In 1997, ecologists Daniel Janzen and Winnie Hallwachs contacted an orange juice firm in Costa Rica with an unusual concept. In exchange for contributing a part of pristine, wooded land to the Área de Conservación Guanacaste, a natural preserve in the country’s northwest, the park would allow the corporation to dump its unwanted orange peels and pulp in an intensively grazed, completely deforested region nearby, for free.

One year later, a thousand trucks came into the national park, unloading more than 12,000 metric tons of sticky, mealy, orange compost onto the worn-out plot. For more than a decade, the site went virtually unexplored. A notice was posted so that future scholars might find and examine it.

Sixteen years later, Janzen sent doctoral student Timothy Treuer to find the location where the food waste was placed.

Treuer set out to find the enormous placard that identified the scheme but failed.

“It’s a big sign with bright yellow text. We should’ve seen it,” Treuer adds. After wandering about for half an hour without success, he visited Janzen, who provided him more specific directions on how to find the plot.

Treuer was astounded when he returned a week later and proved he was at the correct location. Compared to the nearby barren former pastureland, the location of the food waste landfill was “like night and day.”

“It was difficult to imagine that the only variation between the two sites was a collection of orange peels. “They appear to be completely different ecosystems,” he explains.

Even though the area was densely vegetated, he couldn’t spot the sign.

Treuer and a team of Princeton University experts spent the next three years studying the site.

The findings, published in the journal “Restoration Ecology,” demonstrate how significantly the discarded fruit portions aided the area’s recovery.

According to the Princeton School of International Public Affairs, the experiment resulted in a “176 percent increase in aboveground biomass—or the wood in the trees—within the 3-hectare area (7 acres) studied.”

The ecologists compared the site’s varied attributes to an area of former pastureland directly across the access road where the orange peels were dumped two decades ago. In contrast to the next plot, which was dominated by a single tree species, the orange peel deposit location included two dozen different types of plants, the majority of which were prospering.

In addition to increased biodiversity, healthier soil, and a more established canopy, researchers discovered a tayra (a dog-sized weasel) and a massive fig tree three feet in diameter on the plot.

“You could have had 20 people climbing in that tree at once, and it would have supported the weight no problem,” says Jon Choi, co-author of the research and the one who did most of the soil analysis. “That thing was massive.”

Recent data shows that secondary tropical forests—those that emerge after the original residents are removed—are critical to slowing climate change.

In a 2016 study published in Nature, researchers discovered that such forests collect and store atmospheric carbon at nearly 11 times the rate of old-growth forests.

Treuer believes that improved management of wasted product, such as orange peels, might help these forests regenerate.

Deforestation rates are skyrocketing in many regions of the world, depleting local soil of vital nutrients and, with it, ecosystems’ ability to regenerate.

Meanwhile, most of the globe is overflowing with nutrient-dense food waste. Approximately fifty percent of all food products in the United States are wasted. The majority now end up in landfills.

“We don’t want companies to go out there will-nilly just dumping their waste all over the place, but if it’s scientifically driven and restorationists are involved in addition to companies, this is something I think has really high potential,” adds Treuer.

The next stage, he says, will be to see if other ecosystems—dry forests, cloud forests, tropical savannas—react similarly to comparable deposits.

Treuer returned two years after his original study to try to find the site’s sign.

Treuer has made over 15 visits to the property since his initial reconnaissance excursion in 2013. Choi had visited the site more than 50 times. Neither had seen the original sign.

When Treuer, with the assistance of the paper’s principal author, David Wilcove, and Princeton Professor Rob Pringle, discovered it behind a thicket of vines in 2015, the extent of the area’s alteration became obvious.

Choi describes it as a significant sign.

It was buried after 19 years of waiting with crossed fingers, thanks to two scientists, a stroke of inspiration, and the rind of an ordinary fruit.