Bee community and trait-based responses to fire in a Mediterranean landscape
Data files
Nov 12, 2025 version files 4.04 MB
Abstract
Fire is a major global disturbance affecting the evolution of organisms and shaping plant and animal diversity, especially in fire-prone regions like the Mediterranean. Yet its impacts on insect-pollinator communities remain poorly understood.
We conducted a 3-year study on a Greek island, examining spatial and temporal impacts of fire on bee communities and species’ functional traits. We compared bee diversity and population sizes in burnt and unburnt sites, by including in our analysis fire severity metrics using dNBR (differenced Normalized Burn Ratio) derived from satellite imaging.
We show that fire initially led to increased bee abundance despite having a strong negative impact on floral resources.
Burnt and unburnt communities differed significantly in species composition revealing that specific bee taxa drove post-fire recovery. In post-fire year 1, the population spike in burnt sites was driven by an increased abundance of below-ground nesters, excavators, and trophic generalists (polylectic); in contrast, the populations of trophic specialists (oligolectic) were negatively affected. By year 3, most differences between burnt and unburnt sites had been alleviated.
Multivariate models incorporating fire severity, plant diversity, and floral resources revealed that the heterogeneity of fire severity, even within small spatial scales, drove most of the variation in bee populations, followed by flower numbers.
Our findings highlight the role of fire as an environmental filter, selecting species with specific traits and shaping distinct post-fire communities. Notably, within three years, burnt bee communities started converging with the unburnt sites, suggesting a relatively rapid recovery of functional composition.
Metadata for the manuscript:
Title: Bee community and trait-based responses to fire in a Mediterranean landscape
Authors: Georgios Nakas, Aphrodite Kantsa, Lazaros Neokosmidis, Jelle Devalez, Thomas Tscheulin, Nikos Koutsias, Mark C. Mescher, Consuelo Μ. De Moraes, & Theodora Petanidou
Journal: Insect Conservation and Diversity
Information about the dataset:
We examined the effects of a wildfire on wild bee communities in a Mediterranean island system. Data were collected over three consecutive years at burnt and unburnt sites on Chios Island, North Aegean, Greece. We assessed changes in bee abundance, species richness, and functional traits, as well as their relationships with fire severity and floral resource availability across the post-fire landscape.
Data contain two files:
Nakas_et_al_Insect_Conservation_Diversity_Bee_Data.csv
- Family = The family of the bee species that was collected.
- Genus = The genus of the bee species that was collected.
- Species = The bee species that was collected.
- Site = Identifier of the study site. In total, we selected 13 sites (9 burnt and 4 unburnt). (For details, see also Figure 1 and Table S1 of the published article.)
- Fire regime = Identifier of the fire regime. B: Burnt, U: Unburnt.
- Year = Identifier of the year of collection. 2013: Year 1, 2014: Year 2, 2015: Year 3.
- Method = Identifier of the collection method (Pan traps and Hand netting).
- Round = Identifier of the round of collection: Round 1: April, Round 2: May, Round 3: June.
- Plant species = The host-plant species that bees were foraging on during hand-net sampling.
- Sociality = Sociality of the species (solitary, eusocial). (For details, see Table S2 of the published article.)
- Nest location = Nest location of the species (below ground, above ground, n/a). (For details, see Table S2 of the published article.)
- Nest construction = Nest construction of the species (excavate, rent, construct, n/a). (For details, see Table S2 of the published article.)
- Lecty = Lecty (oligolectic, polylectic, n/a). (For details, see Table S2 of the published article.)
Nakas_et_al_Insect_Conservation_Diversity_Flower_Cover_Data.csv
- Plant species = The plant species that was collected or recorded.
- Family = The family of the plant species that was collected or recorded.
- reproductive units = Total number of functional reproductive units per plant species (i.e., flowers or inflorescences depending on the species) was counted in each square.
- Site = Identifier of the study site. In total we selected 13 sites (9 Burnt and 4 unburnt) (For details see also Figure 1 and Table S1 of the published article).
- Fire regime = Identifier of the Fire regime. B: Burnt, U: Unburnt.
- Year= Identifier of the Year of collection. 2013: Year 1, 2014: Year 2, 2015: Year3.
- Round = Identifier of the Round of collection: Round 1: April, Round 2: May, Round 3: June.
- Square = Identifier of the number of the square in each site. Within each site, 25 squares of 1 m2 were randomly selected and the total number of functional reproductive units per plant species (i.e., flowers or inflorescences depending on the species) was counted in each square.