ECOLOGY AND CONSERVATION OF SIDA EGGERSII (MALVACEAE), A RARE TREE OF THE VIRGIN ISLANDS

摘要

The ecology of the tree Sida eggersii Baker (Malvaceae) was studied from 1991 to 2001 on Guana Island in the British Virgin Islands (BVI). Known from less than 30 individuals since its discovery, the Guana Island population of S. eggersii increased from over 200 in 1991 to over 1100 in 2001, and I report smaller populations from other islands in the BVI. The species is most common in low-elevation, dry scrub habitat with a NE- to SE-facing aspect. Flowering and fruiting begin in and continue slightly past the winter wet season. The species appears to be relatively r-adapted, showing rapid maturation, high growth rates, and high population turnover. Maturation can require less than two years but appears to generally ensue at 4-5 years age. Growth rate (increase in stem diameter) is approximately 5.0 mm/yr in young plants but decreases to an average of 2.6 mm/yr in large specimens. Mortality was high, averaging 5 %/yr, but was not evenly distributed among years. Germination and mortality seemed to be highly influenced by hurricanes.