Data from: Skyglow and especially direct streetlight pollution alter moth communities

Van de Schoot, Evert 1 ; Wesselingh, Renate A.1 ; Van Dyck, Hans1

Research facility: UCLouvain

Published Apr 01, 2025 on Dryad. https://doi.org/10.5061/dryad.6djh9w1d2

Data files

Apr 01, 2025 version files 925.97 KB

EVdS_et_al-EnvPol.zip
922.17 KB
README.md
3.80 KB

Abstract

Light pollution caused by artificial light at night (ALAN) affects biodiversity worldwide and is still increasing. Species vary in their response to ALAN, but the impact on communities remains poorly understood. Effects of indirect light pollution by skyglow and direct streetlight pollution on communities have usually been addressed separately, and in most studies so far, urbanisation levels are a confounding factor for ALAN effects per se. Here, we sampled garden moth communities according to a study design that integrated two levels of direct streetlight pollution and two regional skyglow levels to test for additive effects of both types of ALAN. We also tested whether ALAN conditions related to community changes in species’ morphological, behavioural and life-history traits. Both skyglow and streetlights negatively affected moth abundance. Species richness and diversity decreased under direct streetlight, independent of skyglow levels. Both types of ALAN affected moth community composition, and we identified several relationships with species traits in the local moth communities. Skyglow filtered for hibernating stage and larval habitation, while streetlight pollution filtered for voltinism, larval food specificity, habitat openness, and hibernating stage. Our study provides evidence that both skyglow and, more strongly, streetlight pollution affect moth communities. A significant decline in moth abundance will have consequences for ecosystem functioning through reduced food availability for predators and diminished pollinator services. At the community level, ALAN operates as a filter for species and species traits, and based on our results, we argue that future studies should consider both skyglow and direct light pollution.

Dataset DOI: 10.5061/dryad.6djh9w1d2

Description of the data and file structure

The dataset “EVdS et al-EnvPol.xlsx” contains: moth abundance data from gardens under different skyglow levels and with or without nearby streetlights; environmental data for each garden; moth species traits. Moths were sampled in collaboration with citizen scientists, using both light and bait traps. Light trapping took place on pre-defined nights; moths were photographed by the volunteers ,and moths were identified by the first author using local literature. Bait traps remained continuously active for several days; trapped moths were collected by the authors and identified using local literature and moth genitalia examination. All missing data given as NA.

Files and variables

File: EVdS_et_al-EnvPol.zip

Description: This dataset contains all data used for our analyses in the R-script (“EVdS et al-EnvPol.R”). It contains: moth abundance data per sampling; environmental data for each garden; species trait data.

Sample: Moth abundance data for each individual sampling.

Trap: Pooled abundance data per garden per trap type.

Site: Pooled abundance data per garden.

LedBait: Pooled abundance data per trap type.

Cond: Pooled abundance data per light pollution condition per trap type.

FMSample: Abundance data for each individual sampling; for species trait analysis.

FMSample01: Presence/absence data for each individual sampling; for species trait analysis.

Trait: Species trait data

Variables abundance/presence-absence data:

Skyglow: skyglow level at sampling site. Low = low-medium; high = high-medium.
SL: Yes = nearby streetlight present; No = no nearby streetlight.
SQM: Sky Quality Meter (mag./arc sec²).
NearestSL: distance between sampling site and nearest streetlight (m).
Trap: trap type.
Day: day of the year sampling took place (light trap) or began (bait trap).
SL400: number of streetlights within 400 m of the sampling site.
BA400: built-up area within 400 m of the sampling site (%).
Area: garden area (m²).
Forest400: forested area within 400 m of the sampling site (m²).

Variables trait data:

Spec: scientific species name.
Species: abbreviation species name.
Family: moth family.
FWL: mean forewing length (mm).
FWLmin: minimal forewing length (mm).
FWLmax: maximal forewing length (mm).

(For the following variables, 1 = yes; 0 = no)

Monov: monovoltine.
Biv: bivoltine.
Multiv: multivoltine.
Cover: prefered habitat openness.
Hibern: hibernation stage.
Larva: larval habitation.
Monoph: monophagous.
Oligoph: oligophagous.
Polyph: polyphagous.
AdultTwilight: adult active at twilight.

File: EVdS_et_al-EnvPol.R

Packages: readxl, vegan, car, effects, lme4, lmerTest, BAT, ggplot2, ggthemes, gridExtra, egg, ggeffects, ggbiplot, blmeco, emmeans, ggVennDiagram
Functions:
- sumSE: function to calculate group means and standard errors. These are also used to produce the graphs.
- Size…: funcions to set figure sizes.
Statistical tests:
- Environment ~ Treatment: test to verify whether environmental variables differ between light pollution conditions.
- Diversity: test differences in diversity measures between light pollution conditions.
- perManova: perManova to test differences in community composition between light pollution conditions.
- NMDS: visualisation of differences in community composition between light pollution conditions.
- CWM: test differences in community-weighted means of moth species traits between light pollution conditions.
Figures: contains the script to produce the graphs.