Data from: Succession and seasonality drive tropical butterfly assembly after an extreme hurricane
Data files
Mar 08, 2024 version files 17.91 KB
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abundances.csv
2.75 KB
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README.md
4.89 KB
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siteVariables.csv
5.38 KB
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speciesTraits.csv
4.90 KB
Abstract
We monitored butterfly communities in two Puerto Rican forests differing in structure to assess butterfly diversity, abundances, and community-level wing traits (size and color) over one year, beginning six months after Hurricane Maria. This dataset includes monthly species counts (abundances), species mean wing trait values, and site level characteristics including abiotic (temperature, humidity, canopy openness) and derived community-weighted mean metrics (i.e., functional diversity, and community-weighted mean trait values). Monthly sampling revealed no significant relationships between abundances and canopy openness or humidity; instead, species abundances fluctuated seasonally and were non-linearly correlated with temperature. In contrast, wing size and color were linearly correlated with changes in abiotic conditions, indicating that the hurricane differentially impacted larger-sized and functionally rare species. Specifically, wings were larger in cooler and more open conditions. Wing saturation was positively correlated with lower temperatures and negatively correlated with humidity. Our results suggest that, first, a functional approach may provide better insight into the factors mediating species responses to disturbances and, second, disentangling abundance seasonality from successional processes necessitates long-term monitoring.
README: Data from: Succession and seasonality drive tropical butterfly assembly after an extreme hurricane
https://doi.org/10.5061/dryad.ns1rn8q1g
The data files describe butterfly species abundances, and site abiotic variables (temperature, humidity, canopy openness, and calculated diversity metrics) per monthly sampling occurrence in two wet subtropical forests in Puerto Rico. In addition, species mean wing trait values are provided for a suite of size and color traits.
Description of the data and file structure
Three data files are included as comma-separated values files: abundances.csv, siteVariables.csv, and speciesTraits.csv.
abundances.csv has the following columns:
- date_YYYYMM: [numeric] The date of each sampling event, using the four-digit year and two-digit month.
- site: [text] The forest where sampling occurred.
- Then, 43 species are included as columns (integers) with the cell value indicating the number of individuals observed during each sampling event. Blank cells indicate no individuals were observed for a particular species during a particular sampling event.
speciesTraits.csv has the following columns:
- species: [text] Taxonomic names for 43 butterfly species
- length_cm: [numeric] Mean wing length (in centimeters)
- width_cm: [numeric] mean wing width (in centimeters)
- intensity: [numeric] mean wing color intensity
- hue: [numeric] mean wing color hue based on the HSB color space; unitless values from 0 to 255
- saturation: [numeric] mean wing color saturation based on the HSB color space; unitless values from 0 to 255
- brightness: [numeric] mean wing color brightness based on the HSB color space; unitless values from 0 to 255
- L: [numeric] mean wing color perceptual lightness based on the CIELAB color space; unitless values from 0 to 100
- a: [numeric] mean wing color in the green-magenta spectrum of human vision. Based on the CIELAB color space where negative values represent green and positive values represent magenta.
- b: [numeric] mean wing color in the blue-yellow spectrum of human vision. Based on the CIELAB color space where negative numbers represent blue and positive represent yellow.
- chroma: [numeric] mean wing chroma, or purity of a color in reference to a white standard.
siteVariables.csv has the following columns. Blank cells represent no data collected due to datalogger failure (for climate variables) or site inaccessibility (for sampling). Functional metrics and community-weighted means were calculated using a trait-by-species abundance matrix. *
- date_YYYYMM: [numeric] The date of each sampling event, using the four-digit year and two-digit month.
- site: [text] The forest where sampling occurred.
- temperature_degC: [numeric] Temperature in degrees Celsius, as measured by a datalogger.
- humidity_percent: [numeric] Relative humidity expressed as a percentage, as measured by a data logger.
- canopyOpenness_percent: [numeric] The degree of canopy openness expressed as a percentage.
- numIndividuals: [integer] The total number of individual butterflies observed during each sampling event.
- richness: [integer] The total number of butterfly species observed during each sampling event.
- FRic: [numeric] Functional richness
- FEve: [numeric] Functional evenness
- FDiv: [numeric] Functional diversity
- FDis: [numeric] Functional dispersion
- CWM_length: [numeric] Community weighted mean wing length (in centimeters)
- CWM_width: [numeric] Community weighted mean wing width (in centimeters)
- CWM_ratio: [numeric] Community weighted mean aspect ratio which is calculated as a ratio (therefore unitless) between wing length and width
- CWM_intensity: [numeric] Community weighted mean wing color intensity
- CWM_hue: [numeric] Community weighted mean wing color hue based on the HSB color space; unitless values from 0 to 255
- CWM_saturation: [numeric] Community weighted mean wing color saturation based on the HSB color space; unitless values from 0 to 255
- CWM_brightness: [numeric] Community weighted mean wing color brightness based on the HSB color space; unitless values from 0 to 255
- CWM_L: [numeric] Community weighted mean wing color perceptual lightness based on the CIELAB color space; unitless values from 0 to 100
- CWM_a: [numeric] Community weighted mean wing color in the green-magenta spectrum of human vision. Based on the CIELAB color space where negative values represent green and positive values represent magenta.
- CWM_b: [numeric] Community weighted mean wing color in the blue-yellow spectrum of human vision. Based on the CIELAB color space where negative numbers represent blue and positive represent yellow.
- CWM_chroma: [numeric] Community weighted mean wing chroma, or purity of color in reference to a white standard.
Methods
We monitored butterfly populations in two forests located in Puerto Rico’s Cordillera Central: Bosque del Pueblo and Bosque La Olimpia using nets, fruit bait traps, and visual counts. For visual counts, we performed standardized transect walks along a 2 km route, with approximately seven person-hours dedicated to sampling per month per site over one year.
We collected three individuals per species, usually one female, one male (when sex could be differentiated in the field), and an additional individual, to prepare as voucher specimens. All specimens were deposited at the Museo de Zoologia at the University of Puerto Rico-Rio Piedras (museum code: UPRRP). Furthermore, we measured the canopy cover using a fish-eye lens (ECO-FUSED, U.S.) attached to a smartphone and analyzed images using the Gap Light Analyzer application which calculates the percentage of occupied pixels and thus canopy cover. We also measured temperature and humidity using data loggers.
We photographed all voucher specimens using standardized protocols and used the resulting images to calculate wing size using image analysis software (ImageJ/FIJI). We measured two forewing traits on all specimens: wing length, calculated as the length in centimeters of the longest axis from the point of wing attachment at the thorax (disc cell) to the distal tip (R4 vein), and wing width, calculated as the width in centimeters of the longest line (R2 vein) that could be drawn perpendicular to the A2 anal vein. We also measured wing color using image analysis software on a 1 cm2 square area near the thorax, avoiding veins and regions with damaged or missing scales. We converted the raw RGB (red, green, blue) digital images to HSB images (hue, saturation, brightness, and intensity color space; Schindelin et al. 2012).
Next, to analyze functional community structure through time, we calculated community-weighted means (CWMs) and functional diversity metrics based on species composition, trait values, and abundances at each site at each sampling occurrence.