Dataset Title: Data for Dancing Name and contact information of PI: a. Name: Joseph D. Birch b. Institution: Department of Renewable Resources, University of Alberta, Edmonton, Alberta c. Address: 442 Earth Sciences Building, Department of Renewable Resources, University of Alberta; Edmonton, Alberta, Canada T6G 2E3 d. Email: coope456@msu.edu e. ORCiD ID: 0000-0001-8644-7345 Name and contact information of Co-PI: a. Name: James A. Lutz b. Institution: Department of Wildland Resources, Utah State University, Logan, Utah c. Address: 5230 Old Main Hill, Logan, Utah, 84322-5230, USA d. Email: james.lutz@usu.edu e. ORCiD ID: 0000-0002-2560-0710 Name and contact information of Co-PI: a. Name: Justine Karst b. Institution: Department of Renewable Resources, University of Alberta, Edmonton, Alberta c. Address: 442 Earth Sciences Building, Department of Renewable Resources, University of Alberta; Edmonton, Alberta, Canada T6G 2E3 d. Email: karst@ualberta.ca e. ORCiD ID: 0000-0003-0497-1552   Funding source (Agency, Grant Number): Funding was received from the Natural Science and Engineering Council of Canada to JK, and by the Utah Agricultural Experiment Station (projects 1153 and 1398 to JAL). Research was performed under National Park Service research permits CEBR-2014-SCI-0001, CEBR-2015-SCI-0001, CEBR-2016-SCI-0001, CEBR-2017-SCI-0001, CEBR-2018-SCI-0001, and CEBR-2019-SCI-0001 for study CEBR-00016 and permits CEBR-2018-SCI-0002 and CEBR-2019-SCI-0002 for study CEBR-00020 Abstract: 1.Background Fungal communities can influence the productivity, composition, and survival of trees through cycling nutrients, providing resources, and altering pathogens. Thus, shifts in fungal communities could impact forests by altering interactions between trees and their environments. Fungal community composition may be shaped by stochastic and deterministic processes such as dispersal-limitation, environmental filtering, and partner specificity between trees and fungi. For tree species with large geographic ranges, we expect fungal assembly processes to change with environmental variation across the range of the tree partner. Due to specificity between trees and symbiotic fungi, we expect deterministic to outweigh stochastic processes in root compared with soil fungi. As some tree species have exceptional longevity, we also expected tree age to influence fungal community assembly. 2. Methods We surveyed fungi in four stands of Pseudotsuga menziesii with tree ages up to 800 years along an 1,800 km north-south transect. We sampled roots and soil around 12 P. menziesii in each stand, aged the trees, and sequenced fungal rDNA to determine composition and richness from which we calculated the relative role of deterministic and stochastic assembly processes. We used null models to evaluate the relative importance of deterministic variable and homogenizing selection, and stochastic dispersal-limitation, drift, and homogenizing dispersal in fungal community assembly. 3. Results We detected 7,280 amplicon sequence variants with 5,270 associated with soil, 3,887 with roots and 1,877 found across both roots and soils. Deterministic processes dominated root and soil fungal communities at all sites except one where stochastic processes (i.e., dispersal-limitation and drift) controlled root-fungi. Despite the dominance of determinism in fungal community assembly, the proportion of processes differed by site. Assembly processes did not vary with tree age. 4.Synthesis Taken together, we suggest that the local environment, water limitation, and partner-preference between trees and their associated fungi, influence fungal community composition across the range of P. menziesii. We conclude that while fungal communities occurring near P. menziesii are dominated by homogenizing selection, the role of neutral processes still has minor influence on community assembly and may be important in shaping spatially isolated communities and those with strong gradients of fungal diversity. Brief description of collection and processing of data: Trees were cored and tree-rings measured to estimate the age of each tree. Soil and root samples were taken around P. menziesii and environmental DNA was extracted for amplification. The ITS2 region was amplified to identify fungal communities of each root and soil sample. Fungal sequences were quality filtered and rarefied to 90% of the minimum read abundance. Scientific Names Pseudotsuga menziesii Description of files (names, or if too numerous, number of files, file type(s): PSME_Tree_Fungi_data.xlsx - an excel spreadsheet with separate sheets for tree data and fungal sequence abundance. TreesSheet_PSME_Tree_Fungi_data.csv - a .csv version of a sheet with tree data SequenceSheet_PSME_Tree_Fungi_data.csv - a .csv version of a sheet with fungal sequence data MetadataSheet_PSME_Tree_Fungi_data.csv - a .csv version of a sheet with metadata information, including abbreviations Definition of acronyms, codes, and abbreviations: ASV; amplicon sequence variant DBH; Diameter at breast height (1.37m) in centimeters CEBR: Cedar Breaks National Monument JOHN: John Prince Research Forest KAML: Kamloops WELL: Wellsville Mountains National Wilderness UFDP; Utah Forest Dynamics Plot Description or definition any other unique information that would help others use your data: N/A   Descriptions of parameters/variables: a. Temporal (beginning and end dates of data collection): Data was collected in the summer of 2017 and 2018 and DNA extraction and sequencing was conducted in 2019. b. Instruments used and units of measurements: N/A c. Column headings of data files (for tabular data) ID: Site: Type: DBH: Age: PH: Elevation ASV_ID: Sequences: 00-0002R: 0001-soil-g: 1000: 1001-A: 1001R: 1012: 1012R: 1015-A: 1015R: 1023: 1032-A: 1032R: 1033: 1033R: 1043: 1046: 1046R: 1054: 1054R: 1057: 1057R-A: 1069-A: 1069KR: 1075-A: 1075R: 1080: 116: 116KR: 133-A: 133R: 16-A: 16R: 178: 178R: 183: 183KR: 211R: 212: 22-0120R: 22-1565: 22-1814: 22-1814R: 227: 227KR: 23-1565R: 23-1710: 23-1740R: 23-1755: 24-0527R: 24-0977R: 24-977: 26-0234R: 28-0239: 28-0362: 28-0362R: 30-0699: 30-0699R: 300: 300KR: 340g: 340KR: 343KR: 448: 448KR: 53: P10R: P12: P13R-A: P2R: P4R: P5R-A: P6: P6R: PME-10: PME-11: PME-2: PME-20: PME-3: PME-4: PME1: PME11R: PME12R: PME1R: PME20R: PME3R-A: PME5: Kingdom: Phylum: Class: Order: Family: Genus: Species d. Location/GIS Coverage: The sites were John Prince Research Forest (54.6° N, 124.3° W; British Columbia, Canada), Kamloops (50.8° N, 120.3° W; British Columbia, Canada), Wellsville Mountains National Wilderness (41.6° N 112.0° W; Utah, USA), and the Cedar Breaks National Monument (37.6° N, 112.8° W; Utah, USA) e. Symbol used for missing data: N/A Special software required to use data: None. Publications that cite or use this data: Birch, J. D., Lutz, J. A., Karst, J. 2022. Dancing with Douglas-fir: Determinism dominates fungal community assembly processes. Journal of Ecology. This data was not derived from another data source.