DOI: 10.5061/dryad.2547d7x2n
title: Site-specific biogeochemical response to livestock grazing and climate change differs across four continents

description: Drylands make up 40% of terrestrial ecosystems and hold up to 20% of the
 global soil organic carbon pool. Most semi-arid drylands are, to some
 extent, grazed by livestock. However, the impact of livestock grazing on
 carbon cycle dynamics over large spatial and temporal scales remains
 uncertain, especially as the effects of climate change become more
 pronounced. Thus far, there has been little work, which has explored how
 site-specific land management may interact with localized shifts in
 climate to affect biogeochemical processes in dryland ecosystems globally,
 particularly in the tropics. We explored, using simulation modeling, how
 grazing intensity and projected climate change may impact biogeochemical
 dynamics in dryland regions in North America, South America, Asia, and
 Africa. Our simulation results showed a site-specific biogeochemical
 response to livestock grazing and climate change, even across ecologically
 similar dryland systems. In sites that had smaller projected shifts in
 climate (i.e., North and South America), heavy grazing decreased soil
 carbon inputs, outputs, and storage. In the other two sites, particularly
 in the African site, shifts in climate had the largest impact on simulated
 biogeochemical processes, with a projected 20% decrease in the soil
 organic carbon pool in the African site by the end of the century. Our
 study highlights the importance of considering how localized shifts in
 climate may affect dryland ecosystem function as this may overwhelm land
 management effects over longer time scales. Our work also suggests that
 more research is needed to better understand how small-scale,
 site-specific sensitivity to climate change and land use may influence
 dryland carbon cycle dynamics at the global scale, particularly in
 tropical regions.
description: Simulation model files for DAYCENT for four dryland sites located
 in North America, South America, Asia, and Africa. Files in ‘Initial Model
 Runs’ used observed data for the model to reach equilibrium and are the
 base input files used for further simulations. Files in ‘Simulation Runs’
 were the simulations through the end of the century, altering grazing
 intensity and SSP scenario. Climate data (precipitation and temperature
 datasheets) were compiled using observed historical data from nearby
 weather stations and downscaled CMIP6 climate data for three SSP scenarios
 provided by Predictia Solutions. Simulated soil organic carbon and
 nitrogen, net primary productivity, and greenhouse gas fluxes are model
 output from DAYCENT.
description: # Site-specific biogeochemical responses to livestock grazing and climate
 change Simulation model files for DAYCENT for four dryland sites located
 in North America, South America, Asia, and Africa. Files in Initial Model
 Runs used observed data for the model to reach equilibrium and are the
 base input files used for further simulations. Files in Simulation Runs
 were the simulations through the end of the century, altering grazing
 intensity and SSP scenario. Climate data (precipitation and temperature
 datasheets) were compiled using observed historical data from nearby
 weather stations and downscaled CMIP6 climate data for three SSP scenarios
 provided by Predictia Solutions. Simulated soil organic carbon and
 nitrogen, net primary productivity, and greenhouse gas fluxes are model
 output from DAYCENT. ## Description of the data and file structure
 africaprcp.csv -ssp: shared socio-economic pathway representing downscaled
 output from 3 climate models from CMIP6 (observed, 1-2.6, 2-4.5, 5-8.5)
 -yr: year (1950 - 2100) -dayofyr: day of year (1-365/366) -prcp:
 precipitation (centimeters) africatemp.csv -ssp: shared socio-economic
 pathway representing downscaled output from 3 climate models from CMIP6
 (observed, 1-2.6, 2-4.5, 5-8.5) -yr: year (1950-2100) -dayofyr: day of
 year (1-365/366) -tmax: maximum daily temperature (degrees celsius) -tmin:
