DOI: 10.5061/dryad.2fqz612x4
title: Temperature-driven homogenization of an ant community over 60 years in a montane ecosystem

description: Identifying the mechanisms underlying the changes in the distribution of
 species is critical to accurately predict how species have and will
 respond to climate change. Here, we take advantage of a late-1950s study
 on ant assemblages in a canyon near Boulder, Colorado, USA to understand
 how and why species distributions have changed over a 60-year period.
 Community composition changed over 60 years with increasing compositional
 similarity among ant assemblages. Community composition differed
 significantly between the time periods, with aspect and tree cover
 influencing composition. Species that foraged in broader temperature
 ranges became more widespread over the 60-yr period. Our work highlights
 that shifts in community composition and biotic homogenization can occur
 even in undisturbed areas without strong habitat degradation. We also show
 the power of pairing historical and contemporary data and encourage more
 mechanistic studies to predict species changes under climate change.
description: # Temperature-driven homogenization of an ant community over 60 years in a
 montane ecosystem ##
 Description of the data and file structure **GC Soil Data:** This dataset
 is the combined soil data. This includes Browne and Gregg’s (1969) soil
 moisture data and the contemporary soil moisture data. Column A is the
 "Collection Date" (written as mm/dd/yyyy) that soil samples were
 taken from the field. Column B is "Timeframe." This indicates
 whether the data is from the historical study or the contemporary study.
 Column C is the "Collection Time." Time was recorded for the
 contemporary samples, but was not documented historically. Column D is
 "Transect" which references whether the collection was made from
 transect 1 (T1) or transect 2 (T2). Transects used were taken from Browne
 and Gregg (1969). Column E is "Aspect" which corresponds to
 whether the sample was taken from the north-facing slope, south-facing
 slope, or the canyon bottom. Column F is "Point". Each transect
 had 3 points, one at each aspect location. Columns G through L go through
 the calculations of soil moisture which is found in Column M. **Tree Cover
 Data (Long):** This dataset is the calculated percent tree cover for each
 site within the Gregory Canyon area. Column A is the "Site"
 within Gregory Canyon (1-33). Column B is the "Aspect" that the
 site was categorized in (north slope, south slope, canyon bottom). Column
 C is the "Timeframe" that the data corresponds to (historical
 vs. contemporary). Historical percent tree cover was calculated from 1940
 aerial imagery. Contemporary percent tree cover was calculated from 2015
 satellite imagery. Column D is "Percent Tree Cover" for each
 corresponding site. **Weather Station:** This dataset is weather station
 data recorded daily from 1900 to 2022 in Boulder, CO. Weather station data
 taken from
 [NOAA](https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USC00050848/detail). Column A is the "DATE" (written as mm/dd/yyyy) that temperatures were recorded. Column B is "Max" which is the maximum temperature recorded for that day (in Celsius). Column C is "Min" which is the minimum temperature recorded for that day (in Celsius). Column D is the "YEAR" that the data was recorded. **Weather Station (Subset):** This dataset is weather station data recorded during the sampling years only (1957, 1958, 2021, 2022) taken from the same weather station as above. Column A is “DOY” which is the day of year that the temperature data was recorded on. Column B is the "Year" that the temperature data was recorded. Column C is the "Date" (written as mm/dd/yyyy) that the temperature data was recorded. Column D is "TMAX C" which is the maximum temperature in Celsius that was recorded for that day. Column E is "TMIN C" which is the minimum temperature that was recorded for that day recorded in Celsius. **Gregory Canyon Ant Data:** This dataset has ant collection data and microclimate information. Column A is the "Project" (BG = Browne & Gregg data; GCA = contemporary data collected in 2021; GCB = contemporary data collected in 2022). Column B is the "Date" (written as mm/dd/yyyy) that the data was collected. Column C is the "DOY" which is the corresponding day of year that the data was collected on. Column D is the "Year." Column E is the "Sampling Site" (1-33) that the data was recorded in. Column F is the "Aspect Initials" (CB = canyon bottom, NS = north-facing slope, SS = south-facing slope). Column G is the "Aspect" written out (Canyon Bottom, North Slope, and South Slope). Column H is the "Timeframe" that the data was collected in (Historical and Contemporary). Column I, "Lat", is the latitude in decimal degrees. Column J, "Lon", is the longitude in decimal degrees. Column K is "Elevation (m)" which is the elevation in meters of the collection location. For Columns L through P, Browne and Gregg (1969) did not have this data in their publication. Column L is the "Time" (24-hour clock). Column M is the "Air Temp." which is the recorded air temperature 6 inches above the ground using degrees Celsius. Column N is the "Surface Temp." which is the surface temperature recorded for each ant collection. Column O is the "Collection method" (hand, bait, aspirator). Column P is "Surface Forager." This column consists of yes or no. Answering yes means the ant was on the surface or in an open exposed area during collection. Answering no means the ant was not a surface forager and was collected in a thermally buffered environment (in a nest, underground, in litter, in a dead log, under bark, etc.). Column Q is the "Current Species" name for the ant collected. Column R is the "Genus" of the ant specimen collected. Column P is "Sp." which is the species of the collected ant specimen. Ant species names from Browne and Gregg’s (1969) were updated to current nomenclature. ## Sharing/Access information Data was derived from the following sources: * ## Code/Software All analyses were run in R, version 4.0.2.