Cover and density data of southwestern ponderosa pine understory plants in permanent chart quadrats (2002-2020+)

This data publication includes cover and density data collected on 101 permanent 1 meter (m) x 1 m (1-m²) quadrats located within southwestern ponderosa pine ecosystems near Flagstaff, Arizona, USA. Individual plants in these quadrats were identified and mapped annually for 21 years (2002-2022), and we plan to add data as we continue to survey these quadrats in the future. The original chart quadrats were established between 1912 and 1927. We provide the following data and data formats: (1) digitized maps of all plant locations in shapefile and geodatabase format, (2) shapefiles showing annual locations of each individual plant species, (3) exported annual maps of each quadrat in TIFF and PDF format, (4) annual basal area of each species per quadrat for species mapped as polygons, (5) tabular representation of polygon areas and centroid locations for plant species mapped as polygons, (6) tabular representation of point locations for plant species mapped as points, (7) plot-scale 20 m x 20 m overstory tree canopy cover, tree basal area, parent material, and elevation, (8) quadrat-scale information (e.g., quadrat site and number, coordinates in UTM Zone 12 and latitude/longitude, and descriptive comments for each quadrat), (9) plant species list, (10) summary of plant species observed in each quadrat, (11) summary of quadrats mapped by site and year, and (12) data formatted for use in Integral Projection Models (IPM) and plant population analyses.
The original chart quadrats were established to determine the effects of domestic livestock grazing on herbaceous plants and pine seedlings. Today these data provide opportunities to examine the effects of climate and land-use change on plant demography, population dynamics, and community processes.
For more information about this study and these data see Moore et al. (2022, https://doi.org/10.1002/ecy.3661). All associated novel code files are permanently archived in a Zenodo repository (https://doi.org/10.5281/zenodo.7581946). These data were originally published on 11/18/2021. On 03/30/2022 data for 2021 were added to this package and minor metadata updates were made. New data include all surveys conducted in 2021, a repair for Fry Park Quadrat 30739 in which it was incorrectly rotated in 2018, 2019 and 2020, and new single-species shapefiles for 2021. We added a recently-discovered 2011 survey record for Wild Bill Quadrat 114. We have also resymbolized plant distributions, and expanded some comments, in all the quadrat map TIFF images and the associated PDF map compilation. On 02/16/2023, data for 2022 were added to this package and five previous data-entry errors were found and fixed. Specifically, on Plot 30719 [2019] we fixed the location of one observation of Gutierrezia sarothrae. On Plot 30739 [2019] plants misidentified as Elymus elymoides were corrected to Eremogone fendleri. On Plot 107 [2019] we fixed the location of one observation of Pinus ponderosa. On Plot 119 [2019] plants misidentified as Poa fendleriana were corrected to Festuca arizonica. On Plot 125 [2020] plants misidentified as Antennaria parvifolia were corrected to Antennaria rosulata. We have also resymbolized plant distributions in all the quadrat map TIFF images and the associated PDF map compilation.