DOI: 10.5061/dryad.sj3tx96b5
title: Defaunated and invaded insular tropical rainforests will not recover alone: recruitment limitation factors disentangled by hierarchical models of spontaneous and assisted regeneration

description: Most tropical forests are now severely degraded and their ability to
 recover is highly dependent on frugivores which ensure seed dispersal for
 most woody plants. The global collapse of large vertebrates therefore
 raises major concerns about tropical forest succession, but few field
 studies have been conducted to disentangle recruitment limitations during
 disrupted succession. This study took place on Réunion (Mascarenes) where
 all large native frugivores have been extinct since human colonisation in
 1665 and where multiple invasions threaten native ecosystems. We set up 20
 experimental blocks on a lava flow dated back to 1800, in
 plant-impoverished post-defaunation vegetation bordered by old-growth
 forests. We assessed fecundity, seed dispersal and seedling recruitment of
 the complete fleshy-fruited plant community and used Bayesian analyses to
 disentangle the impact of multiple factors on these key processes. In the
 same blocks, we sowed four native trees assumed to be disperserless to
 test their capacity to establish, controlling for two additional
 post-dispersal limitations (seed predation and competition with invasive
 plants). On the flow, small-seeded native plants were fairly dispersed but
 did not recruit, probably due to strong competition with invasive plants;
 the few native species that recruited somehow were mostly medium-seeded
 plants that were still dispersed; large-seeded plants were absent from
 seed rain (which shows that invasive frugivores did not replace extinct
 ones) and subsequently from spontaneous recruitment. Instead, some alien
 plants, notably the tiny-seeded highly-dispersed Clidemia hirta and the
 medium-seeded Psidium cattleianum largely dominated seedling recruitment.
 Native plants recruited better at the forest margin, including some
 large-seeded species nearby mother trees. Sown large-seeded species were
 able to emerge and survive in all plots whatever the treatment, which
 demonstrates that dispersal loss was the primary cause of regeneration
 failure on the flow.  Synthesis. The strong modulation of the
 establishment capacity of native plants by seed mass shows that invasive
 plants win by forfeit of large-seeded plants after native frugivores loss.
 Our study emphasises the fundamental role of dispersal loss and
 competition with invasive plants in the disruption of ecological
 succession, as well as the urgency of restoring seed dispersal and
 strengthening biosecurity regulations.
description: # Defaunated and invaded insular tropical rainforests will not recover
 alone: recruitment limitation factors disentangled by hierarchical models
 of spontaneous and assisted regeneration
 [https://doi.org/10.5061/dryad.sj3tx96b5](https://doi.org/10.5061/dryad.sj3tx96b5) ## Description of the data and file structure The data are structured in a spreadsheet containing 6 sheets: 'obs\_study\_process' presents process measurements (fruit production, seed dispersal, seedling recruitment) for the 50 plant species studied in the observational study; 'obs\_study\_plot' presents the data for the 40 plots in the observational study; 'exp\_sowing\_count' presents count data over time for the 4 species of the experimental sowing; 'exp\_sowing\_height' presents height measurements over time for the 4 species of the experimental sowing; 'species' presents the characteristics (taxonomy, traits, status) of the plant species from the observational and experimental studies; 'metadata' describes all the variables in the five preceding sheets.