We sampled the diversity of trees and shrubs, and built the rarefaction and accumulation species curve in 10 native forest fragments in southern Chile. Results indicated that: (1) there were 23 species in all sampled fragments, (2) species richness increased significantly with fragment size, (3) all fragments require a minimal sampling from 40 to 170 individuals to reach the maximum theoretical species richness, and (4) sampling richness was greater than that theoretically expected (20 species).