Seed functional traits as predictors of seedling establishment success in Brazilian tropical forest restoration

Abstract

Several ecological filters in deforested and degraded areas reduce seedling emergence and establishment and hinder ecological restoration by direct seeding. Understanding whether functional traits are related to a species' capacity to overcome these filters and predict their field performance might improve the success of direct seeding techniques for ecological restoration. We assessed eight seed functional traits of tropical tree species, seeking those that best explained their establishment success in direct seeding restoration projects. We analyzed a dataset from 52 studies that tested direct seeding techniques with tree species in Brazil. From each study, we collected the mean establishment percentage for all tree species. Seed mass, cotyledon function, and germination speed were the only functional traits that significantly affected the species establishment percentage in direct seeding restoration projects. Species with larger seeds, storage cotyledons, and faster germination had higher establishment percentages. Choosing species with these functional traits for seed mixes will provide higher establishment percentages and, consequently, improve restoration success by direct seeding techniques.