Data from: Configurational landscape heterogeneity shapes functional community composition of grassland butterflies

1. Landscape heterogeneity represents two aspects of landscape
simplification: (i) compositional heterogeneity (diversity of habitat
types) and (ii) configurational heterogeneity (number, size and
arrangement of habitat patches); both with different ecological
implications for community composition. 2. We examined how independent
gradients of compositional and configurational landscape heterogeneity, at
eight spatial scales, shape taxonomic and functional composition of
butterfly communities in 91 managed grasslands across Germany. We used
landscape metrics that were calculated from functional maps based on
habitat preferences of individual species during different life stages.
The relative effects of compositional and configurational landscape
heterogeneity were compared with those of local land use intensity on
butterfly taxonomic diversity, community composition and functional
diversity of traits related to body size, feeding breadth and migratory
tendency. 3. As expected, compositional heterogeneity had strong positive
effects on taxonomic diversity while configurational heterogeneity had
strong positive effects on trait dominance within the community. When
landscapes had smaller mean patch size and greater boundary area,
communities were dominated by species with more specialized larval
feeding, decreased forewing length and limited migratory tendency. 4. The
positive effects of increased configurational landscape heterogeneity
outweighed the negative effects of local land use intensity on larval
feeding specialization, at all spatial scales, highlighting its importance
for specialists of all dispersal capabilities. 5. Synthesis and
applications. We show that landscapes with high compositional
heterogeneity support communities with greater taxonomic diversity, while
landscapes with high configurational heterogeneity support communities
that include vulnerable species (feeding specialists with larger body
size, sedentary nature and more negatively affected by local management
intensity). A decline in functional community composition can lead to
functional homogenization, affecting the viability of the ecosystems by
decreasing the variability in their responses to disturbance and altering
their functioning. A landscape management for grasslands that promotes the
maintenance of small patch sizes and a diversity of land-uses in the
surrounding landscape (within 250–1000 m) is recommended for the
conservation of diverse butterfly communities. These strategies could also
benefit Government programs such as the EU 2020 Biodiversity Strategy in
their efforts to reduce the loss of biodiversity in agricultural
landscapes.