Trait‐based species selection for restoration: A case study from tropical landscapes dominated by bracken

Abstract

Abstract Deforestation leads to non‐forested areas that often need active ecological restoration to promote forest succession. Here, we developed a trait‐based approach to guide the design of restoration projects and tested our approach in tropical areas deforested by fires and dominated by bracken. Deforestation caused by human‐induced fires creates complex conservation problems in tropical areas. After fire, montane tropical deforested areas are often dominated by bracken fern ( Pteridium spp.), which prevents the establishment of many species of trees. This means that effective ecological restoration strategies are needed for forest recovery. We explored whether a trait‐based approach could be used to guide the selection of tree species in active restoration projects in deforested areas. We first tested whether traits could be used to predict which species can overcome bracken‐associated filters. We then tested the relationship between the trait‐based predictions for each species and their abundance in a reference old‐growth forest. To identify key traits, we conducted a seed addition experiment in bracken‐dominated areas that had developed 5–15 years after a fire, using 23 tree species common in the Bolivian montane forests, and monitored seedling establishment, survival and growth for 36 months. We then related seedling performance to the functional traits of adults and seedlings. We found that six functional traits improved tree seedling performance in bracken‐dominated areas, and that only one third of the species evaluated exceed a 25% probability of recruitment. Most of the favoured traits correspond to conservative strategies. The species dispersed by birds and with large seeds were the most likely to overcome the filters created by bracken. Based on the trait predictions, we found that the species predicted to overcome bracken are not common in old‐growth forests. Synthesis and applications . Our results can be used by stakeholders to select the species best suited for active restoration projects in bracken‐dominated areas throughout the tropical region. Furthermore, our trait‐based approach, which considers seedling performance in disturbed areas, can serve as a guide for species selection in restoration programmes in other disturbed systems.