REGENERATION OF VEGETATION ON SANTA-FE AND PINTA ISLANDS, GALAPAGOS, AFTER THE ERADICATION OF GOATS

Analysis of 13 permanent sample plots (quadrats) in the Galápagos showed that recent elimination or reduction of the populations of feral goats has been followed by a regeneration of the vegetation. On Santa Fé, where the vegetation is dry season deciduous, goats were eradicated in 1971; since then the density of woody plants in the quadrats has increased. However, only about half the woody species present participate in the recolinisation, and some of the remaining species appear to have been reduced so much in number that re-establishment will be very slow or even impossible. On Pinta island about 40 000 feral goats were shot during the period 1971-1977 and it is estimated that only a few thousand are left. In the arial lowlands a rapid regeneration is under way: the density and number of woody plant species occurring in the quadrats is increasing. Almost all species of woody plants appear to have survived in sufficient numbers to enable recolonisation of the area as soon as the grazing pressure is diminished. Some of the species seem to increase in abundance by means of rapid growth and maturity, subsequent large seed production, and rapid establishment of seedlings. In the evergreen vegetation types of the humid highlands of Pinta a rapid regeneration is also taking place, but here much probably takes place as regrowth from old stems and rhizomes. Both the density and number of woody plant species is increasing, and at the same time the herb cover is changing into more fern-rich communities. © 1979.