Functional traits and habitat use: investigating community assembly in a montane community (Carabidae: Nebria)

The processes that influence community assembly, such as competition for resources and environmental filtering, are often scale-dependent and vary across ecotones. Trait-based ecology provides a useful framework for testing which ecological processes most strongly influence local community composition, especially across environmental gradients where species diversity varies. Where environmental filtering dominates, species distributions are expected to be defined by strong turnover along environmental gradients, with more similar species occupying more similar habitats. Where interspecific competition dominates, species are expected to diverge in relative abundance and resource utilization at sites, so species can co-occur. Here, we integrate measurements of functional traits, microhabitat usage, isotopic composition (δ15N and δ13C), and abundance to test the importance of environmental filtering and resource/habitat partitioning in shaping a montane ground beetle species assemblage (Ca..., Ecological surveys were conducted during the first three hours after night fell. Specimens were collected along 100 m length transects, parallel to the riverbed. Surveys were conducted by walking in parallel lines, normal to the 100 m axis of the transect, from the edge of the river to the edge of the forest habitat. For thermal preference assays, beetles acclimated to laboratory conditions for two weeks on a 12-hour light cycle in a 5°C refrigerator. They were allowed to traverse a lane on a table with a thermal gradient in a dark room. Their position was tracked using a thermal imaging camera. Desiccation assays were performed by starving insects for 48 hours (with access to water), and then placing the beetles in a plastic vial sealed with a canvas cloth. This vial was placed in a 50 mL Falcon along with Dririte. Beetles were weighed at 0, 8, 24, and 48 hours. For stable isotope composition, beetles were collected and immediately placed in ethyl acetate. Their elytra were collected a..., , # Functional traits and habitat use: investigating community assembly in a montane community (Carabidae: Nebria)

[https://doi.org/10.5061/dryad.vmcvdnd02](https://doi.org/10.5061/dryad.vmcvdnd02)

## Description of the data and file structure

In some files, \"eschscholtzii\" is misspelled \"eschschultzii\" and \"mannerheimii\" is misspelled \"mannerheimi\".

In general, rows are specimens, columns are variables. Any empty cells in datasets can be replaced with \"NA\".

FS1 includes environmental variables measured for each specimen collected during ecological surveys. Environmental variables included: Elevation (m), location (name of the river system), river name, aspect (north, south, etc.) of the mountain, latitude and longitude (WGS84), distance from the river's edge (m) where the specimen was found, surface temperature (C), habitat (substrate where the specimen was found), species identity, average ambient temperature during the survey (C), relative humidity during the survey (%), substrate...