Soil characteristics and glacial history structure ground-nesting bee communities
Data files
Jun 17, 2026 version files 1.60 MB
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CavityNestersMatrix.xlsx
303.58 KB
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GroundNestersMatrix.xlsx
847.86 KB
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README.md
4.95 KB
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SoilAnalysis.R
29.29 KB
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SoilCharacteristicDataset.xlsx
399.79 KB
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Trait.Dataset1.xlsx
12.19 KB
Abstract
Global bee declines have intensified the need to understand the environmental drivers structuring bee communities. Although most bee species nest below ground, soil characteristics are an understudied determinant of bee diversity. Soil directly shapes the nesting microenvironment, likely acting as an environmental filter on ground-nesting bee communities. Large-scale patterns of soil variation, including the legacy of glacial events, may represent under-recognized drivers of bee diversity. We investigated how soil characteristics shaped by glacial history influence ground-nesting bee richness, species composition, and trait composition across Ohio, USA. We collected bees using pan traps at 141 sites and related bee richness and composition to soil variables extracted from the Soil Survey Geographic Database (SSURGO). Our models supported soil texture as a major driver of bee diversity, with ground-nesting bee richness declining with increasing clay content, and community composition structured by sand content. We further showed that soil characteristics filter ground-nesting bee species differently based on traits associated with their nesting ecology, particularly phenology and sociality. Bee community composition also varied along gradients of slope and soil pH, patterns that reflect the influence of landscape-scale glacial history. Glacial history influenced species and trait composition, indicating that glacial legacies continue to shape contemporary bee communities through their effects on soils. These results underscore the role of soil as a fundamental driver of bee diversity across landscapes and demonstrate the influence of glacial history in shaping contemporary ground-nesting bee communities.
Dataset DOI: 10.5061/dryad.9s4mw6mz6
Description of the data and file structure
Bee speciments were collected from May-October in 2020 using pan trap surveys at 141 locations across Ohio. Each site was sampled an average of 13.3 times over the year. At each sampling event, collectors placed 24 fluorescently painted bowls (~96 mL, eight each of yellow, blue, and white) five m apart on the ground in alternating colors along a transect. Each bowl was filled to two‑thirds capacity with soapy water (blue Dawn or equivalent unscented store brand) and left in place for 24 h before collection.
We extracted soil variables from the Soil Survey Geographic Database (SSURGO). We obtained soil data from the United States Department of Agriculture (USDA) for all counties in Ohio. Because the SSURGO dataset variables are reported per soil horizon, we restricted our request to horizons within the upper boundaries < 50 cm below the surface to capture depths relevant to bee nesting, which occurs on average between 17–35 cm below the surface (Cane & Neff, 2011). Of the soil horizons within our 50-cm cut-off, we calculated the mean value of each variable from all soil horizons per map unit to be joined with the 10 x 10 m map unit raster in ArcGIS Pro. We obtained slope and aspect data using the Terrain: Slope in Degrees imagery layer and Terrain: Aspect Map from ArcGIS Living Atlas, converting them into static raster layers suitable for spatial analysis.
We also extracted the proportion of forest (deciduous, evergreen, and mixed forest categories), developed land (high, medium, and low intensity categories), and agricultural land (pasture and cultivated crops categories) within the same three radii of site centers using the National Landcover Database in Arc GIS Pro. Climate variables were obtained from the WorldClim (version 2) dataset.
Files and variables
File: SoilAnalysis.R
Description: R code for analysis and visualization
File: CavityNestersMatrix.xlsx
Description: Matrix of cavity-nesting species by sample per site.
Variables
- Each column is a species name
File: GroundNestersMatrix.xlsx
Description: Matrix of ground-nesting species by sample per site.
Variables
- Each column is a species name
File: Trait.Dataset1.xlsx
Description: Traits for species used for analysis. for citations for where the information on each trait came from please refer to table S1 in the cooresponding manuscript.
Variables
- Species
- Sociality.Simple - sociality either as social or solitary
- Season - phenology either as summer or spring based on the month of peak activity in GBIF from each species from preserved specimen in Ohio and surrounding states in the Midwest.
- AvgIT - average intertegular distance
File: SoilCharacteristicDataset.xlsx
Description: Soil characteristics, landscape variables, climate variables, and bee richness and abundance per site.
Variables
- Number - site number
- Latitude and longitude
- Glacier - whether the site was previously glaciated in the last 2 glacial maxima
- pH - soil pH average within 1000 m buffer of the site
- Sand - sand content average within 1000 m buffer of the site
- Silt - silt content average within 1000 m buffer of the site
- Clay - clay content average within 1000 m buffer of the site
- FragVol - Rock Fragment Volume average within 1000 m buffer of the site
- Ksat - saturated hydraulic conductivity average within 1000 m buffer of the site
- Bulk.Density - Bulk Density average within 1000 m buffer of the site
- Slope - Slope average within 1000 m buffer of the site
- AspectSE - average within 1000 m buffer of the site of slope aspect facing south, east, or southeast
- Organic - organic material content average within 1000 m buffer of the site
- Developed - high, low, and medium categories of developed land average within 1000 m buffer of the site
- Forest - mixed, deciduous, and coniferous forest average within 1000 m buffer of the site
- Ag - pasture and crop land average within 1000 m buffer of the site
- Samples - number of samples taken per site
- Ground.Richness - raw richness of ground-nesting species
- GB.Rare.7 - rarified ground-nesting richness to 7 samples per site
- Ground.Abundance - raw ground-nesting species abundance
- Cavity.Richness - raw richness of cavity-nesting species
- CB.Rare.7 - rarified cavity-nesting richness to 7 samples per site
- Cavity.Abundance - raw Cavity-nesting species abundance
- Richness - total richness
- Abundance - total abundance
- Precip.CM - average precipitation in centimeters
- AvTempC - average temperature in Celsius
Code/software
File "SoilAnalysis" includes R code to conduct analyses and visualizations. All names of files should align with those uploaded here.