 minimum daily temperature (degrees celsius) asiaprcp.csv -ssp: shared
 socio-economic pathway representing downscaled output from 3 climate
 models from CMIP6 (observed, 1-2.6, 2-4.5, 5-8.5) -yr: year (1950 - 2100)
 -dayofyr: day of year (1-365/366) -prcp: precipitation (centimeters)
 asiatemp.csv -ssp: shared socio-economic pathway representing downscaled
 output from 3 climate models from CMIP6 (observed, 1-2.6, 2-4.5, 5-8.5)
 -yr: year (1950-2100) -dayofyr: day of year (1-365/366) -tmax: maximum
 daily temperature (degrees celsius) -tmin: minimum daily temperature
 (degrees celsius) cn.csv: -time: year (1, 1901 - 2100) -site: site name
 (Shortgrass Steppe is North America, Pilcaniyeu is South America, Inner
 Mongolia is Asia, and Mpala is Africa) -graz: grazing intensity (heavy,
 moderate, or light) -ssp: shared socio-economic pathway representing
 downscaled output from 3 climate models from CMIP6 (1-2.6, 2-4.5, 5-8.5)
 -soc: simulated total soil organic carbon to 20 centimeters depth (grams
 carbon meter-2) -fast_c: simulated fast soil organic carbon fraction to 20
 centimeters depth (grams carbon meter-2) -int_c: simulated intermediate
 soil organic carbon fraction to 20 centimeters depth (grams carbon
 meter-2) -slow_c: simulated slow soil organic carbon fraction to 20
 centimeters depth (grams carbon meter-2) -son: simulated total soil
 organic nitrogen to 20 centimeters depth (grams nitrogen meter-2) -fast_n:
 simulated fast soil organic nitrogen fraction to 20 centimeters depth
 (grams nitrogen meter-2) -int_n: simulated intermediate soil organic
 nitrogen fraction to 20 centimeters depth (grams nitrogen meter-2)
 -slow_n: simulated slow soil organic nitrogen fraction to 20 centimeters
 depth (grams nitrogen meter-2) flux.csv: -site: site name (Shortgrass
 Steppe is North America, Pilcaniyeu is South America, Inner Mongolia is
 Asia, and Mpala is Africa) -ssp: shared socio-economic pathway
 representing downscaled output from 3 climate models from CMIP6 (1-2.6,
 2-4.5, 5-8.5) -graz: grazing intensity (heavy, moderate, or light) -time:
 year (1901 - 2100) -co2ann: annual heterotrophic carbon dioxide
 respiration flux (grams carbon hectare-1 year-1) -ch4ann: annual methane
 oxidation flux (grams carbon hectare-1 year-1) -n2oann: annual nitrous
 oxide flux (grams nitrogen hectare-1 year-1) naprcp.csv: -ssp: shared
 socio-economic pathway representing downscaled output from 3 climate
 models from CMIP6 (observed, 1-2.6, 2-4.5, 5-8.5) -yr: year (1950 - 2100)
 -dayofyr: day of year (1-365/366) -prcp: precipitation (centimeters)
 natemp.csv: -ssp: shared socio-economic pathway representing downscaled
 output from 3 climate models from CMIP6 (observed, 1-2.6, 2-4.5, 5-8.5)
 -yr: year (1950-2100) -dayofyr: day of year (1-365/366) -tmax: maximum
 daily temperature (degrees celsius) -tmin: minimum daily temperature
 (degrees celsius) npp.csv: -time: year and month (1 - 1911, 1912.xx -
 2100.xx; each decimal increment represents a month of the year starting
 with .00 which represents January) -site: site name (Shortgrass Steppe is
 North America, Pilcaniyeu is South America, Inner Mongolia is Asia, and
 Mpala is Africa) -graz: grazing intensity (heavy, moderate, or light)
 -ssp: shared socio-economic pathway representing downscaled output from 3
 climate models from CMIP6 (1-2.6, 2-4.5, 5-8.5) -agcacc: growing season
 accumulator for aboveground carbon production (grams carbon meter-2
 year-1) \ -bgjcacc: growing season accumulator for juvenile fine root
 carbon production (grams carbon meter-2 year-1)\ -bgmcacc: growing season
 accumulator for mature fine root carbon production (grams carbon meter-2
 year-1) \ saprcp.csv: -ssp: shared socio-economic pathway representing
 downscaled output from 3 climate models from CMIP6 (observed, 1-2.6,
 2-4.5, 5-8.5) -yr: year (1950 - 2100) -dayofyr: day of year (1-365/366)
 -prcp: precipitation (centimeters) satemp.csv: -ssp: shared socio-economic
 pathway representing downscaled output from 3 climate models from CMIP6
 (observed, 1-2.6, 2-4.5, 5-8.5) -yr: year (1950-2100) -dayofyr: day of
