Left unchecked, the combined effects of deforestation and human-induced climate change could eliminate Madagascar’s entire eastern rainforest habitat by 2070, impacting thousands of plants, mammals, reptiles, and amphibians endemic to the island nation, finds new research from The Graduate Center at the City University of New York, CUNY.
Published in the current issue of the journal “Nature Climate Change,” the study also shows that protected areas will help to lessen the devastation while environmentalists work toward long-term solutions for ending runaway greenhouse gas emissions and the resulting climate change.
The study identifies areas of intact forest that could be prioritized for protection to enable resilience and survival of threatened species.
Madagascar, the world’s second largest island country after Australia, lies in the Indian Ocean, 250 miles (400 kilometers) off the coast of East Africa. As a result of the island’s long isolation from neighboring continents, Madagascar is inhabited by animals and plants found nowhere else on Earth.
It is a biodiversity hotspot where 80 to 90 percent of its animal and plant species are exclusive to the area, but the land has been devasted by decades of deforestation and overharvesting, destroying much of the land cover that provides habitat for unique animals, including endangered varieties of lemurs.
In particular, two species of ruffed lemurs are now critically endangered, and these animals play a central role in dispersing the seeds of plant species that provide food and shelter for other animals across the rainforest.
“Because of their essential role as seed dispersers and their sensitivity to habitat degradation, ruffed lemurs serve as a critical indicator of the health of Madagascar’s entire eastern rainforest,” said Dr. Andrea Baden, a professor of anthropology at The Graduate Center, CUNY and Hunter College and the study’s primary investigator.
Lemurs have been characterized as “Madagascar’s flagship mammal species” by Conservation International. In the absence of monkeys and other competitors, these primates have adapted to a wide range of habitats and diversified into numerous species.
As of 2012, there were officially 103 species and subspecies of lemur, 39 of which were described by zoologists between 2000 and 2008. They are almost all classified as rare, vulnerable, or endangered. At least 17 species of lemur have become extinct since humans arrived on Madagascar.
Dr. Baden and her team employed a case study of the two critically endangered ruffed lemurs using three decades of research throughout Madagascar to analyze threats to the country’s eastern tropical rainforest.
“When we projected the impact of deforestation and climate change, we found that deforestation alone and climate change alone could reduce ruffed lemur habitat by over 50 percent,” said Baden. “Even more alarming, these two factors together are projected to essentially decimate suitable rainforest habitat by the end of the century.”
The researchers’ data suggest that the speed and intensity of destruction to Madagascar’s eastern rainforest will be determined by whether the country institutes strict protections against deforestation or a relaxed set of policies.
Protecting forested areas that provide shelter to ruffed lemurs and serve as corridor links to their strongholds is particularly important to survival given their role as a keystone species that enables the survival of a large number of other animal and plant species in one of the world’s most biodiverse regions.
A number of other mammals, including the cat-like fossa, are endemic to Madagascar. Over 300 species of birds have been recorded on the island, of which over 60 percent are endemic. The island nation is inhabited by two-thirds of the world’s chameleon species, including the smallest known, and scientists have proposed that Madagascar may be the origin of all chameleons.
More than 80 percent of Madagascar’s 14,883 plant species are found nowhere else in the world, including five plant families. Many plant species native to the island are used as herbal remedies. The drugs vinblastine and vincristine are vinca alkaloids, used to treat Hodgkin’s disease, leukemia, and other cancers, were derived from the Madagascar periwinkle.
“The results from our study will be useful to nonprofit organizations, park management, and the broader conservation community,” Baden said. “Our results indicate potential conservation opportunities for ruffed lemurs and any of the rainforest-dwellers that rely on forest cover and connectivity. Protected areas are vital to species persistence.”
Nonprofit gorups are already at work protecting this unique and threatened area.
Conservation International has had conservation projects in eastern Madagascar since 1996. The nonprofit organization based in the United States is currently supporting the government of Madagascar in the development and implementation of “a conservation-conscious sustainable development strategy for the area.”
Conservation International has developed a pilot project in the Ankeniheny-Zahamena Corridor of eastern Madagascar that aims to generate carbon credits that can be sold to companies or other buyers looking to offset carbon emissions. Validated by an external auditor, the Rainforest Alliance, the project engages communities through conservation agreements that give these communities financial incentives to conserve their forests and monitor threats.
The World Wildlife Fund, WWF, has been active there for more than three decades, working with local communities to protect Madagascar’s unique environment.
For the 60th anniversary of Madagascar’s independence from France in 1960, 60 million young plants will be planted to green Madagascar.
In response to an invitation from the Ministry of the Environment and Sustainable Development, MEDD, some 20 environmental organizations and several university students are involved in this citizen mobilization.
WWF is fully in line with MEDD in the greening of Madagascar. “In all of our intervention landscapes, we are ready to help in the search for reforestation sites. We are also ready to help with the planting in 2020,” says Rina Andrianarivony from WWF.
“It is not only the business of MEDD, neither of WWF, nor of NGOs, it is the business of all Madagascans,” she declared. “Let’s reforest!”
Jaozandry Jean Jacques, director of Reforestation and Management of Landscapes and Forests within the MEDD, says, “We plan to officially open reforestation in Madagascar in January 2020.”