In the mid-1990s, 1,000 truckloads of sticky orange peels and orange pulp were unloaded onto a barren piece of land in a Costa Rican national park. Today, that same barren land has been transformed into lush forest.
The story starts with husband-wife team Daniel Janzen and Winnie Hallwachs, both ecologists at the University of Pennsylvania, who worked as researchers and technical advisers at Área de Conservación Guanacaste (ACG, Guanacaste Conservation Area) in Costa Rica for many years.
In 1997, Janzen and Hallwachs presented Del Oro, an orange juice manufacturer, with an innovative idea: If Del Oro would donate part of its land to the Área de Conservación Guanacaste, the juice company would deposit its orange peel waste for biodegradation, at no cost, on empty land within the park.
A deal was struck and in the first year some 12,000 metric tons of orange pulp and peels were dumped on a piece of waste land. Because of legal complications (a rival company sued Del Oro for “defiling a national park”), the plot now covered with mountains of orange peels and pulp lay largely forgotten until a team led by Princeton University researchers went back and inspected the area 16 years later.
“It was so completely overgrown with trees and vines that I couldn’t even see the 7-foot-long sign with bright yellow lettering marking the site that was only a few feet from the road,” Treuer said. “I knew we needed to come up with some really robust metrics to quantify exactly what was happening and to back up this eye-test, which was showing up at this place and realizing visually how stunning the difference was between fertilized and unfertilized areas.”
“The site was more impressive in person than I could’ve imagined,” Choi, a ecology and evolutionary professor at Princeton said. “While I would walk over exposed rock and dead grass in the nearby fields, I’d have to climb through undergrowth and cut paths through walls of vines in the orange peel site itself.”
There was 176 percent increase in above-ground biomass within the 3-hectare area studied, but in the overgrowth that had established itself in the interim, the original sign post to mark the area had completely disappeared.
Treuer and a team of researchers studied the site and compared it to other areas where the orange peels weren’t dumped. What they found was that the site fertilized by the orange peel was far better in every aspect. There was more tree biomass, richer soil, greater forest tree canopy closure and greater tree-species richness.
“Plenty of environmental problems are produced by companies, which, to be fair, are simply producing the things people need or want,” said study co-author David Wilcove, a professor of ecology and evolutionary biology at the Princeton Environmental Institute. “But an awful lot of those problems can be alleviated if the private sector and the environmental community work together. I’m confident we’ll find many more opportunities to use the ‘leftovers’ from industrial food production to bring back tropical forests. That’s recycling at its best.”
Story via Princeton University.