On vegetation recovery, goats and giant tortoises on Pinta Island, Galápagos, Ecuador
Data on vegetational changes on Pinta Island, Galápagos, collected during the period 1970–1988, show that feral goats have had a destructive impact on the vegetation. Stands of Scalesia baurii ssp. hopkinsii (Asteraceae) and Opuntia galapageia var. galapageia (Cactaceae) were close to a complete collapse, while stands of Bursera graveolens (Burseraceae) apparently were able to persist for a longer time. After the elimination of large numbers of goats, Scalesia, Opuntia and Bursera were recovering rapidly, but the patterns of regeneration differed in accordance with differences in longevity, growth and seedling establishment.It is suggested that the absence of herbivores (the Pinta subspecies of giant tortoise is practically extinct, and feral goats were finally eradicated in 1990) in the long term may lead to decreased diversity in the vegetation of Pinta. As a management experiment aimed at conserving the biological diversity of Pinta, it is proposed to reintroduce giant tortoises to the island, preceded and accompanied by a careful long-term monitoring of vegetational changes.