AppraisingGrazing

This repository contains data and code relating to the study:

Herbivore effects on plant quality and quantity in a shortgrass prairie

Authors:

Rehb, J. & E.A.R. Welti

Study investigation of:

bison, cattle, prairie dog, and insecticide effects on plant biomass and plant and soil chemistry in an eastern Montana shortgrass prairie during the summer of 2022

rawdata file:

AP_propertySizes_grazeDens.csv :

• Contains project data including Metadata on site properties and grazer densities

ClipBiomass.csv :

• Contains data on g/m^2 dry biomass of grasses, forbs, and woody plants

PastureMeter.csv :

• Contains data on pasture meter measurements and conversions to g/m^2 dry plant biomass

PastureMeterCalibration.xlsx :

• Contains regression equation calculation to convert pasture meter measurements into units of dry plant biomass

PD_PooCount.csv :

• Contains data on counts of prairie dog dungs/m^2

PlantChem.csv :

• Contains data on chemistry of plant (grass, forb, woody when available) including %C, %N, ppm Al, ppm B, ppm Ca, ppm Cu, ppm Fe, ppm K, ppm Li, ppm Mg, ppm Mn, ppm Na, ppm Ni, ppm P, ppm Pb, ppm S, ppm Si, ppm Sr, ppm Ti, ppm V, & ppm Zn

Rainfall.csv :

• Contains data on rainfall in mm collected across the growing season in a local rain gauge

RingCounts.csv :

• Contains data on counts of grasshoppers per grasshopper ring (/0.2m^2)

SiteCorners.csv :

• Contains data on latitude and longitude of site boundaries

SoilChem.csv :

• Contains data on site soil elemental chemistry including %C, %N, ppm Al, ppm Ca, ppm Co, ppm Fe, ppm K, ppm Mg, ppm Mn, ppm Na, ppm P, ppm S, & ppm Zn

stocking.csv :

• Contains data on bison and cattle stock rates, and presence of prairie dogs and insecticide use per site

outputs file:

ElementalResponses_grazingGradient.csv :

• statistical results for responses of plant and soil chemistry responses to herbivore densities and month

ElementalResponses_grazingTrt.csv :

• statistical results for responses of plant and soil chemistry responses to herbivore regime and month

ForbNutrients_ResponsesToMonth_WithinSites.csv :

• statistical results for responses of forb chemistry responses to month

GrassNutrients_ResponsesToMonth_WithinSites.csv :

• statistical results for responses of grass chemistry responses to month

SiteMonthLevel.csv :

• all data from raw data folder summarized at the level of each site and month; created by R/calculate_estimates.R

SoilNutrients_ResponsesToMonth_WithinSites.csv :

• statistical results for responses of grass chemistry responses to month

SupplementalTables.xlsx :

• statistical results including all paper's Supplemental Tables for models testing herbivore effects on plant quality, quantity, and soil elemental chemistry

R file:

calculate_estimates.R :

• R script containing code to summarize data from the rawdata folder into a combined file with all data provided as one value for each site and month. The result of running this script is provided in outputs/SiteMonthLevel.csv

DriverModels_H1_lmm_GrazingGradient.R :

• R script containing code for models examining effects of herbivore densities to test H1: Grazing will increase plant quality with smaller herbivores having larger effects

DriverModels_H1_lmm_GrazingTrt.R :

• R script containing code for models examining effects of herbivore regimes to test H1: Grazing will increase plant quality with smaller herbivores having larger effects

DriverModels_H2_GrazingGradient.R :

• R script containing code for models examining effects of herbivore densities to test H2: All grazers will decrease aboveground plant biomass, and insect herbivory will equal that of large grazer herbivory

DriverModels_H2_GrazingTrt.R :

• R script containing code for models examining effects of herbivore regimes to test H2: All grazers will decrease aboveground plant biomass, and insect herbivory will equal that of large grazer herbivory

DriverModels_H3_abovegroundbiomass.R :

• R script containing code for models to test plant biomass component of H3: Plant nutrient content will be greatest in the early season while biomass will peak mid-season

DriverModels_H3_nutrients.R :

• R script containing code for models to test plant nutrient component of H3: Plant nutrient content will be greatest in the early season while biomass will peak mid-season

GhopRings.R :

• R script containing code to summarize data of grasshopper densities from ring counts and examine their variation over grazing regimes

PDtown_ttests.R :

• R script containing code to conduct t tests to examine prairie dog effects on soil within properties as a robustness analysis

plots file:

ForbChem_individualPlots.tif :

• main results figure (Fig. 2) showing responses of forb concentrations of %N, ppm P, ppm K, ppm Mg, ppm Na, and ppm Si to different grazing regimes and over the four sampling months (June-September)

ForbChem_plots.R :

• R script to make the figure ForbChem_individualPlots.tif

GrassChem_individualPlots.tif :

• main results figure (Fig. 1) showing responses of grass concentrations of %N, ppm P, ppm K, ppm Mg, ppm Na, and ppm Si to different grazing regimes and over the four sampling months (June-September)

GrassChem_plots.R :

• R script to make the figure GrassChem_individualPlots.tif

PastureMeter.tif :

• main results figure (Fig. 4) showing responses of aboveground plant biomass to different grazing regimes and over the four sampling months (June-September)

PastureMeterEsts_Plot.R :

• R script to make the figure PastureMeter.tif

sites2022_Rebh.tiff :

• site map

SoilChem_individualPlots.tif :

• main results figure (Fig. 4) showing responses of soil concentrations of %C, %N, ppm P, ppm K, ppm Mg, and ppm Na to different grazing regimes and over the four sampling months (June-September)

SoilChem_plots.R :

• R script to make the figure SoilChem_individualPlots.tif