New mangrove species from Timor-Leste in Gardens by the Bay

DILI, Timor Leste – When Bay East Garden at Gardens by the Bay opens in 2027, around a tenth of the estimated 100 mangrove plants

could come from Timor-Leste and be planted in their new home by members of the public.

The plants from Timor-Leste include the smooth-fruited yellow mangrove (Ceriops australis), a mangrove species that can grow up to 10m tall and is not currently found in Singapore.

Handpicked propagules of this species, collected on Oct 18 from an area called Hera on Timor-Leste’s northern coast, about 12km from its capital Dili, were transported to Singapore on Oct 19 by a team from Gardens by the Bay.

In Gardens by the Bay’s own back-of-house nursery, horticulturists will propagate the propagules alongside other mangrove species that have been gathered for Bay East Garden from Pasir Ris Park since July.

Having plants from Timor-Leste in Bay East Garden was made possible by a memorandum of understanding (MOU) between Gardens by the Bay and the Timorese Ministry of Agriculture, Livestock, Fisheries and Forestry that was inked on Oct 17 in Dili.

The three-year agreement covers areas such as plant exchange, training and technical exchanges, and public education activities that promote appreciation and conservation of biodiversity.

Gardens by the Bay will also provide technical support for the planning, design, development and management of the Botanical Garden Francisco Xavier do Amaral, which was launched in 2016 but has yet to take off.

Timor-Leste has a land area of about 14,800 sq km, and Agriculture, Livestock, Fisheries and Forestry Minister Marcos da Cruz said after the MOU signing that while about 60 per cent of this is categorised as forested areas, it is lacking in dense forest cover.

Mr Adelino Rojario, chief of Timor-Leste’s Department of Reforestation, said later during a media tour of a government nursery that the country loses about 1.7 per cent – or more than 14,000ha – of its forest cover to deforestation per year due to factors such as illegal logging, forest fires, settlement construction, animal grazing, and slash-and-burn farming.

Gardens by the Bay is contributing to the country’s reforestation efforts by providing seeds that will be propagated in a government nursery and subsequently planted in the country at various sites, either directly by the government or by community groups.

For instance, during a plant-sourcing trip in August, Gardens by the Bay staff took with them seeds of a yellow-leaved variant of the Dendrolobium umbellatum that was first discovered in Vanuatu.

These seeds were planted on Sept 12, and had sprouted by the time Gardens by the Bay staff made a return visit to the nursery on Oct 17.

Mr Adelino said the plan is to distribute the Dendrolobium umbellatum plants for urban planting in December, coinciding with the start of the wet season in Timor-Leste that lasts till around May. The country’s climate is otherwise dry for most of the year.

During the October visit, Gardens by the Bay gifted the government nursery over 500 additional seeds, including more of the Dendrolobium umbellatum variant and three other species that are native to Timor-Leste, such as the Acacia oraria, which typically grows near the beach and is very salt-tolerant.

Mr Anton van der Schans, Gardens by the Bay’s principal horticulturist, said the species were selected based on several criteria, such as their presence in Timor-Leste, their ability to grow quickly, and their contribution to soil enrichment. He said that given the country’s reliance on agriculture, bringing in species that are already native to the country is prudent as this ensures that the new plants do not become a threat to existing native vegetation or crops.

Even though the species already exist in the country, seeds from elsewhere can help to expand the gene pool of the species, making them more resilient in the long term, he said.

Mr Adelino acknowledged that reforestation efforts have struggled to keep pace with deforestation in Timor-Leste. He said that at the country’s 13 government-linked nurseries, the goal is to produce one million seedlings per year for reforestation, which he estimates can cover 900ha of land, shy of the average deforestation rate of 14,000ha per year.

He said meeting targets has been an uphill task due to a lack of budget. Between 2023 and 2025, the 13 nurseries produced a combined 800,000 seedlings.

The Timor-Leste government’s reforestation efforts are complemented by the work of non-governmental organisations such as Konservasaun Flora no Fauna (Flora and Fauna Conservation in Tetum, the official language of Timor-Leste), which was established in 2014 and operates a mangrove study centre where locals can learn about the mangrove ecosystem.

The centre covers an area of about 50ha, and the organisation continues to help reforest coastal areas, such as by producing 30,000 to 40,000 mangrove seedlings per year for coastal reforestation.

It was at the study centre and a reforestation site that Mr van der Schans and his colleagues collected propagules of the smooth-fruited yellow mangrove and seeds of the Pemphis acidula, which is critically endangered in Singapore, with only a few specimens left on some offshore islands.

The plant is commonly called the small-leaved mangrove, but is in fact a mangrove associate – species that grow in or near mangrove ecosystems – and not a true mangrove species as it lacks specific adaptations that allow it to live in saline, waterlogged conditions.

True mangroves have one or more of the following adaptions: the ability to either exclude salt during water uptake or excrete it through their leaves, root systems that adapted to partially or fully submerged conditions, and seedlings that germinate while still on the mother plant.

Mr van der Schans said that sourcing mangrove plants from countries such as Timor-Leste is beneficial, as it allows the gardens to showcase species currently not found in Singapore. It also provides an opportunity to tap the expertise and experience of local horticulturists who have greater experience growing and restoring mangrove habitats.

He added that mangrove species are generally not available in commercial nurseries.

Gardens by the Bay deputy director of gardens operations Lai Liangfa said his organisation also hopes to integrate elements of how Timorese groups involve the community in mangrove restoration works into Singapore’s set-up and programmes for the upcoming wetland habitat.

For instance, he said, Gardens by the Bay intends to involve its citizen horticulturists – volunteers who have been given basic horticulture training – in monitoring and maintaining the mangrove plants for Bay East Garden.

This will happen at an on-site nursery in the garden to be set up towards the end of 2026. Mr Lai added that Gardens by the Bay also plans to have about 200 members of the public help plant the 100 mangrove plants and other mangrove associates in their permanent locations some time in 2027.

The wetland habitat at Bay East Garden will be Gardens by the Bay’s second such habitat after Kingfisher Wetlands,

and has more than 200 species of plants within its approximately 15,000 sq m area.

Gardens by the Bay chief operations officer Ong Kian Ann, who represented the gardens in signing the MOU, said such habitats are precious in Singapore given the country’s limited land, and require careful and deliberate planning.

“They may not be vast, but they are nonetheless important, as they bring city dwellers closer to nature and further contribute to Singapore’s vision of being a city in nature,” he said.