The Critically Endangered Haitian endemic palm Attalea crassispatha (Arecaceae) and its living collections in Fairchild Tropical Botanic Garden: Perspectives from conservation surveys and DNA microsatellite (SSR) data

From Firenze University Press Journal: Journal of Plant Taxonomy and Geography (Webbia)

Brett Jestrow, Fairchild Tropical Botanic Garden, Coral Gables

Michael Hass, Fairchild Tropical Botanic Garden, Coral Gables

William Cinea, Jardin Botanique des Cayes, Bergeaud, Les Cayes

Alan R. Franck, Institute of Environment, Department of Biological Sciences, Kimberly Green Latin American and Caribbean Center, Cuban Research Institute, Florida International University

Joel C. Timyan, P. O. Box 121023, Melbourne

M. Patrick Griffith, Montgomery Botanical Center, Coral Gables

Javier Francisco-Ortega, Institute of Environment, Department of Biological Sciences, Kimberly Green Latin American and Caribbean Center, Cuban Research Institute, Florida International University

Almost 30 years ago the first-known work focus-ing on an ex situ conservation program for a Critically Endangered plant species endemic in Haiti was published by Timyan and Reep (1994). The study concerned one of the most threatened palms of the Caribbean Islands, Attalea crassispatha (Mart.) Burret, and it provided an account on the status of this species in the wild as well as a germplasm collection initiative that had two aims: (1) introducing the species in private gardens of Haiti and (2) developing ex situ conservation collection of living plants in botanic gardens and horticulture stations. The target species is restricted to southern Haiti (departments of Sud and Nippes at Peninsule de Tibu-ron) and it is the only Caribbean Island endemic in the Neotropical genus Attalea (~30 species; Henderson 2020). In 1994 only 25 plants (19 adults– including a senescent plant, and six juveniles) were found in eleven sites, but none of these localities had more than ten individuals (Figure 1A, Table 1). A more recent survey made by Timyan (2001) reported 18 seedlings, six juveniles, and 24 adults along the distribution range of the species. Based on the age of the original description, this suggests that this palm was more abundant in the late 17th century (Martius 1844: 110–112, as Maximiliana crassispatha Mart.), and even Charles Plumier (1646–1697) drew and published a plate and a description of this species (Plumier 1703: 2, Plate 1; Figure 2). This pre-Linnean French botanist and monk traveled twice to Haiti between 1689 and 1693 (Mottram 2002). Based on our own field observations and palm conservation work conducted in the Caribbean with other species, reasons for its decline are unsustainable harvest-ing of seeds for human consumption, introduced herbivores, and clearance of land for agriculture (Timyan and Reep 1994; Jestrow et al. 2018; Freitas et al. 2019).As part of this ex situ conservation program imple-mented in the late 1980s and early 1990s, seeds were sent to 16 botanic gardens or agricultural research stations in South America, Central America, Germany, Australia, and Asia (Timyan and Reep 1994).

According to Timyan and Reep (1994), two main shipments of seeds were dis-tributed. The first happened in 1989, and was the most extensive one, having Fairchild Tropical Botanic Garden (FTBG), Miami, Florida as the hub for germplasm distribution. It involved sending seeds that were collected from five different mother plants from four places (localities A, D, G, and J). Germplasm was sent to 13 botanic gardens and five other sites (Timyan and Reep 1994: Table 4). These seeds were also sent to Tropical Research and Education Center (TREC) and resulted in the plants currently cultivated in this research station of the University of Florida. The second consignment (har-vested in 1991) was more limited in number of germ-plasm samples; and seeds were shipped only to botanic gardens in Australia, St. Vincent (Lesser Antilles), and Guyana (Timyan and Reep 1994), with samples received by FTBG as well. This second batch had the progeny of nine different mother plants from nine different places (localities A–H and J, Figure 1A); however, FTBG suc-cessfully cultivated plants from only A, B, and D (Fond-des-Nègres region, in the northeastern area of the species distribution range).

It is worth mentioning that Timyan and Reep (1994) found only six plants in these three localities. Regarding material distributed in Haiti, a total of 117 seedlings were sent to private gardens and non-government organizations between 1990 and 1991. Fairchild Tropical Botanic Garden received a third shipment of seeds in 2001 (also from Fond-des-Nègres region), as the ex situ conservation project continued.The contribution here presented has two main objectives. The first one concerned revisiting the localities reported by Timyan and Reep (1994) to determine if there have been any changes regarding the Attalea crassispatha population demographics of these sites. This is particularly relevant in Haiti, a country that it is considered to have one of the highest deforestation rates of the Americas, and has experienced major socio-political turmoils in the last 50 years. In addition, this Caribbean country has been affected by major environmental disasters such as the catastrophic 2010 and 2021 earth-quakes and six devastating hurricanes (Georges in 1998, Dennis in 2005, Gustav in 2008, To m a s in 2010, Matthewin 2016, and Laura in 2020) that hit the area where this palm occurs. We wanted to assess the conservation sta-tus of one of the most threatened Caribbean palms since the last field conservation-oriented actions were taken in the 1990s by Timyan and Reep (1994) and Timyan (2001). The results of this first objective could provide some insights regarding long-term conservation goals performed in situations in which external detrimental conditions can evolve.

The second objective was to investigate the current ex situ genetic conservation status of the collected material at FTBG. Our results are complementary to those recently published in an exhaustive and comprehensive genetic conservation study of populations of this species in (1) ex situ living collections of Montgomery Botanical Center, FTBG, Singapore Botanic Garden, USDA Chap-man Field Station at Miami, and the Tropical Research and Education Center (TREC) of the University of Florida at Homestead, Florida, and (2) eight wild sites of Haiti. This work was published by Diaz-Martin et al. (2023) based on 6093 single nucleotide polymorphisms (SNPs) and to identify optimal breeding pairs for future ex situ conservation actions.In many instances ex situ conservation goals con-cern sample strategies in small populations in order to maximize the amount of genetic diversity that can be preserved in living individual germplasm banks. This is relevant in the tropics where the vast majority of species have recalcitrant seeds and cannot be massively stored in seed banks (Normah et al. 2019). Therefore, living plant germplasm banks with a very limited number of individuals is in many cases the only feasible alterna-tive to ex situ conservation. The use of highly variable co-dominant molecular markers known as SSR micro-satellites provide cost-effective quick tools to determine levels of genetic variation both in the natural popula-tions and in those that are ex situ conserved (Griffith et al. 2017, 2020). These co-dominant markers were not so commonly available in 1994 when conservation activities targeting Attalea crassispatha were implemented. The strategy for ex-situ conservation established by Timyan and Reep (1994) was based on seeds collected from a limited number of mother plants across the distribution range of the species. Because in its natural environment this species has very few individuals it was assumed that this sampling strategy would not result in a major genet-ic bottleneck between the original populations and those established in the ex situ collections. Therefore, our genetic conservation goal at FTBG was to use SSRs to investigate the success of establishing genetic conserva-tion in an ex situ living collection of a Critically Endan-gered species when the available germplasm comes from a very reduced number of individuals.

DOI: https://doi.org/10.36253/jopt-14606

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