The island’s unique plants are being preserved in the world’s biggest seed bank
|Madagascar and Sussex
In a 4x4 bumping and rattling along a dirt road in Madagascar, Nomentsoa Randriamamonjy explains a local idiom. A few generations ago, the phrase “when the eastern forest disappears” was Madagascar’s equivalent of “when pigs fly”. That forest once stretched the entire length of the island’s east coast, some 1,600km (see map).
Tree cover, 2000
Tree loss, 2001-24
Madagascar
Antananarivo
Antavolobe
Forest
Sources: Hansen;
UMD; Google; USGS; NASA
But slowly the phrase fell out of use. The loss of the eastern forest no longer seemed impossible—or even distant. The rainforest, and Madagascar’s many other wooded areas, are under threat from the usual suspects: climate change, wildfires, slash-and-burn agriculture and invasive species. Between 2001 and 2024 a quarter of the country’s native rainforest vanished. That matters. Madagascar became an island around 90m years ago, leaving its inhabitants evolutionarily isolated. Around 80% of the plant species found there today live nowhere else in the world.
That is where people like Mr Randriamamonjy come in. A botanist at Kew Madagascar—an outpost of the Royal Botanic Gardens, whose headquarters are at Kew in London—he has the painstaking, and sometimes dangerous, job of collecting seeds from threatened plants. His work is the first stage of a huge conservation endeavour. The tiny parcels of life that he collects in the field eventually make their way to the shelves of Kew’s Millennium Seed Bank (MSB) in Sussex, England, the world’s largest archive of wild plants. There, seeds are not just locked away in case of some future catastrophe. They are also used for research, restoration and to help secure the world’s food supplies.
The MSB, as its name suggests, celebrates its 25th anniversary on October 22nd. Its vast underground freezers store more than 2.5bn seeds from 40,000 species—around 10% of the world’s plants. Most are collected by partner organisations abroad (samples are also held in local repositories). Madagascar is the only country besides Britain where Kew has its own office, with around 60 staff.
Henintsoa Razanajatovo from Kew Madagascar records information about the location and population of a species from which seeds have been collected (top). Nomentsoa Randriamamonjy inspects a plant with a microscope in the Antavolbe forest (middle). A ripe fig fruit found in the Antavolbe forest (bottom).
When your correspondent joins Mr Randriamamonjy—before the coup of October 14th, in which the army said it had seized power in the country—he and his colleagues are bound for Antavolobe, a protected area of humid forest 100km east of Antananarivo, Madagascar’s capital. Plains lined with rice paddies soon give way to dense tree cover. At the forest’s entrance are local guides, whose knowledge of the terrain and flora are invaluable. Once inside the forest, the guides point out medicinal plants. Centella asiatica is a small herbaceous plant whose leaves have anti-inflammatory properties. The Madagascar periwinkle is a source of vinblastine, vincristine and vinorelbine, a trio of anti-cancer medicines.
Seed collecting is not for the faint-hearted. Some expeditions involve three- or four-day drives along potholed roads and dirt tracks. The remotest sites can be reached only by trudging through the forest for days on foot. Mr Randriamamonjy and his colleagues can spend several weeks subsisting on rice and the fish he is able to dazzle with his head torch and catch bare-handed.
Seeds to be cleaned and tested for germination, before being stored in the Malagasy seedbank, Silo National des Graines Forestieres (SNGF) in Antananarivo, and the Millennium Seed Bank, in Britain
On each mission the team has a list of ten or so target species. They prioritise those that are endemic, endangered and economically important. A successful trip generally ends with 15 different samples, though days can pass with no luck. Sometimes there are thrilling surprises. Recently, in one remote site, Mr Randriamamonjy and his colleagues rediscovered a species of aloe that was presumed extinct—it had last been seen in 1910. Since their most recent funding award in January 2024, the Kew Madagascar team has added 18 new tree species to their collection, one of which is entirely new to science.
