Study ID 473

Fourteen years of mapped permanent quadrats in a northern mixed prairie

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Realm: Terrestrial
Climate: Temperate
Biome: Temperate grasslands, savannas and shrublands
Central latitude: 46.316667
Central longitude: -105.800000
Duration: 14 years, from 1932 to 1945

2350 records

95 distinct species

Across the time series Vulpia octoflora is the most frequently occurring species


Anderson, J., Vermeire, L. & Adler, P.B. (2011) Fourteen years of mapped, permanent quadrats in a northern mixed prairie, USA. Ecology, 92, 1703-1703.


This historical data set consists of 44 permanent 1-m2 quadrats located on northern mixed prairie in Miles City, Montana, USA. Individual plants in these quadrats were identified and mapped annually from 1932 through 1945. Quadrats were located in six pastures assigned to cattle grazing treatments with light, moderate, and heavy stocking rates of 1.24, 0.92, and 0.76 ha/ animal-unit-month (two pastures in each). These data provide unique opportunities to test the interactive effects of grazing and climate variables on demographic rates, plant–plant interactions, and population and community dynamics. We provide the following data and data formats: (1) the digitized maps in shapefile format; (2) a tabular version of the entire data set (a table that replaces the full spatial data with one x,y coordinate for each individual perennial plant record); (3) grazing treatment information; (4) an inventory of the years each quadrat was sampled; (5) a species list, containing information on plant growth forms and shapefile geometry type (e.g., points or polygons); (6) a record of changes in species names; (7) daily precipitation and temperature records; and (8) counts of annual plants in the quadrats (annuals were counted, not mapped, by the original mappers).Experimental or sampling design a. Design characteristics: 44 permanent quadrats were located in 6 different pasture units. b. Permanent plots: We have not been able to relocate the original quadrats because of a lack of permanent markers. c. Data collection: Quadrats were mapped annually from 1932 to 1945, with some exceptions (see the quadrat sampling schedule data file in IV). Quadrats were mapped in the late spring-early summer growing season each year (generally between late May and July). Research Methods a. Field / laboratory: The data were collected in the field using pantographs (Hill 1920), a mechanical device used to make scale drawings. The original paper maps were first scanned and then stored as TIFF image files. These images were then converted into shapefiles by heads-up digitization in ArcGIS. For a complete digitization protocol, contact Peter Adler. Daily climate data were obtained from the Miles City airport, Wiley Field (800 m a.s.l., 46°26’N, 105°53’W) located 9 km north of the study site. For the period beginning in 1933, these data are available on-line from the National Climate Data Center at b. Instrumentation: Pantographs, scanners, and computers running ArcGIS, Python, and R. c. Taxonomy and systematics: Originally assigned plant names were corrected for synonyms based on the USDA Plants Database ( We recorded these name changes in the species_name_changes.csv file. d. Permit history: N/A e. Legal/organizational requirements: N/A Unit of abundance = IndCountInt, Unit of biomass = NA