Data from: Fire effects on bird communities from seasonally flooded forests along Amazonian black water rivers of the Negro River basin
Data files
Sep 09, 2026 version files 70.23 KB
Abstract
Aim: Fire significantly contributes to Amazonian degradation, with igapó forests (seasonally flooded by blackwater rivers) being especially vulnerable. Igapó forests support species adapted to seasonal flooding, making fire a critical threat to these specialized organisms. Birds, due to their habitat specialization, can provide insight into fire's impact on this environment. We investigated how fire events over time affect bird species richness and composition in igapó forests of the Negro River basin.
Location: Negro River basin, Northwest Amazon.
Methods: We conducted bird surveys at 55 sites using autonomous recorders, totaling 236,5 hours of recordings. Sites included 18 control areas (igapó forests without fire from 1984 to 2022) and 37 burned sites (fire occurrence from 1984 to 2017). We compared bird species richness and composition across igapó treatments and analyzed the effects of canopy cover and understorey density changes due to fire.
Results: Burned areas showed higher bird species richness than unburned areas. Species composition was more similar in areas burned more than 20 years ago compared to recently burned areas (<10 years), although full recovery was not achieved. Species replacement was the main component affecting beta diversity. Canopy cover was the only variable directly influenced by time after fire. Both bird species composition and richness were directly affected by time after fire, though composition was also indirectly influenced through canopy cover.
Main conclusions: Fire has a direct effect on species richness and composition. Canopy cover is more affected by time after fire than understorey density, also influencing bird species composition. A period of 38 years appeared insufficient for the full recovery of the bird community. Urgent measures for fire monitoring, preservation, and restoration of igapó remnants are essential.
https://doi.org/10.5061/dryad.jm63xsjjm
Overview
This dataset contains bird occurrence data collected in seasonally flooded forests (igapó) along the Negro River basin, Brazil. Sampling points were classified by fire history: Control (unburned), Recent fire, and Old fire.
File structure
The Excel file contains three sheets:
1. Matrix
- Rows: Sampling points (e.g., Jau_P01, Unini_P06)
- Columns:
- `N`: Point number
- `Point`: Point code
- `River`: River name (Jau, Unini, Barcelos)
- `Trat1`: Treatment category (Control, Recent, Old)
- `NTrat`: Numeric treatment code (0 = Control, 1 = Recent, 2 = Old)
- `Trat2`: Original treatment name
- `Year`: Year of fire
- `Fire`: Years since fire
- `Fire_ggplot`: Years since fire (rounded for visualization)
- `DensTotal`: Total vegetation density
- `DensMedia`: Mean vegetation density
- `Dossel%`: Canopy cover percentage
- `Richness`: Species richness per point (birds)
- Remaining columns: Bird species names (binomial). Values: 0 = absent, 1 = present.
2. Sites information
- `River
,Point,Lat,Long`: Geographic coordinates. Lat/Long values are rounded to one decimal place (approx. 11 km precision at the equator) following GBIF guidelines for species of conservation concern - `Years after fire`: Time since last fire (0 = control)
- `DensTotal
,DensMedia,Canopy%,Richness`: Same as above - `Year`: Year of fire or "Control"
- `Trat`: Treatment (Control, Recent, Old)
3. Species per sites
- `Family`: Bird family
- `Specie`: Species name
- `Unburned igapó`: Points where the species occurred in unburned forests
- `Burned igapó`: Points where the species occurred in burned forests
Special symbols in Species per sites sheet:
- `*` (asterisk after species name) = the species occurred only in unburned igapó (not recorded in burned areas)
- `**` (two asterisks after species name) = the species occurred only in burned igapó (not recorded in unburned areas)
- `***` (three asterisks inside the point lists) = the species was recorded in only one of the 55 sampling points (singleton occurrence)
Units and interpretation keys
- `DensTotal
andDensMedia`: vegetation density (no units, relative values) - `Dossel%
/Canopy%`: percentage (0–100) - `Fire
/Years after fire`: years (integer) - `Trat1`:
- Control = unburned
- Recent = burned ≤ 10 years before sampling
- Old = burned > 10 years before sampling
- `NTrat`: numeric version of Trat1 (0 = Control, 1 = Recent, 2 = Old)
- `Trat2`: simplified treatment (Control = unburned, Fire = burned, regardless of time since fire)
- All bird species columns: 0 = not recorded, 1 = recorded
We used autonomous recorders to survey bird species at 55 sampling points divided among control igapós (without a history of fire), igapós burned longer ago, and recently burned igapós. We compared the richness and species composition among the three igapó treatments and investigated how the vegetation structure affected by fire influenced the avifauna.