A farmer harvesting Prunus africana in Cameroon. CIFOR

We’ve seen it happen before with the trade of crocodiles, snakeskins and orchids — and now, scientists are calling for a shift from the wild harvest to the cultivation of Prunus africana bark.

Prized for its ability to treat swelling of the prostate, P. africana — widely known as the African Cherry — is internationally traded more than any other African medicinal plant species.

Yet for decades, wild harvests have been unsustainable and of little tangible benefit to local livelihoods, according to Terry Sunderland, a scientist at the Center for International Forestry Research (CIFOR).

“The fact is, this trade in wild bark is fundamentally unsustainable,” said Sunderland, co-author of a new study looking at the wild bark trade of P. africana.

“We’re trying to get the companies to recognize that and to insist on alternative sources of supply, particularly from cultivated sources.”

Bankable Bark

The harvest of P. africana, which is found in the montane forests of Africa, shifted from subsistence use to large-scale international trade at the start of the 1970s. These montane forests themselves are going to be greatly affected by future climate change scenarios, putting further pressure on the species.

Its bark is usually exported dried, chipped or powdered to Europe and the United States to treat benign prostate hyperplasia (BPH)- a swelling of the prostate gland that affects many middle-aged men around the world.

Over-the-counter retail value of the trade in P. africana herbal remedies was estimated at US$220 million per annum.

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Prunus africana- a reality check

But its trade has been far from sustainable. Growing concern with the state of wild stocks led to P. africana being listed in Appendix-II of the Convention on International Trade in Endangered Species (CITES) in 1995. In 2007, concerns about its unsustainable wild harvest led to an import ban by the European Union (EU).

The ban was lifted in 2011 due to pressure from pharmaceutical companies and the Cameroonian government. A quota system for the major producing regions was introduced in its place.

Now, with recent CITES export restrictions on P. africana exports from Burundi, Kenya and Madagascar, Cameroon has become the biggest global supplier by far, followed by Uganda and the Democratic Republic of Congo.

However, wild stocks are still vulnerable, according to the CIFOR research, and Cameroon’s Prunus africana Management Plan is not quite the sustainable model it’s made out to be.

“Much of the management plan that was created in 2007 and 2008 was based on incomplete data — both environmental and livelihood.”

This has led to some notable gaps between rhetoric and reality, according to the study.

For example, the idea that wild harvests are important to local livelihoods “just doesn’t cut it”, said Tony Cunningham, the lead author of the study.

Fieldwork by the study’s authors found the 48 active harvesters working in the Mount Cameroon National Park received less than $1 a day due to a net bark price of $0.33 per kg. However, the 2012 bark quota from Cameroon was worth $3.9 million at $6 per kg. The bulk of this went to a single company.

Furthermore, the study found that P. africana bark directly benefits only 0.0004 percent of the population around Mt. Cameroon.

There are similar gaps between rhetoric and reality when it comes to sustainability, the study found. The current norm of five-year rotation times after the first wild bark harvests has been found to be too short. What are needed are rotation times of at least seven to eight years.

And “correct” bark stripping — only two-quarter panels from a tree measuring more than 30 cm in diameter — has been found to critically damage trees in the longer term.

Compliancy through cultivation

Sunderland and his colleagues are calling for a “reality check” — and say what is required to sustainably supply the current and future market for P. africana bark is a move towards cultivation.

“There are very few environmental benefits and very few livelihood benefits from wild harvests,” Cunningham said. “If you switch it and harvest from cultivators, who have secure land and resource tenure and can contribute to carbon storage, then you will have a much better outcome for both the environment and for livelihoods.”

Shifting from wild harvests to cultivation won’t be easy, however. Research that shows the wild harvest of P. africana as unsustainable has been largely ignored for decades, according to Sunderland.

“It’s an easy species to hijack,” Sunderland said. “There is such a strong advocacy movement out there in terms of business. The industry itself wants wild harvests to continue because it means lower costs for them and maximum profits.”

Sunderland said the EU needs to be prepared to make some hard decisions.

“They could stop potentially unsustainable wild sources of Prunus from being imported into the EU if it came to it.”

He added that CITES could also control the global trade through quotas and proper inventories from source countries to producer countries.

Ultimately, however, developing a separate, traceable supply chain based on cultivated stocks is what is required to ensure sustainable harvest, the study concludes. What’s more, the species propagates readily and is relatively fast growing – perfect for mixed agroforestry systems.

“We need to start investing in the people that have farmed Prunus for 20 or 30 years and start buying material from them,” Sunderland said.

“And set up a traceability system that the government is willing and able to monitor. A traceability system that is CITES-compliant.”

“This is a timely reminder,” Cunningham added. “Virtually all commercially harvested bark products we are familiar with in large-scale global trade – whether cinnamon, cassia, quinine or wattle bark (for tanning leather) – are now sourced from cultivated stocks.

“Prunus africana is one of the only two exceptions that still come from the wild, along with Quillaja saponaria. It would be far better to shift supply chains to cultivated Prunus stocks to benefit small-scale farmers and the environment.”