Data from: Among-species overlap in rodent body size distributions predicts species richness along a temperature gradient

The associated data files and R script are all that is required to reproduce the analyses in the manuscript "A thermal gradient of trait similarity across North America," published in Ecography: https://onlinelibrary.wiley.com/doi/10.1111/ecog.03641
The following .csv files contain data required to reproduce the analysis, with raw unprocessed small mammal data from NEON, small mammal data that has been put through our QC code, mammal trait data compiled from different sources, and site-level environmental covariates: raw_NEON_mammal_data.csv, final_NEON_mammal_data.csv, mammal_traits.csv, site_covariates.csv
The following .csv files contain metadata describing the corresponding data file: final_NEON_mammal_data_meta.csv, mammal_traits_meta.csv, site_covariates_meta.csv. Each file lists the data sources. Please see documentation at neonscience.org for more information on the NEON small mammal trapping data.
The following .R file is an R script, tested under R/3.3.3, that contains code to reproduce the analyses in the manuscript: code_supplement.R
Below is the abstract:Temperature is widely regarded as a
major driver of species richness, but the mechanisms are debated. Niche theory
suggests temperature may affect richness by filtering traits and species in colder
habitats while promoting specialization in warmer ones. However, tests of this
theory are rare because niche dimensions are challenging to quantify along broad
thermal gradients. Here, we use individual-level trait data from a long-term
monitoring network spanning a large geographic extent to test niche-based
theory of community assembly in small mammals. We examined variation in body size among 23 communities of North
American rodents sampled across the National Ecological Observatory Network
(NEON), ranging from northern hardwood forests to subtropical deserts. We
quantified body size similarity among species using a metric of overlap that
accounts for individual variation, and fit a structural equation model to
disentangle the relationships between temperature, productivity, body size
overlap, and species richness. We document a latitudinal gradient of declining
similarity in body size among species towards the tropics and overall increase
in the dimensions of community-wide trait space in warmer habitats. Neither
environmental temperature nor net primary productivity directly affect rodent species
richness. Instead, temperature determines the community-wide niche space that
species can occupy, which in turn alters richness. We suggest a latitudinal
gradient of trait space expansion towards the tropics may be widespread and
underlie gradients in species diversity.