 year (1-365/366) -tmax: maximum daily temperature (degrees celsius) -tmin:
 minimum daily temperature (degrees celsius) soc.csv: -site: site name
 (Shortgrass Steppe is North America, Pilcaniyeu is South America, Inner
 Mongolia is Asia, and Mpala is Africa) -graz: grazing intensity (heavy,
 moderate, or light) -ssp: shared socio-economic pathway representing
 downscaled output from 3 climate models from CMIP6 (1-2.6, 2-4.5, 5-8.5)
 -soc_1901: simulated total soil organic carbon to 20 centimeters depth in
 1901 (grams carbon meter-2) -fast_1901: simulated fast soil organic carbon
 fraction to 20 centimeters depth in 1901 (grams carbon meter-2) -int_1901:
 simulated intermediate soil organic carbon fraction to 20 centimeters
 depth in 1901 (grams carbon meter-2) -slow_1901: simulated slow soil
 organic carbon fraction to 20 centimeters depth in 1901 (grams carbon
 meter-2) -soc_1951: simulated total soil organic carbon to 20 centimeters
 depth in 1951 (grams carbon meter-2) -fast_1951: simulated fast soil
 organic carbon fraction to 20 centimeters depth in 1951 (grams carbon
 meter-2) -int_1951: simulated intermediate soil organic carbon fraction to
 20 centimeters depth in 1951 (grams carbon meter-2) -slow_1951: simulated
 slow soil organic carbon fraction to 20 centimeters depth in 1951 (grams
 carbon meter-2) -soc_2000: simulated total soil organic carbon to 20
 centimeters depth in 2000 (grams carbon meter-2) -fast_2000: simulated
 fast soil organic carbon fraction to 20 centimeters depth in 2000 (grams
 carbon meter-2) -int_2000: simulated intermediate soil organic carbon
 fraction to 20 centimeters depth in 2000 (grams carbon meter-2)
 -slow_2000: simulated slow soil organic carbon fraction to 20 centimeters
 depth in 2000 (grams carbon meter-2) -soc_2050: simulated total soil
 organic carbon to 20 centimeters depth in 2050 (grams carbon meter-2)
 -fast_2050: simulated fast soil organic carbon fraction to 20 centimeters
 depth in 2050 (grams carbon meter-2) -int_2050: simulated intermediate
 soil organic carbon fraction to 20 centimeters depth in 2050 (grams carbon
 meter-2) -slow_2050: simulated slow soil organic carbon fraction to 20
 centimeters depth in 2050 (grams carbon meter-2) -soc_2100: simulated
 total soil organic carbon to 20 centimeters depth in 2100 (grams carbon
 meter-2) -fast_2100: simulated fast soil organic carbon fraction to 20
 centimeters depth in 2100 (grams carbon meter-2) -int_2100: simulated
 intermediate soil organic carbon fraction to 20 centimeters depth in 2100
 (grams carbon meter-2) -slow_2100: simulated slow soil organic carbon
 fraction to 20 centimeters depth in 2100 (grams carbon meter-2) -dsoc_200:
 change in simulated total soil organic carbon from 1901-2100 (grams carbon
 meter-2) -dfast_200: change in simulated fast soil organic carbon fraction
 from 1901-2100 (grams carbon meter-2) -dint_200: change in simulated
 intermediate soil organic carbon fraction from 1901-2100 (grams carbon
 meter-2) -dslow_200: change in simulated slow soil organic carbon fraction
 from 1901-2100 (grams carbon meter-2) -dsoc_150: change in simulated total
 soil organic carbon from 1951-2100 (grams carbon meter-2) -dfast_150:
 change in simulated fast soil organic carbon fraction from 1951-2100
 (grams carbon meter-2) -dint_150: change in simulated intermediate soil
 organic carbon fraction from 1951-2100 (grams carbon meter-2) -dslow_150:
 change in simulated slow soil organic carbon fraction from 1951-2100
 (grams carbon meter-2) -dsoc_100: change in simulated total soil organic
 carbon from 2000-2100 (grams carbon meter-2) -dfast_100: change in
 simulated fast soil organic carbon fraction from 2000-2100 (grams carbon
 meter-2) -dint_100: change in simulated intermediate soil organic carbon
 fraction from 2000-2100 (grams carbon meter-2) -dslow_100: change in
 simulated slow soil organic carbon fraction from 2000-2100 (grams carbon
 meter-2) -dsoc_50: change in simulated total soil organic carbon from
 2050-2100 (grams carbon meter-2) -dfast_50: change in simulated fast soil
