Effects of seed dispersal by animals on the regeneration of Bursera graveolens (Burseraceae) on Santa Fe Island, Galápagos.

ABSTRACT

The importance of animals as seed dispersers for Bursera graveolens (Burseraceae) was assessed by analysis of juvenileadult interplant distances on Santa Fe Island, Galápagos. The Santa Fe Bursera population consists of two non-overlapping classes old, large adults, and juveniles recruited since the exermination of feral goats in 1971. Juveniles occurred on a variety of substrate types, as well as under and away from woody vegetation. Most juveniles arise from seeds dispersed by animals; 86% of the juveniles were ≧3 m away from the crown of the nearest adult, and half were ≧7 m away. Although all juveniles occurred within 35 m of an adult Bursera, seed dispersal by animals is an important factor in the regeneration of B. graveolens on Santa Fe.