The Flora of Krakatau

Abstract

THE eruption of Krakatau, from May 20 to the end of August 1883, which killed the vegetation of the three islands of the Krakatau group and destroyed some two thirds of the island of Krakatau itself, was perhaps the most important volcanic outburst, from the point of view of the biologist, that has occurred in historic times. Its biological importance is, of course, due to the fact that Krakatau is now one of a group of four (formerly three) islands in the middle of the Sunda Strait, Krakatau itself being 40 km. distant from the nearest point of west Java, and the same distance from the nearest point, Varkenshoek, of south-eastern Sumatra. The nearest island to the group is the volcanic Sebesy Island, some 13 km. to the north, where the vegetation was not wholly destroyed. If, as has generally been accepted,, the whole of the vegetation of the Krakatau islands was destroyed, then the study of the gradual reeoloniza-tion recently published by Dr. W. M. Docters van Leeuwen is of unique interest and importance. Krakatau's historic eruption, however, is only one of a series each of which, could it have been studied, would have afforded invaluable information as to methods of plant distribution. Prom the geological evidence, there was originally a single volcanic island in the Straits about 2,000 m. high. This was destroyed, and the three main remaining portions are represented by Krakatau, Verlaten and Lang Islands, surrounding a deep circular sea basin. This eruption was followed by another violent one, and later, by the fusion of the two volcanoes Perbuatan and Danan, the historic island of Bakata or Krakatau, 9 km. long and 5 km. broad, was formed, two thirds of which were erupted and dispersed in 1883. Recently Anak Krakatau has been erupted.