DOI: 10.7291/d15x0g
title: Data from: Effects of dispersal‐ and niche‐based factors on tree recruitment in tropical wet forest restoration

description: Both dispersal‐ and niche‐based factors can impose major barriers on tree
 establishment. Our understanding of how these factors interact to
 determine recruitment rates is based primarily on findings from mature
 tropical forests, despite the fact that a majority of tropical forests are
 now secondary. Consequently, factors influencing seed limitation and the
 seed‐to‐seedling transition (STS) in disturbed landscapes, and how those
 factors shift during succession, are not well understood. We used a 3.5‐yr
 record of seed rain and seedling establishment to investigate factors
 influencing tree recruitment after a decade of recovery in a tropical wet
 forest restoration experiment in southern Costa Rica. We asked (1) how do
 a range of restoration treatments (natural regeneration, applied
 nucleation, plantation), canopy cover, and life‐history traits influence
 the STS and (2) how do seed and establishment limitation (lack of seed
 arrival or lack of seedling recruitment, respectively) influence
 vegetation recovery within restoration treatments as compared to remnant
 forest? We did not observe any differences in STS rates across restoration
 treatments. However, STS rates were lowest in adjacent later successional
 remnant forests, where seed source availability did not highly limit seed
 arrival, underscoring that niche‐based processes may increasingly limit
 recruitment as succession unfolds. Additionally, larger‐seeded species had
 consistently higher STS rates across treatments and remnant forests,
 though establishment limitation for these species was lowest in the
 remnant forests. Species were generally seed limited and
 almost all were establishment limited; these patterns were
 consistent across treatments. However, our results suggest that
 differences in recruitment rates could be driven by differential dispersal
 to treatments with higher canopy cover. We found evidence that barriers to
 recruitment shift during succession, with the influence of seed
 limitation, mediated by species‐level seed deposition rates, giving way to
 niche‐based processes. However, establishment limitation was lowest in the
 remnant forests for large‐seeded and late successional species,
 highlighting the importance of habitat specialization and life‐history
 traits in dictating recruitment dynamics. Overall, results demonstrate
 that active restoration approaches such as tree planting catalyze forest
 recovery, not only by decreasing components of seed limitation, but also
 by developing canopy cover that increases establishment rates of
 larger‐seeded species.
description: We conducted this study at five ~1-ha sites in southern Costa
 Rica, a subset of the 13 replicate restoration sites of this long-term
 experiment, located between the Las Cruces Biological Station (8° 47'
 7" N, 82° 57' 32" W) and the town of Agua Buena (8°
 44' 52" N, 82° 56' 39" W). At the start of the study,
 from 2004-2006, we established three 0.25-ha (50×50 m) plots separated by
 a ≥5 m buffer at each site. Three restoration treatments: natural
 regeneration, applied nucleation, or plantation, were applied to one of
 the plots at each of the sites. At three of the five sites selected for
 this study, equivalent sized plots were established in adjacent remnant
 forests to serve as references