DOI: 10.6084/m9.figshare.26706076.v1
title: Data and R codes for Forest temporal stability declines over stand age at multiple spatial scales.

description: Description of the data and file structureOur database contains species composition data and corresponding codes for calculating five stability components (species stability, species asynchrony, alpha stability, spatial asynchrony, and gamma stability) and three diversity components (functional alpha, beta, and gamma diversity) of 2886 plots between 1977 and 2022. Other factors include associated environmental variables such as temperature, water availability, and soil data, as well as functional trait data at species level.<b>Files and variables</b><b>File:</b> usa_cond8.csv<b>Description:</b> plot informationplot_name: plot IDplot_year: plot ID+FinYIniY: calendar year in last observationFinY: calendar year in this observationLAT: latitudeLON: longitudeIniSA: stand age in last observationFinSA: stand age in this observationMAT1: mean annual temperatureCMI1: climate moisture indexECO: ecoregion<b>File:</b> usa_tree10.csv<b>Description: </b>species composition informationplot_name: plot IDplot_year: plot ID+FinYsubplot_name: subplot IDsubplot_year: subplot ID+FinYIniY: calendar year in last observationFinY: calendar year in this observationtree_name: tree IDspecies: species namedbh: diameter at breast height in this observationBA: basal area in this observationDRYBIO_AG: aboveground biomass in this observationtree_year: tree_name+FinY<b>File:</b> soil.csv<b>Description:</b> soil data for each plot in our analysis.plot_name: plot IDnitrogen: total nitrogen (g kg-1, TOTN)soc: organic carbon content (g kg-1, SOC)cec: cation exchange capacity (cmol kg-1, CEC)phh2o: pH in H2O (pH)<b>File:</b> trait.csv<b>Description:</b> functional trait data for each species.species: species namesla: specific leaf area (SLA, mm2 mg-1)nmass: nitrogen content per leaf mass (Nmass, mg g-1)pmass: phosphorus content per leaf mass (Pmass, mg g-1)ldmc: leaf dry matter content (LDMC, mg g-1)wd: wood density (WD, g m-3)<b>File: </b>climate.csv<b>Description:</b> climate data for each plot.plot_name: plot IDYear: calendar yearpre: annual precipitationpet: annual potential evapotranspirationtemp: mean annual temperatureppt: climate moisture index; annual precipitation minus annual potential evapotranspiration<b>Code</b><b>File name:</b> extract.r<b>Description:</b> This code is used to extract plot information and species composition data for each plot from the original FIA dataset. The United States Department of Agriculture’s Forest Inventory and Analysis (FIA) program dataset is available at https://www.fia.fs.usda.gov/tools-data/.<b>File name:</b> submit.r<b>Description:</b> This code is used to calculate stability components and diversity components based on species composition and functional trait data, and to perform the analysis and draw plots in the article.All codes can be runned in R (version 4.3.1).Access informationData was derived from the following sources:the United States Department of Agriculture’s Forest Inventory and Analysis (FIA) program (https://www.fia.fs.usda.gov/tools-data/)TRY database for functional trait data (https://www.try-db.org)CRU TS database for climate data. Harris, I., Osborn, T. J., Jones, P. & Lister, D. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. <i>Sci. Data</i> <b>7</b>, 109, doi:10.1038/s41597-020-0453-3 (2020).SoilGrid database for soil data. Poggio, L.* et al.* SoilGrids 2.0: producing soil information for the globe with quantified spatial uncertainty. <i>Soil</i> <b>7</b>, 217-240, doi:10.5194/soil-7-217-2021 (2021).<br>