The "Alpine" Plants of the Antilles

Abstract

Although few mountains of the Antilles are over 5000 ft, some of them do possess a distinctive type of vegetation near the summit. Mountains such as Mt. Pelee, the Soufriere of Guadeloupe, or the Soufriere of St. Vincent have been active volcanoes in the present century, and the reduced scanty or restricted vegetation there may be due to past and present volcanic fumes or rapid percolation of water on ashy substrata. The reduced elfin vegetation of other mountains has been attributed to effects of persistent wind, persistent cloud cover, colder temperatures, or saturated soils. Studies of the elfin forest on Pico del Oeste (3050 ft) in Puerto Rico have supplied information on both the environment of the mountain top and the composition of the forest type. After a full year of study it was shown that the rainfall was 453 cm; that clouds enveloped the peak 100 percent of the nighttime hours and 60 percent of daylight hours with the average relative humidity 98.5 percent. Clouds supplied an additional 10 percent to the total rainfall. Wind speed raniged from 8 to 11.1 knots. The average mean temperature was 17.4 degrees C and the soil 18.3 degrees C. Growth patterns of individual plants showed an abundance of long shoot-short shoot stems; dichotomous branching and pagoda branching. Insect damage to leaves was high, reducing the photosynthetic potential of the forest. Fertility was very low as recorded in pollen viability and seed set. THE ISLANDS OF the Lesser Antilles in the Caribbean area possess volcanic cones which range in altitude from the 1950-foot St. Eustatius in the north to the 2749 feet of Mt. Catherine on Grenada in the south,