No Effect of Variations in Overstory Diversity and Phylogenetic Distance on Early Performance of Enrichment Planted Seedlings in Restoration Plantations

Abstract

Enrichment planting is a strategy to increase tree diversity and reintroduce desirable species in restored forests, mainly in fragmented landscapes. However, the conditions that improve the performance of enrichment planted seedlings are not yet fully known. Here, we evaluate the role that overstory taxonomic diversity and mean overstory to seedling phylogenetic distance have as predictors of early performance of native tree seedlings planted beneath mixed-species restoration plantations in the Brazilian Atlantic Forest. By applying a phylogenetic approach, our study responds to recent calls for testing the application of such tools in restoration. We planted 12 mid- to late-successional species beneath a mixed-species restoration plantation with three nested tree diversity levels of 19, 58, and 107 species and estimated the mean phylogenetic distance between each seedling species and the overstory community. Seedling performance was not significantly affected by overstory diversity or mean phylogenetic distance. Overall good performance of the seedlings shows that enrichment planting beneath a mixed-species overstory can be successful even under variations in overstory species number and phylogenetic distance. However, significant species-specific differences in performance highlight the importance of an informed selection of which species to enrich plant.