Increased reproductive trait diversity, evolutionary history and distinctiveness during the succession of tropical forest

Questions Do old-growth forests retain more evolutionary history and more reproductive trait diversity along the successional gradient? How similar are the phylogenetic branches and reproductive attributes at each phase? In which succession stages are distinct lineages of trees and shrubs present? Do distinct lineages have distinct traits? Is there a turnover of species, lineages and traits of trees and shrubs along the successional gradient? Location Atlantic Forest, Reserva Natural Guaricica (25 degrees 19 ' S, 45 degrees 42 ' W) and Reserva Natural das aguas (25 degrees 21 ' S, 48 degrees 46 ' W), Antonina, Parana, southern Brazil. Methods We assessed the variation of alpha and beta taxonomic, functional and phylogenetic diversities of tree and shrub communities along a successional gradient (phase 1, stand initiation phase, from 0 to 9 years old; phase 2, stem exclusion phase, 10-25 years old; and phase 3, understorey re-initiation phase, 25-200 years old). We also evaluated the occurrence of distinct lineages and traits related to seed dispersal and pollination. Results In addition to the expected change in species composition, lineages and trait states and values were replaced along the chronosequence, with stronger variation for trees. Old-growth forests harbor distinct lineages and traits and a greater amount of evolutionary history and functional diversity of reproductive traits. We also found that distinct lineages were those that performed distinct functions. Conclusions Our study showed that as the succession proceeds, turnover of lineages and traits occurred, with the understorey re-initiation stage harboring the largest taxonomic, phylogenetic and functional diversity. In addition, understories of the re-initiation stage are important for the occurrence of distinct lineages, such as magnoliids, and of distinct traits, such as large fruits and seeds, which highlights the importance of conservation of old-growth forests, and its preservation can prevent the loss of distinct evolutionary histories and functions.

Automated summary

The study found that turnover of lineages and traits occurred as succession proceeds, with the understorey re-initiation stage harboring the largest taxonomic, phylogenetic and functional diversity. Additionally, the occurrence of distinct lineages in the understorey re-initiation stage highlights the importance of conserving old-growth forests to prevent the loss of distinct evolutionary histories and functions.