The Ecology of a Rare Species, Solanum conocarpum, in St. John, US Virgin Islands

Cecilia L. Rogers; Heather P. Griscom

The Ecology of a Rare Species, Solanum conocarpum, in St. John, US Virgin Islands

Cecilia L. Rogers¹^,* and Heather P. Griscom¹

¹James Madison University, Harrisonburg, VA 22807, USA.*Corresponding author.

Caribbean Naturalist, No. 69 (2019)

Abstract
Approximately two thirds of the island of St. John in the US Virgin Islands is national park territory. However, the land has been threatened with tourism and development, greatly impacting island biodiversity. One species that may become extinct due to this degradation is Solanum conocarpum (Marron Bacoba). It is a rare shrub, endemic to the dry tropical forests of St. John. This species is one of few native endemic plants on this island. Little is known about the ecology and reproduction of S. conocarpum. Recent observations have indicated that the greatest threat may be lack of seedling recruitment, possibly due to acute disturbances. This study investigated the ecology of S. conocarpum in order to identify optimal areas for establishing populations. We recorded a total of 202 individuals at 4 sites and for each also noted plant growth and presence/absence of flowers and fruit. Indicators of plant health differed significantly between the 4 populations. The population closest to the shoreline (Nanny Point) had the greatest number of individuals (N = 161) and largest size (diameter of stem) but also had the lowest survival due to the 2017 hurricane season. The site furthest from the shoreline (Reef Bay) had the greatest number of individuals flowering and fruiting. However, the populations were not regenerating. Our findings indicate that sites further away from the shoreline and of non-eastern aspect (similar to the orientation of Reef Bay) are optimal locations for establishing new populations of S. conocarpum.

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