Chocolate and the Emerging Science Protecting Rainforests

The Congo Basin, the second-largest tropical rainforest in the world, teams with abundant wildlife and native plants. Given its enormous carbon storage capacity, the 500-million-acre region spanning six African countries is vital for regulating global climate. It’s also home to more than 75 million people. 

Biologist Luke Powell, A03, is a frontrunner in developing innovative approaches that balance conservation of such threatened ecosystems with support for the livelihoods of local people who are reliant on rainforests for commodity crops, such as coffee and cocoa. Based at in Porto, Portugal, he is director of the Gulf of Guinea Research Program at CIBIO/Biopolis, the Centre for Research in Biodiversity and Genetic Resources.

As a scientist who now leads research initiatives, he aims to ensure that the extraordinary Congo Basin, home of the largest remaining undisturbed stands of tropical rainforest on the planet, is protected from the devastation of deforestation, even as intense land pressures mount. 

The region spans Cameroon, Central African Republic, Democratic Republic of the Congo, Republic of the Congo, Equatorial Guinea, and Gabon and is home to 10,000 species of tropical plants, endangered wildlife—including forest elephants, chimpanzees, bonobos, and lowland and mountain gorillas—plus hundreds of other species of mammals and thousands of bird species. It faces significant pressures, in part because Africa’s human population is projected to quadruple by 2100.

“The Congo Basin represents a conservation frontier,” says Powell, who is also co-founder and director of the Biodiversity Initiative, an international research and conservation co-op. “But if we want to protect it, we need to bring resources and people together to advance biodiversity research, and now.” 

Pivot Points

Powell grew up on Long Island with a deep love of the outdoors. At Tufts, he majored in biology and environmental studies. A pivotal experience was a Tufts field trip led by Department of Biology Professor George Elmore, to Hummingbird Cay in the Bahamas. 

“That was where I realized I wanted to immerse myself in tropical research,” Powell recalls. “I owe many thanks to Professor Ellmore as well as to Michael Reed and Benjamin Dane for shaping me as a young biologist.” 

After graduation, Powell took “as many field jobs as possible,” including, in 2005, as a volunteer monitoring parrots at clay licks in southeast Peru—the work at Los Amigos Research station (CICRA) later helped produce his first scientific publication. Returning to New England, he earned a master’s degree at the University of Maine, where he studied the rusty blackbird, whose population is rapidly declining, “but my eye was always toward finding a way to get back to the tropics,” he says. “Tropical rainforests may account for seven percent of the Earth’s land surface but they represent 50 percent of the planet’s biodiversity. To me, they were where the action was.” 

Through a Ph.D. at the University of Louisiana, he immersed himself in the central Amazon and developed his fascination for birds considered “ecosystem sentinels.” These insectivores thrive in the forest’s thick understory and are highly sensitive to habitat disruption. “They are among the first to disappear when the forest is degraded and among the last to return, if the forest in fact recovers,” he says. “That makes them really great indicators of the health of the tropical rainforest.”

Capacity Building for Conservation

Powell followed graduate school with postdoctoral research on interspecies competition in birds at the Smithsonian Migratory Bird Center before, as a Marie Curie Fellow with the University of Glasgow, he turned his attention to sustainable cacao agroforestry.

Cacao farms, which respond to the world’s ever-growing appetite for chocolate, can thrive under a lush canopy of rainforest trees, the same shade trees that are habitats for African birds and bats. “If managed appropriately,” says Powell, “I thought the cocoa farms could likely support a level of biodiversity comparable to that of a primary rainforest. It was an area of research ripe for inquiry.”

At the same time, he and other scientists were concerned about the rapid loss of rainforests around the world. According to Global Forest Watch, humans have wiped out nearly half of the world’s original forest cover and the destruction continues; tropical forestland equivalent to the size of Bangladesh—more than 36 million acres—is lost every year . 

Founding Biodiversity Initiative in 2013, says Powell, was one way to bring people together to curb that devastation by training local biologists and conservationists in Sub-Saharan Africa. “While the Brazilians had really built up their capacity to be the stewards for their own natural world," he says, "no such infrastructure existed in much of Africa—especially in the Congo.” 

