Recent genetic studies on the Dutch Caribbean native palm species, specifically Sabal antillensis in Curaçao and Sabal lougheediana in Bonaire, have provided crucial insights that confirms these two species are endemic for their respective islands. These palms, only described in the last decade, showcase not just the rich biodiversity of the Dutch Caribbean but also the possibilities for recovery! 

Sabal antillensis Curacao Seru Bientu Photo credit: Andre van Proosdij

Bonaire’s Sabal lougheediana is extremely threatened, with only an estimated 23 mature adults still in the wild.  Additionally, these palms are facing a population crisis, mostly due to continuous grazing by feral livestock (goats and donkeys), which keeps new seedlings from being established. In contrast, Curaçao’s Sabal antillensis is thriving under effective conservation strategies.  New research conducted as a collaborative effort between the Montgomery Botanical Center (Florida, USA), BonBèrdè, CARMABI, Wageningen University & Research and Cornell University employed genomic data to prove that both palms are indeed distinct species.  Results confirmed their genetic uniqueness, helping to answer two questions: are these two populations indeed different species? And are ex situ conservation efforts adequately representing the genomic diversity of each species? 

Genetic Issues  

An interesting result of this study was documenting a severe genetic bottleneck in Sabal lougheediana, characterized by low genetic diversity and high inbreeding levels. This is a concern as genetic diversity is crucial for species resilience against environmental changes and diseases. Conversely, Sabal antillensis shows slightly better genetic health but still needs strategic conservation to maintain and potentially improve its genetic diversity. 

Conservation Efforts 

In response to the urgent conservation needs, initiatives like the construction of a temporary exclusion fence, to protect at least part of the Sabal population on Bonaire have been implemented. This has led to immediate benefits, including a noticeable increase in seedling recruitment of plants inside the fenced area. By removing herbivorous pressure of goats and donkeys, these palms are able to reproduce and potentially increase genetic diversity over time. The implementation of the Bonaire Sabal Palm Park, a project aimed at the complete protection of the S. lougheediana on Bonaire has been submitted to the island government in 2020. Although funding for this project has been secured in 2023, the project is still awaiting its final approval. 

Furthermore, this study’s findings underscore the importance of ex situ conservation efforts, which involve preserving plants outside their natural habitats. These efforts have seen sufficient success, as the genetic makeup of the palms preserved ex situ closely mirrors those in the wild, suggesting that these conservation measures can help maintain genetic diversity should in-situ conditions worsen.

Sabal antillensis Curacao Seru Bientu Photo credit: Andre van Proosdij

Looking Forward 

This research is vital for the Dutch Caribbean, emphasizing the need for continued and enhanced conservation strategies. Protecting these endemic palm species is not just about preserving the current biodiversity but ensuring these unique genetic lineages endure for future generations. By integrating advanced genomic tools with traditional conservation methods, there is hope that these charismatic palms will thrive once again in their natural habitats. 

DCNA   

The Dutch Caribbean Nature Alliance (DCNA) supports (science) communication and outreach in the Dutch Caribbean region by making nature related (scientific) information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and through the press. This article contains the results from several (scientific) projects but the projects themselves are not DCNA projects. No rights can be derived from the content. DCNA is not liable for the content and the in(direct) impacts resulting from publishing this article. 

Bonaire Sabal lougheediana. Photo credit: Patrick Griffith

Curacao Sabal. Photo credit: Patrick Griffith

You can read the full article by visiting: https://link.springer.com/article/10.1007/s10592-024-01618-6