In Rwanda, scientists are working to protect and preserve endangered plant species found in hot springs.
This follows the rediscovery of a large population of Nymphaea thermarum, also known as the Rwandan miniature waterlily in 2023, a species believed to have been extinct in the wild since 2008.
This plant is found near a single hot spring known as Amashuza in Kinyarwanda. Previously, Nymphaea thermarum was known only from a single site in the Western Province of Rwanda. This water lily species, endemic to Rwanda, meaning it is the only place in the world it can be found. , thrives in damp mud formed by the overflow of a freshwater hot spring in southwest Rwanda.
Pascal Sibomana, a conservation scientist from the Centre of Excellence for Biodiversity and Natural Resources Management at the University of Rwanda, is one of the authors of a paper titled “Celebrating an “Extinct in the Wild” Waterlily Rescue in Rwanda,” published in the International Waterlily and Water Gardening Society journal.
Sibomana noted that the plant was thought to have become extinct in the wild when local farmers began using the spring for agriculture.
Sibomana also serves as an Associate Herbarium Collections Manager at the National Herbarium of Rwanda and has been documenting plant diversity within Nyungwe National Park and other protected areas in recent years. Other co-authors of the research include Michael B. Thomas and Bonny Dumbo Bosilana.
Dr. Michael Thomas, with over 25 years of professional experience in museum curation and conservation, is currently the Curator of the National Herbarium of Rwanda at the University of Rwanda. Bonny Dumbo Bosilana is a botanist who has consulted on numerous botanical projects throughout Central and East Africa.
“We need additional support through increased funding to develop infrastructure and research capacity. Nymphaea thermarum is just one of more than 50 endangered or threatened plant species we plan to target in the future,” the authors said.
Sibomana emphasised that Nymphaea thermarum, often celebrated as the smallest water lily in the world, plays a crucial role in its unique ecological niche and holds cultural significance for local communities.
Locally known as “Imposha,” the plant is also used as herbal medicine. The species was believed to be extinct in the wild since 2008, but a large population was rediscovered in 2023. Previously, the only known examples of this plant were cultivated in botanical gardens around the world.
After the rediscovery, the scientists are passionate about conserving it. “This represents a significant achievement in biodiversity conservation,” said Sibomana.
“We also noted its medicinal uses and occasional collection as livestock feed.”
Protecting its threatened Habitat
The water lily’s wetland environment is currently undergoing rapid transformation as farmers convert it to agriculture, growing cash crops like tomatoes, cassava, beetroot, amaranth, pineapple, colocasia, and various tree crops such as mango, avocado, papaya, macadamia, and oil palm.
Besides being endemic to Rwanda losing this plant species will mark the great loss of biodiversity, he said.
“We are working to engage stakeholders as conservation stewards to promote site protection measures and restoration efforts for Nymphaea thermarum and its unique habitat,” the conservation scientists said. They also highlighted that an industrial mining project poses significant threats to the species.
Recovery plan and future conservation efforts
The original discovery of the plant dates back to 1987, when a foreign scientist encountered it during plant research on the vegetation of the Albertine Rift in Rwanda. Now, scientists are developing the first species recovery plan for an endangered plant species in Rwanda.
“Lessons learned from collaborators at Harvard University’s Arnold Arboretum are guiding large-scale propagation techniques. Although Nymphaea thermarum is still listed as Extinct in the Wild on the IUCN Red List, a reassessment will update its status to Critically Endangered (CE).
Recent surveys have documented a much wider distribution than previously known,” the scientists stated in the journal.
The team has collected seeds and initiated a propagation and cultivation program. “The propagated Nymphaea thermarum seeds successfully germinated, and we currently have hundreds of ex situ seedlings since September 2023. This success provides a foundation for establishing a cultivation center for future reintroductions of the species,” cites the authors in the journal article.
Sibomana noted that they are now moving forward with a Master’s thesis research at the University of Rwanda in collaboration with the Royal Rotterdam Zoological and Botanical Gardens, as well as a student intern from Erasmus University Rotterdam.
“This collaboration will include a comprehensive study of its reproductive biology, physiological ecology, uses, and ecology,” he added.
Sibomana will be providing more research data pertaining to the up to date status of this endangered species in the upcoming 60th international annual meeting of the Association for Tropical Biodiversity and Conservation conference in Kigali slated for July 14-18, 2024
