The role of recruitment and dispersal limitation in tree community assembly in Amazonian forests

Washington Luis Oliveira et al. 2018. Plant Ecology and Diversity. DOI:10.1080/17550874.2018.1474960

Background: Species composition of plant communities is shaped by the interplay between
dispersal limitation, environmental filters and stochastic events.

Aims: The aim of this work was to investigate the effects of dispersal limitation and environmental
filtering on tree recruitment. To accomplish this, we employed the unified neutral theory of biodiversity
and biogeography to examine migration within the metacommunity, defined as a set of
interacting local communities linked by the dispersal of multiple potentially interacting species.
Methods: We sampled 12,975 individuals with dbh ≥ 1 cm in 26 1-ha permanent plots, including
habitats of terra firme, transitional forests, várzea and campinarana, on the upper Madeira River,
Brazilian Amazon.

Results: Campinarana drew individuals from outside the metacommunity species pool at a mean
probability of recruitment of 0.06, a much lower probability than terra firme (0.31), transitional
(0.21) and várzea forests (0.22). Environmental variables, such as water table depth, soil texture
and fertility, were related to differences in community assembly.

Conclusions: Species abundance distribution and diversity patterns of plant assemblages in a
large river landscape in the Amazon highlight the importance of environmental heterogeneity
that conditions beta-diversity. The high variation in recruitment probabilities from the metacommunity
species pool to local communities suggests high habitat variability in the process of
maintaining patterns of local diversity.

Várzea forest after exceptionally heavy flooding of the Madeira River in 2014 (c) Washington L Oliveira

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith