The decline of tree diversity on newly isolated tropical islands: A test of a null hypothesis and some implications

Six islands, each less than a hectare in area, were isolated in about 1913 from the mainland of central Panama by the rising waters of Gatun Lake. By 1980, the diversity of trees on all but one of these islands was far lower than on mainland plots of comparable size. A restricted subset of tree species has spread on these islands, notablyProtium panamense, Scheelea zonensis, Oenocarpus panamanus andSwartzia simplex. We constructed a null model...