Data from: Wild bee abundance declines with urban warming, regardless of floral density
Data files
Jul 26, 2022 version files 18.58 KB
-
README.xlsx
9.33 KB
-
SiteData.csv
2.76 KB
-
SitesSpp.csv
6.49 KB
Dec 17, 2024 version files 322.91 KB
-
its_dryad.csv
295.33 KB
-
README.md
18.33 KB
-
SiteData.csv
2.76 KB
-
SitesSpp.csv
6.49 KB
Abstract
As cities expand, conservation of beneficial insects is essential to maintaining robust urban ecosystem services such as pollination. Urban warming alters insect physiology, fitness, and abundance, but the effect of urban warming on pollinator communities has not been investigated. We sampled bees at 18 sites encompassing an urban warming mosaic within Raleigh, NC, USA. We quantified habitat variables at all sites by measuring air temperature, percent impervious surface (on local and landscape scales), floral density, and floral diversity. We tested the hypothesis that urban bee community structure depends on temperature. We also conducted model selection to determine whether temperature was among the most important predictors of urban bee community structure. Finally, we asked whether bee responses to temperature or impervious surface depended on bee functional traits. Bee abundance declined by about 41% per °C urban warming, and temperature was among the best predictors of bee abundance and community composition. Local impervious surface and floral density were also important predictors of bee abundance, although only large bees appeared to benefit from high floral density. Bee species richness increased with floral density regardless of bee size, and bee responses to urban habitat variables were independent of other life-history traits. Although we document benefits of high floral density, simply adding flowers to otherwise hot, impervious sites is unlikely to restore the entire urban pollinator community since floral resources benefit large bees more than small bees.
https://doi.org/10.5061/dryad.qv9s4mwhz
Description of the data and file structure
Files and variables
File | Field | Explanation |
---|---|---|
SitesSpp.csv | Each column represents one bee species. Each row represents one site. The cell value is the number of bees caught at that site for that species, using all methods (pan trap, vane trap, netting) throughout the project. | |
SiteData.csv | column | definition |
site | site name (corresponds to “site” column in SitesSpp) | |
parcel_area_m2 | area of property on which sampling was conducted in square meters | |
sample_area_m2 | yard area sampled (parcel minus house, driveway, inaccessible areas) | |
temp | season-long mean evening (19:00 - 21:00) temperature for each site (degrees C) | |
flordiv | mean number of taxa in bloom across sampling dates | |
imperv100 | percent impervious surface within 100m radius of the center of the site | |
imperv200 | percent impervious surface within 200m radius of the center of the site | |
imperv1000 | percent impervious surface within 1000m radius of the center of the site | |
florabund | mean across sampling dates of estimated floral density at site (flowers per acre) | |
ln_florabund | florabund, natural-log transformed | |
all_rich | richness of all bees (rarefied to 100 individuals) | |
sm_rich | richness of bees with IT span < 2mm (rarefied to 75 individuals) | |
lg_rich | richness of bees with IT span ≥ 2mm (rarefied to 25 individuals) | |
all_abund | total number of individual bees caught at site | |
sm_abund | total number of bees of species with IT span < 2mm | |
lg_abund | total number of bees of species with IT span ≥ 2mm | |
lnall_abund | as above, natural-log transformed | |
lnsm_abund | as above, natural-log transformed | |
lnlg_abund | as above, natural-log transformed | |
its.dryad.csv | row | unique ID per row. Each row represents one individual bee. |
site | site name (corresponds to “site” column in SitesSpp and in SiteData; however, its.csv includes additional sites that were not part of the sampling for the main project, yet also had its measured. All sites are in Raleigh, North Carolina. Descriptive site names (e.g., ‘Across from Withers Hall’ are all located on NC State University campus) | |
genus | genus | |
species | specific epithet | |
sci_name | genus and species | |
sex | male, female, or ‘hermaphrodite’ | |
size_mm | body length (head to abdomen) in mm; ‘na’ for specimens not measured | |
its_mm | intertegular span in mm |