Understanding different dominance patterns in western Amazonian forests

Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥ 2.5 cm diameter, 2,609 species) to explore the relationships between local abundance, regional frequency, and spatial aggregation of dominant species in four main habitat types in western Amazonia. Contrary to the widely supported positive abundance-occupancy relationship in ecology, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade-off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unraveling diff..., We used data from 503 forest inventory plots spread across western Amazonia, from Colombia to Bolivia. A total of 363 plots had an area of 0.1 ha, 134 plots were smaller than 0.1 ha (range from 0.025 to 0.08 ha), and 6 plots were larger (range from 0.128 to 0.213 ha). Plots are included in the RedGentry network. Across all plots, we measured stems with a diameter at breast height ≥ 2.5 cm within the plot limits. Plots covered the main four habitat types in western Amazonia: 383 in terra firme (76%), 54 in floodplain (11%), 35 in swamp (7%) and 31 in white sand (6%) forests.
We excluded all individuals not identified to species level (mean 14% of individuals per plot), since plot data came from different projects and morphospecies were not cross-checked. We also excluded individuals from doubtful identifications, e.g. ‘cf.’ and ‘aff.’ (mean 3% of individuals per plot). To the remaining individuals, we checked species names for synonym and spelling mistakes, using the R package ‘Taxonstan..., , # Title: Understanding different dominance patterns in western Amazonian forests

Dryad doi: https://doi.org/10.5061/dryad.pk0p2ngsd

NOTE:

* Version two published Sep 26, 2023 includes a revised R script file in Zenodo. No files on Dryad changed.
* Version three published Oct 17, 2023 includes additional raster and shape files.
* Version four published Oct 18, 2023 includes a revised R script file in Zenodo and a revised Raw\_to\_ecology3.csv file.

## Data frame name: Raw\_to\_Ecology3.csv

93719 rows = each plant individual

5 columns =

1. Cod\_plot: unique identifier of each plot
2. Species: plant genus and species name for all dominant species found in the research. Morphospecies for the non-dominant species
3. Forest\_type: Habitat type classification (Terra firme, Floodplain, Swamp, White sand)
4. Latitude: latitudinal geographic coordinates in decimal degrees
5. Longitude: longitudinal geographic coordinates in decimal degrees

## Data frame name: Metadata4.csv

503 rows = eac...