Their biggest accomplishment to date, says Powell, is developing a national park in Equatorial Guinea. They have also held workshops for nearly 1,000 farmers in Cameroon to help them improve income and sustain biodiverse farms. Also fulfilling is the realized dream of opening up opportunities for aspiring biologists. Cameroonian Tabe Tiku Regine Claire, he says, “went on to earn her master’s in Glasgow and is now she’s a Ph.D. student in Vienna. Someday, before long, she’ll land a professorship in Cameroon and mentor her own students.”

The Deforestation Threat

Up to 75% of the world’s chocolate comes from Ivory Coast, Ghana, Cameroon, and Nigeria, mostly from small, family-owned farms tucked in and around natural rainforest ecosystems. Compared to coffee and palm oil plantations, where other plants are often cleared out, says Powell, cacao can be less invasive; cocoa trees can grow under the shade canopy of the rainforest, retaining more than 95% of native bird species. 

But the key driver of deforestation of tropical rainforests, in Africa as elsewhere, is pressure to clear land to grow more crops. Larger harvests of cocoa are possible in clearcut areas, but planting what is known as “full-sun” cocoa in Ivory Coast and Ghana is creating an “ecosystem collapse in these countries,” says Powell. And given that most consumers of chocolate are in Europe and the United States, “it is our responsibility to mitigate the issue,” he says, “it’s a question of ethics.” 

With environmental consciousness increasingly on the minds of consumers, Powell said it’s possible to continue to enjoy chocolate, just scrutinize the labels and so-called sustainability assertions. What to look for: Truly sustainable chocolate, he said, is shade grown and “bean to bar,” or 100% traceable from the grower to the finished chocolate bar, he said, citing two companies— Beyond Good and Alter Eco—that are hewing to business models focused on fair trade and environmental sustainability.

The Ecology of Cocoa 

One of Powell’s first studies yielded new insights about cocoa crops as bird habitats. He and a fellow Ph.D. student asked: Are cocoa trees good places for forest-specialist birds, or birds that thrive in primary rain forests? At more than 200 sites across Cameroon and Equatorial Guinea, the researchers looked at full-sun cocoa farms, shade cocoa farms, and primary rainforests. 

While the cocoa farms supported some bird species, the specialist species were missing; the primary rainforest supported about eight times the number of forest specialist and ant-following birds found on cocoa farms. Such findings, says Powell, made a persuasive case: “You absolutely need primary rainforests to preserve ecological integrity.”

In another study, the research team used a technique called DNA metabarcoding in Cameroon, the team determined that 12 bird and six bat species were eating a primary cocoa pest, called brown capsids, that is responsible for millions of dollars in damage. By placing netting over selected trees, the researchers further showed that cocoa trees that insectivorous birds or bats could not visit had more pests and produced 27% fewer pods.

The upshot? The findings show that “African farmers benefit through inexpensive, sustainable management of cocoa, and rainforest animals benefit through the planting of trees that mimic their natural habitat,” says Powell. The research helped bring about a shift in attitude among farmers when they understood how beneficial native birds and bats are as pollinators for their crops. “As the demand for cocoa increases, we will continue to seek a win-win framework in which both biodiversity and African farmers benefit through sustainable and profitable management of cocoa.”

A Larger Vision

Looking ahead, Powell is hopeful that researchers, local communities and conservationists can ensure rainforest survival. One of the central goals of his work is a fledgling project with The Rainforest Trust and INDEFOR-AP [Equatorial Guinea’s Protected Areas Program] to create a national park in Equatorial Guinea that would encompass 1000 square kilometers, roughly twice the size of New York City. 

The project would support the United Nation’s global conservation framework (known as 30x30, it aims to protect 30 percent of marine and land area by 2030) and would leverage survey data to help design reserves to maximize the conservation of the Gulf of Guinea’s biodiversity—including endangered forest elephants, chimpanzees and gorillas.

“This is quite exciting not just because it protects our study sites, but also because it’s a wonderful opportunity for Equatorial heritage,” he says. “The idea is that if you understand the biodiversity that is there, then you can make the best possible informed decisions about how to protect the remaining slices of rainforests. That's our dream, and it might well end up being my life's work."

Luke Powell shares more about his research in a video of his 2021 Hoch Cunningham Environmental Lecture.