrate it into everyday farming activities.

What's Challenging

Monitoring ANR is challenging, especially when geospatial data is incomplete. WRI's analysis relied on the polygons that TerraFund asked Justdiggit to submit, which represent only a portion of the area that communities are restoring. The smaller the area is, the weaker the statistical extrapolation. To control for that challenge, TerraFund now requires projects to collect polygons for 100% of the planted area. Trees can also take longer to appear on a restoration site, especially within the first few years of a project, making it more difficult for project implementers and portfolio managers to shift strategies.

Pathway to Scale

The project offers several lessons for scaling community-led assisted natural regeneration projects, which are becoming increasingly important given their lower cost and focus on native species. First, high-resolution satellite data can help verify the outcomes of ANR projects when trees are growing in open-canopy ecosystems, a technological breakthrough.

Second, Justdiggit is an organization with deep experience in ANR, but many local organizations eager to embrace natural regeneration don't know how to collect accurate data. WRI is working with experts across Africa and in Brazil to develop a standardized system for setting targets and reporting standards for the number of "trees grown" in natural regeneration projects.

Third, with better data, financiers can get the best bang for their buck by encouraging local organizations to prioritize natural regeneration techniques wherever communities are ready — and roots sit sleeping under the soil.

_{Cover image credit: Justdiggit/TerraFund}