At higher altitudes, the montane forests take over, which host the third-highest number of documented endemic species. Though bereft of its natural vegetation, the central high plateau still retains islands of high diversity, says Pete Lowry, director of MBG’s Madagascar program.

The western flank of the island sports dry forests dotted by majestic boababs, a ubiquitous Malagasy motif. The harsh dry clime is not suitable for all life, but these stout giants flourish by storing water in their bulbous trunks. They are bearers of precious water and innumerable tales.  The Alley of the Baobabs and Baobab Amoureux in the west, the 1,600-year-old Grandmother’s Baobab in Tsimanampetsotse National Park in the south, and Mahajanga’s gigantic baobab in the northwest are landmarks on Madagascar’s landscape, must-sees on a tourist’s itinerary.

Of the nine baobab species on Earth, six are found only in Madagascar. Three of those are currently endangered, none more so than Adansonia perrieri, of which fewer than 250 mature trees remain today. Its cousin,  A. grandidieri, as its name suggests, counts among its ranks some of the grandest baobabs.  It is also faltering in the face of human-made threats. Lonely giants remain scattered around the famous Alley of Baobabs that cuts through a landscape ravaged by fire.

These trees are built to last; they are no stranger to fire, but even they cannot survive repeated burning. New seedlings also perish in fires because they lack the thick, protective bark of older trees. Their only shield is the vegetation around the parent tree. Isolated in a singed terrain, they are unable to regenerate.

The Boabab Amoureux. Image by Rhett A. Butler/ Mongabay.

Like baobabs, Sapotaceae trees, too, are difficult to replace.

Madagascar’s protected area network has expanded rapidly in the past decade, and today spans 7 million hectares (17 million acres). Yet 307 endemic tree species like L. ambondrombeensis lie outside this safety net. “Before establishing a protected area, we must know what we are protecting, and that is why these assessments are important,” said David Rabehevitra, a botanist at the Kew Madagascar Conservation Centre. “It helps in prioritizing conservation.”

Until 2017, only about 12% of the island’s tree species had been assessed. More species joined Madagascar’s ever-growing catalog of trees between the time the research took place and the report’s publication this year. Samples collected over many decades are still waiting to be disentangled, new species waiting to be described.

“We find new species every year. Even for species that have been discovered, we have a lot of work to do in gathering data,” Rabehevitra said. “It requires money and knowledge.”

These records allow researchers and conservationists to seek greater protection and funds not just for individual species but plots that could harbor other endemic species, known and unknown.

The approach has worked in some places. The Ankafobe protected area, co-managed by MBG, was set up, in part, after the discovery of the critically endangered Schizolaena tampoketsana in the tiny forest spread across 33 hectares (82 acres). Forest fires menace even this shard of forest. Community members have taken an active role in recent years to protect the forest with modest funding from MBG. They have put in place fire breaks and carry out patrols to prevent illegal logging.

In the case of L. ambondrombeensis, Laurent said they would like to see the existing protected area extended to the adjacent forest, where the tree is found. With biological riches hidden in every nook and cranny of Madagascar, deciding what to safeguard and what to leave out is devilishly difficult. “Population geneticists would say everything should be protected,” Laurent said. “but from the point of view of someone who has been in the field [and] seen the people trying to grow rice for their daily needs, we have to be reasonable in the trade-off between what is needed and what is possible.”

But protected area designation itself can only go so far if the dependence of people on forests and forestland is not reduced. With existing protected areas, deforestation pressure is often deflected to surrounding areas, Randriarisoa said. The L. ambondrombeensis trees standing at the edge of a protected forest also bear this brunt.

The COVID-19 pandemic has put Randriarisoa’s planned visit home and to the refuge of L. ambondrombeensis on hold. It is an unnerving wait as satellite imagery shows the green isles spangled across Madagascar steadily withering away.

Citations:

Randriarisoa, A., Naciri, Y., & Gautier, L. (2020). Labramia ambondrombeensis (Sapotaceae), a critically endangered new species from Madagascar. Candollea, 75(1), 83-87. doi:10.15553/c2020v751a8

Patrut, A., Von Reden, K. F., Danthu, P., Leong Pock-Tsy, J.-M., Patrut, R. T., & Lowy, D. A. (2015). Searching for the oldest baobab of Madagascar: Radiocarbon investigation of large Adansonia rubrostipa trees. PLOS ONE, 10(3). doi:10.1371/journal.pone.0121170

(Banner image of baobabs at sunset by Rhett A. Butler/Mongabay.)

Malavika Vyawahare is a staff writer for Mongabay. Find her on Twitter: @MalavikaVy

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