Species functional traits affect regional and local dominance across western Amazonian forests

Several studies have documented dominance by few species in Amazonian forests. Dominance patterns in contrasting forest habitats in lowland Amazonia have revealed that dominant species tend to be either locally abundant (local dominants) or regionally frequent (widespread dominants) but rarely both (oligarchs). However, the mechanisms underlying dominance remain unclear. Here, assuming that species traits reflect ecological processes that can lead to dominance, we asked across different habitat types whether: (i) dominance is defined by specific functional profiles and (ii) dominance patterns (local dominants vs. widespread dominants) are associated with different functional traits. We combined census data from 503 forest inventory plots across four lowland forest habitats in western Amazonia with trait information for 2600 tree species, encompassing data collected in the focal plots and data from published sources. We considered traits that relate to leaf, wood, seed and whole-plant st..., We used an extensive dataset consisting of 503 forest inventory plots, ranging from 0.025 to 0.213 ha, across different western Amazonian forests, from Colombia to Bolivia. Plots covered the four main habitat types found in western Amazonia proportionally to their extension in the region, with 76% in terra firme forests, 11% in floodplains, 7% in swamps and 6% in white sands. All trees ≥ 2.5 cm DBH were recorded and identified to species, representing a total of 93,719 individuals, and 2609 species. 
We defined dominant species as those that together account for 50% of the total relative abundance of each habitat type, following ter Steege et al. (2013) and Matas-Granados et al. (2024). We identified dominant species separately by habitat type. We defined two main aspects of dominance: (1) local abundance of dominant species, calculated as the mean local relative abundance (individuals of the species in a plot divided by total individuals in the plot), averaged across the plots whe..., , # Exploring different dominance patterns in western Amazonian forests from a functional trait perspective

[https://doi.org/10.5061/dryad.2280gb60q](https://doi.org/10.5061/dryad.2280gb60q)

### Excel file name = Traits_species_data.xlsx

14 sheets

\"Traits_values2\" sheet = compiled species mean trait values without separating by habitat type.

\"Legend_Traits_values2\" sheet = Legend for the Traits_values2 sheet.

\"Traits_values_FT\" sheet = compiled species mean trait values separated by habitat type.

\"Legend_Traits_values_FT\" sheet = Legend for the Traits_values_FT sheet.

\"Table_compilation\" sheet = Table where rows are the species of our study and columns are the functional traits that we studied. To each species and trait, we included the references where the functional data was extracted from.

\"Legend\" sheet = Legend for the Table_compilation sheet.

\"Workflow\" sheet = Steps followed to generate the compiled trait database.

\"References\" sheet = References from the functional data..., , **Changes after Nov 14, 2025:** We have included the compiled trait database with species mean trait values