Climate change makes their work harder. Seeds can be collected only when a plant’s fruit is ripe, and the rhythms of the past have become an unreliable predictor of when fruits will be ready today. Sometimes, the team travels for days only to find the berries they were looking for are already gone. One of the guides laments the Madagascar rosewood, a tree that once fruited here yearly, but has borne nothing in the past five. The Kew team are helped by locals with smartphones who record data on target plants nearby.
Finding ripe berries is just the beginning of the process. Before taking the seeds, the team counts the number of individual plants of the target species nearby. They only ever gather a fifth of the ripe fruit, leaving the rest for the lemurs and birds. In each collection they aim for about 1,000 seeds. They also record data on the population and location, gather leaves for DNA analysis and take cuttings for herbaria in Madagascar and Britain.
Any seeds and specimens that the team collects from the field are first taken to Antananarivo. Crinkled cuttings are mounted on a card, photographed for the database and filed in towering metal cabinets. Seeds are cleaned and dried, tested for germination—there is no point in storing lifeless kernels—and then split between the Silo National des Graines Forestières, Madagascar’s national seed bank, and Kew’s repository in distant Sussex.
A view inside the freezer at the SNGF in Antananarivo (top). Cabinets housing plant samples in the National Herbarium of Madagascar at the Tsimbazaza Botanical and Zoological Garden in Antananarivo (bottom).
Seed banks are often thought of as “doomsday” vaults, says Charlotte Lusty, head of seed collections at Kew. But in reality, they are more like libraries: samples are checked out of the MSB every week. Many of the seeds that are withdrawn from the bank are used for restoration. During Australia’s ‘black summer’ of 2019-20, for instance, wildfires nearly wiped out a rare pea species, Glycine latrobeana, found in mountains near Adelaide. Thankfully, seeds of the pea were held at the MSB. These were sent back to Australia, allowing the species to dodge extinction and be reintroduced to its natural habitat.
The seeds can also improve food security. Kew helped set up the Crop Wild Relatives project in 2011. This collected seeds from the wild cousins of staple crops with the eventual goal of crossing them with domesticated varieties to create plants that can better withstand climate change and disease. Kew trained collectors across 25 countries. By the end of 2021, when the project finished, 3,667 wild-relative samples were held at the MSB. Some of these were then sent out to international gene banks, which plant the seeds ready for crossing. Several improved varieties of durum wheat have already been commercially released, including Jabal, a drought-tolerant strain which takes traits from goatgrass, a wild wheat collected from the dry Syrian plateaus.
Researchers mount plant specimens on card for storage in the National Herbarium of Madagascar, Antananarivo.
Back in Antavolobe forest, Mr Randriamamonjy plucks a handful of orange spheres, the size of marbles, from a low branch. He slices one open to reveal a magenta interior flecked with tiny white seeds: a perfect fig. But there is a catch. This fig has “recalcitrant” seeds rather than “orthodox” ones. Recalcitrant seeds are those with a high water content and which are still metabolically active. That means they cannot survive drying or freezing, and cannot be banked. Still, the fruit will not go to waste. One of the guides saves a few to plant in a nursery, where seedlings are raised to restore degraded patches of forest.
Many of Mr Randriamamonjy’s seeds are already being put to work to help restore and maintain Madagascar’s biodiversity. Local charities and the Malagasy government often buy seeds from the national seed bank to use for restoration. Kew is also involved in replanting efforts. In Ankarafantsika National Park, a dry forest in the north of the country, the team has planted 30,000 seedlings across six hectares of degraded land.
The plant nursery at SNGF, in Antananarivo. (top) Seedings growing in the nursery. Some will be used for forest restoration (bottom).
Whether official co-operation will continue under military rule remains to be seen. Since 2001 around 215,000 hectares of the country’s forest have been lost each year. At this rate, all of Madagascar’s primary forests will be gone by 2100. The seed bank may one day serve as a final refuge for Madagascar’s plants, but its primary purpose is to ensure that never happens. The old saying assumed that the disappearance of the forest was unthinkable. Perhaps one day, thanks to these seeds, it will be unthinkable again.■
Photographs: Kevin Ramarohetra
Paddy fields line a valley between Anananarivo and Antavolobe forest
