Phyllanthus subcarnosus is a tree species from Cuba and Hispaniola that has been reported growing in mangroves, serpentine areas and calcareous regions. In the past, this tree has been collected in at least 20 localities in Cuba according to herbaria records. However, recent studies have pointed out that the species have been poorly collected over the past 20 years. This could be related to the low number of individuals of Phyllanthus subcarnosus observed during different prospections across Cuba, which is why it was considered a threatened species in a preliminary assessment. Nevertheless, the population size and structure are still unknown.
To assess the conservation status of the several subpopulations of the species and identify key threats in each locality, a two year conservation project started in 2017 with the support of Planta!’s Capacity Building Program.
During the field trips conducted by our team from October 2017 to February 2019, we have been able to identify four subpopulations so far, all of them in eastern Cuba. Trees of Phyllanthus subcarnosus are growing at Las Cejitas and La Abundancia in the province of Holguín, as well as in Mucaral and Monte Cristi, both in Guantánamo.
They could not been found at El Morrillo, Cascada de Cortinas Blancas, Río Piedra and Las Peladas. Although this last site has only been explored partially and there are still chances of finding the species here.
A total of 279 individuals of Phyllanthus subcarnosus have been monitored. The biggest subpopulation was found at La Abundancia, and the localities of Mucaral and Las Cejitas have been added to the distribution of the species in Cuba.
On the other hand, the main threats have been identified at each locality so they can be taken into consideration in future recovery plans. Among these are deforestation, agricultural development and invasive exotic species. The localities of El Morrillo and Río Piedra were very anthropized.
During the surveys of Las Peladas and El Morrillo, the team found Cynometra cubensis subsp. cubensis, a Critically Endangered endemic tree. Moreover, a subpopulation of Phyllanthus chamaechristoides ssp. chamaechristoides was located at Río Piedra. This species does not have enough data to assess its conservation status, so this could be the beginning.
The collaboration of technicians of the protected areas in La Abundancia, Mucaral, Monte Cristi and Las Peladas was vital for this project.
There are still several localities to monitor for new individuals of Phyllanthus subcarnosus, especially in western and central Cuba where the species has not been relocated yet. Additionally, some of the eastern localities with subpopulations have only been explored partially, so there might be more trees of Phyllanthus subcarnosus awaiting.