Data and R Script for "Local spatial heterogeneity in alpine surface and krummholz tree cover regulates microclimates, plant growth-form cover, and species diversity" by MacDonald and Nielsen (2026)

The files included were used in the analyses for "Local spatial heterogeneity in alpine surface and krummholz tree cover regulates microclimates, plant growth-form cover, and species diversity" by MacDonald and Nielsen (2026). The manuscript has been submitted to Alpine Botany, and the authors are awaiting review. Data were collected at Cardinal Divide in Whitehorse Wildlands Provincial Park, Alberta, Canada in June - August 2024. The data contained in files labeled as " P#T_24HR.csv" or P#O_24HR.csv" were recorded by thermocouple (Perfect Prime TC0520) units using K-type, fibreglass-coated thermocouple wires spaced across 8 by 8 metre plots. Wires were placed within 1 cm of the ground surface and left to record for over twenty four continuous hours. The file "all.coords.csv" contains 401 gps coordinate points, which correspond to the 24-hour temperature measurement locations. The data contained in files labeled as "p#T.full.csv" or "p#O.full.csv" were created within the script. They are a combination of the 24 hour temperature data and the coordinates of each point, split by plot (open vs treed) and pair (1 through 8). The data in "CoverData.csv" are recordings of percentage species cover (species are listed as column names). The quadrat sizes represent nested quadrats, where the small (25 cm by 25 cm) was contained by the large (50 cm by 50 cm), both centred around the measurement point. Species names are listed as abbreviations, showing the first three letters of the genus followed by the first three letters of the specific epithet. Note that for unknown species, they are listed as UNK#. Additional data in this file are densiometer (canopy cover) recordings; vegetation height at the centre of the quadrat and the maximum vegetation height within the quadrat (any height above 200 cm is listed as 201); aspect; slope; soil depth (cm). The data contained in files labaled as "p#t.sar_data.csv" or"p#o.sar_data.csv" are output files, created within the script. They contain the species-area relationship data calculated using a for loop function in R, which was done as part of the analysis. The data in the .csv files were used to perform the analyses in the given R script. This analysis is part of Chapter 2 of the MSc thesis of Alexa A.C. MacDonald, being completed at the Applied Conservation Ecology Lab at the University of Alberta, under the supervision of Dr Scott E. Nielsen.