Plants and Trees

The night-blooming cereus cactus flower, found in the dry tropical forests of St. John.

Virgin Islands National Park contains many tracts of undeveloped forests. According to the Conservation Data Center of the University of the Virgin Islands, the forest types of St. John can be broken down into the followinig categories: dry tropical, moist tropical, shrubland cover, woodland cover, herbaceous community, wetland community, and sparse vegetation. Many factors contribute to the variations of the forests. what grows where will be influenced by rainfall, wind, climate, topography, soils and even hurricanes.

Living in these forest communities are some 748 species of plants and trees. Of those, 642 are native to St. John. Native plants and trees are those that reached here without the help of people. Their seeds were carried by wind, waves or maybe birds to the island.

The dominant type of forest on St. John is dry tropical forest. It can be found on the eastern and southeastern portions of the island as well as low-lying coastal areas. It represents 50.51% of the forest community. Common trees of the dry forest are: turpentine (Bursera simaruba), water mampoo (Pisonia subcordata), wild frangipani (Plumeria alba), gris gris (Bucida buceras) and genip (Melicoccus bijugatus). Plants of the dry tropical forest include the night-blooming cereus cactus (Hylocereus trigonatus) and the wild pineapple (Bromelia penguin).

 

The century plant is an example of a shrubland cover species on St. John.

NPS photo/ A. Smith

The second most common forest type is shrubland cover. It represents 25.57% of the forest of St. John. Shrubland cover can be found in dry locations at low elevations. The vegetation in this forest type is often limited to those species that can tolerate exposure to extreme conditions like strong wind, salt spray and intense sunlight. Trees found here are the heiti heiti (Thespesia populnea), manchineel (Hippomane mancinella) and sea grape (Coccoloba uvifera). Cactus like the pipe organ (Pilosereus royenii) and succulents like the agave or century plant (Agave missionum) are also present.

The third most common forest type is moist tropical forest. It represents 10.43% of the forests of St. John. Moist forests receive more rainfall than any other forest type. Often there are guts located within the moist forest which flow with fresh water after a heavy rain. Moist forests contain the tallest trees on the island, some reaching almost 100 feet. Trees found in the moist forest include the kapok (Ceiba pentandra), sandbox (Hura crepitans), locust (Hymenaea courbaril), hog plum (Spondias mombin), teyer palm (Coccothrinax alta), mango (Mangifera indica) and bay rum (Pimenta racemosa).

 

Even though it only accounts for 1.8% of the forest on St. John, wetlands are an extremely important area. They are so important, wetlands are legally protected from disturbance and harm under Virgin Islands law. Wetlands are found near the coast in areas that periodically flood with rain or salt water.
Three species of mangroves can be found in our wetlands. They are red mangrove (Rhizophora mangle), black mangrove (Avicennia germinas) and white mangrove (Laguncularia racemosa).
Currently 31 species of St. John’s plants and trees are listed as threatened or endangered by the local or federal government. Hopefully with the park’s protection, the forests will continue to survive and some of the species in trouble will recover.
For a complete list of endangered plants and animals of the Virgin Islands, log on to the web page of the Virgin Islands Division of Fish and Wildlife at : www.vifishandwildlife.com.