Data from: Local habitats matter most: scale- and species-dependent drivers of butterfly communities in agroecosystems
Abstract
Biodiversity responses to land-use and climatic change are shaped by processes operating across spatial and temporal scales. However, community-level patterns may mask substantial interspecific variation in how environmental drivers structure species assemblages in agricultural landscapes.
We assessed the relative importance of environmental variables measured at local and landscape scales in explaining butterfly occurrence and abundance. Specifically, we asked whether (1) the importance of drivers varies among species and through time, and (2) species with similar life-history traits show consistent scale-dependent responses.
We analysed butterfly monitoring dataset from agricultural landscapes, combined with environmental covariates including local habitat characteristics, landscape composition, and climate and weather variables. Using hierarchical modelling of species communities, we quantified species-specific responses and evaluated changes in driver importance across four time periods.
Local habitat variables, including nectar plant availability and transect location, were the most important predictors of occurrence and abundance for most species. However, species differed markedly in both the direction and magnitude of their responses. The relative importance of drivers changed over time: land-use variables increased in importance, whereas climate and weather variables declined at the community level. Trait-based groupings revealed some scale-dependent patterns, particularly for overwintering stage and voltinism, but responses were not consistent across functional groups. Community-averaged responses therefore obscured substantial interspecific variation.
Our results demonstrate that butterfly community dynamics in agricultural landscapes are structured primarily by local habitat conditions, but in species-specific and temporally dynamic ways. Accounting for cross-scale and interspecific variation is essential for landscape management and biodiversity conservation planning.
Dataset DOI: 10.5061/dryad.wstqjq31d
Description of the data and file structure
Butterfly monitoring data from the Åland Islands from 2002, 2011, 2017, and 2022. Data was collected seven times each summer during the months from May to August using a standard butterfly transect monitoring protocol. Data was collected from 10 study areas ("Transects") which were divided into 20 smaller 50 m fragments ("Sections").
Environmental data was collected during the monitoring according to the monitoring protocol of the Finnish Environment Institute (SYKE), extracted from Corine Land Cover data and from meteorological data from the Finnish Meteorological Institute (FMI), and combined into a single dataframe.
Files and variables
File: Data.zip
Description: This folder includes all the data files needed to re-create the analysis and plots in Riihimäki et al. (2026). Datafiles include:
- Butterfly data matrix: "Butterflies_matrix.csv" - this file includes the butterfly abundance recorded during the study years with the following variables: "Year" = study year, "Transect" = 1 km transect line within the study area, "Section" = a 50 m fragment of the longer transect line, "Day" = day of the month, "Month" = month of the year. Each species has its own column where abundances are recorded; empty cells mean no individuals were recorded at that time.
- Environmental data matrix: "Environmental_matrix.csv" - this file includes all the environmental covariates used in the analyses. For more details on the different covariate classes, see the supplementary materials of the article. Local habitat variables according to SYKE classifications: "Habitat_type" = habitat type of the fragment, "Location" = position of the fragment, "Nectarplants_june" = amount of nectar plants in June, "Nectarplants_july" = amount of nectar plants in July, "Nectarplants" = average of June and July. Landscape variables derived from CLC data: "Year_corine" = CLC data year, "Forest_0.5" = amount of forest at 500 m buffer, "Forest_1.5" = amount of forest at 1.5 km buffer, "Forest_2.5" = amount of forest at 2.5 km buffer, "Grassland_0.5" = amount of grassland at 500 m buffer, "Grassland_1.5" = amount of grassland at 1.5 km buffer, "Grassland_2.5" = amount of grassland at 2.5 km buffer, "Ent_0.5" = landscape entropy at 500 m buffer, "Ent_1.5" = landscape entropy at 1.5 km buffer, "Ent_2.5" = landscape entropy at 2.5 km buffer. Local weather variables according to SYKE protocol: "temp_start" = temperature at the start of the monitoring occasion, "wind_start" = windiness at the start of the monitoring occasion, "cloud_start" = cloudiness at the start of the monitoring occasion. "SampOcc" = monitoring occasion with day.month.year format. Climate variables derived from FMI data: "GDD5s" = growing degree days, "precSum" = precipitation.
- Butterfly traits: "Butterfly_traits.csv" - this file includes all the traits used for the study species. "Body_size" = wingspan in mm; "Overwintering" = overwintering stage: egg, larva, pupa or adult; "Host_plant" = host plant breadth: monophagous, oligophagous or polyphagous; "Voltinism" = generations per year: 1, 2 or 3; "Wing_size_class" = categories for wing size classes: < 30 mm, 30-45 mm or >45 mm.
- Diversity indices calculated for each transect and transect section: "shannon_diversity_section.csv" - file for diversity indices calculated for each section (i.e. 50 m transect fragment), "shannon_diversity_transect.csv" - file for diversity indices calculated for each full 1 km transect (i.e. study area).
- Phylogenetic tree for the study species (only used for plots): "Lepidoptera_pruned_full_names.nwk" - Newick format phylogenetic tree.
File: Code.zip
Description: This folder includes all the scripts needed to re-create the HMSC analysis, variance partitioning calculations, diversity analysis, and plots in the manuscript and supplementary materials.
Code/software
Codes are written in R Markdown style and can be run using R. Each script has a description on the first few lines of what it was used for.
Access information
Other publicly accessible locations of the data:
- Butterfly data also available at the Finnish biodiversity info facility https://laji.fi/
Data was derived from the following sources:
- Butterfly data for years 2002, 2011 and 2017 was provided by the Finnish Environment Institute (SYKE), Nature Solutions unit
- Corine Land Cover data (Feranec, 2016), as available for years 2000, 2012 and 2018
- Finnish Meteorological Institute weather data (Aalto, Pirinen, & Jylhä, 2016)
- Butterfly traits were gathered from Komonen (2004), Pöyry (2008), and Pöyry (2017)