DOI: 10.5281/zenodo.8383839
title: Data from: 'Species traits to guide moth conservation in anthropogenic regions: a multi-species approach using distribution trends in Flanders'

description: These data are related to the investigation of species traits as a guidance for moth conservation in the highly anthropogenic European region of Flanders (northern part of Belgium) based on Multi-Species Change Indices (MSCIs).

Abstract



Insects appear to decline rapidly in recent decades. This so-called sixth mass extinction garnered significant media attention, raising public awareness.

Macro-moths—a species-rich and ecologically diverse insect group—face severe declines, particularly in urbanised and intensively farmed areas.

Flanders is a highly anthropogenic region, serving as a case study where the impact on macro-moths of stressors like intensive agriculture, industrialization and urbanization has been quantified through a recently compiled Red List. Here, for 717 macro-moth species, we calculated relative changes in distribution area between a reference period (1980-2012) and the subsequent period (2013-2022). By correlating these species-specific trends with ten key ecological and life-history traits, we calculated more general Multi-Species Change Indices (MSCIs).

These MSCIs showed that species associated with wet biotopes and heathlands declined on average by 20-25%, while (sub)urban species increased by more than 60%. Species feeding on lichens or mosses increased by 31%, while grass-feeding species decreased by 20%. Both very small (+34%) and very large species (+15%) increased, whereas medium-sized species decreased by 5%. Monophagous (+17%), migrant (+88%), and colour-invariable species (+5%) increased, while colour-variable species decreased (-8%). Finally, Holarctic (-21%) and Palearctic species (-5%) decreased, while Mediterranean (+27%) and Western-Palearctic species (+9%) increased.

Our trait-based approach identifies key threats and mitigation strategies for moths in anthropogenic regions, offering evidence-based insights for crafting efficient management recommendations and informed conservation policies to safeguard moth communities.
description: The dataset consists of seven files. The files are described below.

prop_data_per_trait_intermed.csv: gives the intermediate data with following columns:



species_nl: Dutch vernacular name of the species

n_grids: number of 5 x 5 km² grids in which the species was encountered

period: period of 1980-2012 (p1980_2012) or 2013-2022 (p2013_2022)

rel_prop: relative proportion of 5 x 5 km² grids in which the species was encountered

trait_name: name of trait

trait_value: value of trait linked to species


prop_data_per_trait_nozero_intermed.csv: gives the intermediate data where species with zero occurrences were removed with the same columns as the previous datafile.

prop_data_per_trait.csv: gives the processed data used for final analysis with additional columns compared to the intermediate datafile:



species_new: adjusted names for species that have two different trait values for the same trait

sum_per_period: number of 5 x 5 km² grid cells visited per period

n_spec: number of species per trait value


prop_data_per_trait_nozero.csv: gives the processed data where species with zero occurrences were removed with the same columns as the previous datafile.

sci_species_summary.csv: gives the summary data of the species change index (SCI) analysis with following columns:



species_nl: Dutch vernacular name of the species

sci.median: posterior median of the SCI

sci.lower: lower bound of the credible interval of the SCI

sci.upper: upper bound of the credible interval of the SCI

trend_course: course classification of the trend of the SCI

trend_fine: fine classification of the trend of the SCI

.point: point summary used for SCI (we calculated the median)

.interval: type of credible interval used for SCI (we calculated the quantile interval (= equi-tailed interval))

.width: with of the credible interval (we used 90 %)


msci_trait_summary.csv: gives the summary data for traits of interest of the multi-species change index (MSCI) analysis with columns already described above.

msci_draw_list_log.rds: is an R object that is a list containing dataframes for traits of interest with the posterior draws of the MSCI in the log scale.