Genetic Consequences of Tropical Second-Growth Forest Regeneration

Genetic Consequences of Tropical Second-Growth Forest Regeneration


This article is an examination of the genetic impacts of old-growth deforestation among 24 year-old second-growth Iriartea deltoidea, a canopy palm, in a lowland Costa Rican forest. Iriartea is widely distributed throughout neotropical rainforests and displays a diverse range of size classes in mature forests. This species recolonizes second-growth forests with newly generated seeds, which are dispersed by birds and mammals.

Research goals & methods

This study employs parentage analysis and genotyping, using AFLP, of the entire founder generation (130 trees) to determine reproductive dominance and genetic diversity among Iriartea deltoidea re-growth. Genotypically similair trees are organized in spatial patches across 20 hectares of second-growth forest and 10 hectares of adjacent old-growth forest. Genotype diversity, genotype patch size, and parentage of second-growth and old-growth Iriartea deltoidea are compared in this article.

Conclusions & takeaways

The impacts of reproductive dominance in early successional forests are significant. Compared to old-growth trees, second-growth trees had lower genetic diversity and larger patches of similar genotypes. Generations of genetic dispersal will be required to restore diversity in secondary tropical forests.


Sezen UU. Genetic Consequences of Tropical Second-Growth Forest Regeneration. Science. 2005;307:891–891. doi:10.1126/science.1105034.


  • Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA.