DOI: 10.5061/dryad.6djh9w1f4
title: Grassland aboveground biomass, composition, and chemistry from multiple sites and years in Yellowstone National Park

description: This data set includes measurements of aboveground plant biomass (gm-2),
 percent live and dead, composition (percent graminoid [grasses, sedges,
 rushes] and non-graminoid [other monocots, dicots], and carbon and
 nitrogen content (ppm) of aboveground biomass collected during three
 studies (1988 & 1989; 1999-2001; 2012-2014) at grasslands grazed
 by herds of elk (Cervus canadensis), bison (Bison bison), and pronghorn
 (Antilocapra americana) in Yellowstone National Park. A total of 25
 different grasslands were sampled during the studies. At each grassland,
 measurements were made outside and inside small (1.5 x 1.5 m) temporary
 exclosures moved approximately monthly throughout each growing season to
 determine ungulate consumption and aboveground production. Plant data were
 also gathered at a subsample of 13 of the grasslands inside permanent
 exclosures erected during the summer before each study. Monthly
 aboveground plant P content (ppm) is also provided at six sites in 2013
 and 2014. Location (latitude, longitude), elevation, and 0 – 10 cm total
 soil C and N are included for all the sites.
description: # Grassland aboveground biomass, composition, and chemistry from multiple
 sites and years in Yellowstone National Park Dataset DOI:
 [10.5061/dryad.6djh9w1f4](10.5061/dryad.6djh9w1f4) ## Description of the
 data and file structure This data set includes plant and soil data
 collected to understand the role of herds of migratory ungulates and soil
 conditions in controlling grassland production in Yellowstone National
 Park. The data span three separate studies: 1988 & 1989, 1999 - 2001,
 and 2012 - 2014.  Plant biomass, percent live and dead biomass,
 graminoid/non-graminoid abundance, and plant chemistry data are nested by
 site and year. At each site, plant data were collected in replicated (n=
 8-12) 0.50 x 0.50 cm quadrats in grazed grassland and in the center 0.50 x
 0.50 cm of temporary exclosures (1.5 x 1.5 m) (n = 4 - 6) moved
 approximately every four weeks during each growing season. At 13 of the
 study sites, plant data were also collected inside 8 x 8 m, 10 x 10 m, or
 15 x 15 m “permanent” exclosures erected the summer before sampling and
 left in place throughout each study.  During the 1999 -2001 and 2012 –
 2014 studies, plant sampling at each site occurred inside the permanent
 exclosure(s) (ungrazed grassland) usually on the same day and occasionally
 within three days as in the grazed grassland.  During the 1988 and 1989
 study, plant data were collected inside permanent exclosures only at peak
 biomass.  Soil samples from which carbon and nitrogen were determined were
 sampled only once in the first year of each of the studies.  Carbon and
 nitrogen were determined on a sample pooled from three to seven random
 0-10 cm soil samples collected in grazed grassland at each site at the
 beginning of the studies.             Note that the frequency and/or
 spatial extent of sampling plant biomass (ie, total biomass, live vs dead
 biomass, graminoid vs nongraminoid biomass), plant chemistry (nitrogen and
 phosphorus), and soil chemistry (carbon and nitrogen) differed.  Plant
 biomass was sampled in grazed grassland and inside temporary and permanent
 exlcosures at replicated locations at multiple timepoints at each
 grassland site in each year.  The pooled plant tissue collected at a site
 provided single measure (ppm) of plant nitrogen and phosphorus for a site
 at each time point plant chemistry was determined.  Soil chemistry was
 determined once at each site, providing single measures of soil carbon and
 nitrogen for each of the sites during each study.  Empty cells in the data
 file reflect missing data. ### Files and variables #### File: Data_S1.zip
 **Description:** * siteid:  Unique identifier for each site. *
 lat: Latitude location of site (decimal degrees). * long: Longitude
 location of site (decimal degrees). * elev: Elevation of site (meters). *
 year: Year that sample was collected. * trt: Five codes: *gr*, *te*,  *pe,
 sgr, and ste*. g*r* refers to samples collected in grazed grasslands; *te*
 refers to samples taken inside temporary exclosures in grasslands, and
 *pe* refers to those taken inside permanent exclosures in grasslands. 
 *ste* refers to samples of herbaceous vegetation growing under individuals
 of sagebrush (*Artemisia tridentata) *that had been fenced from grazing
 with temporary exclosures and *sgr* refers to samples collected under
 individuals of sagebrush that had not been protected from grazing.
 Sagebrush occurred at only two sites, lsg and usg. *
 sampleinterval.plt: The sequential intervals during which plants at grazed
 grassland and shrub-grassland (*gr*, *te, sgr, ste*) were sampled during
 each year.  During these intervals, ungrazed grassland (*pe*) was sampled
 mostly on the same day that grazed grassland at a site was sampled.  Refer
 to “dayofyear.plt” to determine the date that plant samples were
 collected. * quadrat#: The identifying quadrat number. * dayofyear.plt:
 The day of year that plant biomass was sampled. * totshtbiom: Shoot
 biomass (g/m^2) estimated nondestructively with canopy intercept method. *
 live.percent: Percent of total biomass that was live (green); estimated as
 the percent of pin contacts with green tissue. * dead.percent: Percent of
 total biomass that was dead (tan, red or brown); estimated as the percent
 of pin contacts with dead tissue. * gram.percent: Percent of total biomass
 that was graminoid (grass, sedge, and rush) biomass.  Calculated as the
 percent of pin contacts on graminoid tissue. * forb.percent: Percent of
 total biomass that was non-graminoid biomass.  Calculated as the percent
 of pin contacts on non-graminoid tissue. * shrub.percent: Percent of total
 biomass that was shrub biomass.  Calculated as the percent of pin contacts
 on shrub tissue. * dayofyear.np: Day of year that plant tissue samples
 were collected for N and P analyses. * lfnppm: Shoot nitrogen
 concentration (ppm). * lfpppm: Shoot phosphorus concentration (ppm). *
 soilcppm: Total 0 - 10 cm soil carbon (ppm). * soilnppm: Total 0 - 10 cm
 soil nitrogen (ppm).