 organic carbon fraction from 2050-2100 (grams carbon meter-2) -dint_50:
 change in simulated intermediate soil organic carbon fraction from
 2050-2100 (grams carbon meter-2) -dslow_50: change in simulated slow soil
 organic carbon fraction from 2050-2100 (grams carbon meter-2)
 Initial_Model_Runs.zip: Site Name (Africa, Asia, North America, South
 America) Initial: -crop.100: input file to parameterize vegetation
 dynamics within the model. Specific descriptions of each parameter can be
 found in crop.def. -crop.def: File used to describe the measurement and
 units for a given parameter within crop.100. -cult.100: input file to
 parameterize the effect of a cultivation event within the model. Specific
 descriptions of each parameter can be found in cult.def -cult.def: File
 used to describe the measurement and units for a given parameter within
 cult.100. -fix.100: input file of fixed parameters that control core pool
 and flow rates within the model. Specific descriptions of each parameter
 can be found in fix.def. -fix.def: File used to describe the measurement
 and units for a given parameter within fix.100. -graz.100: input file to
 parameterize the effect of a grazing event within the model. Specific
 descriptions of each parameter can be found in graz.def. -graz.def: File
 used to describe the measurement and units for a given parameter within
 graz.100. -site.100 (i.e., sgs.100 for North America, pilc.100 for South
 America, im.100 for Asia, mpala.100 for Africa): input file of
 site-specific characteristics and initial pool amounts within the model.
 Name before the .100 refers to the site name for each continent. Specific
 descriptions of each parameter can be found in site.def. -site.def: File
 used to describe the measurement and units for a given parameter within
 site.100. -site.sch (i.e., sgs.sch for North America, pilc.sch for South
 America, im.sch for Asia, and mpala.sch for Africa): input file used to
 establish simulation time and schedule events to occur during the
 simulation. Name before the .sch refers to the site name for each
 continent. -site.wth (i.e., sgs.wth for North America, pilc.wth for South
 America, im.wth for Asia, mpala.wth for Africa): input file of daily
 precipitation, minimum temperature, and maximum temperature. Name before
 the .wth refers to the site name for each continent. -outfiles.in: input
 file that lists which .out and .csv output files to generate from the
 simulation. 1 generates the file, 0 does not. -outvars.txt: input file
 that lists specific output variables to generate from simulation.
 -sitepar.in: input file of DAYCENT specific parameters to adjust using
 site-specific characteristics. -soils.in: input file to parameterize soil
 mineralogic and hydrologic characteristics within the model. -tree.100:
 input file to parameterize tree characteristics if present at site.
 Simulation_Runs.zip: Site Name (Africa, Asia, North America, South
 America) 1. grazingintensityssp: Name of folder represents the simulated
 grazing intensity (hg: heavy grazing, mg: moderate grazing, lg: light
 grazing) and shared socio-economic pathway scenario (126: SSP1-2.6, 245:
 SSP2-4.5, 585: SSP5-8.5) 2. grazingintensityssprep: Name of folder
 represents the simulated grazing intensity (HG: heavy grazing, MG:
 moderate grazing, LG: light grazing) and shared socio-economic pathway
 scenario (2.6: SSP1-2.6, 4.5: SSP2-4.5, 8.5: SSP5-8.5) and global
 circulation model used for weather simulation (1,2,3) -crop.100: input
 file to parameterize vegetation dynamics within the model. Specific
 descriptions of each parameter can be found in crop.def. -crop.def: File
 used to describe the measurement and units for a given parameter within
 crop.100. -cult.100: input file to parameterize the effect of a
 cultivation event within the model. Specific descriptions of each
 parameter can be found in cult.def. -cult.def: File used to describe the
 measurement and units for a given parameter within cult.100 -fix.100:
 input file of fixed parameters that control core pool and flow rates
 within the model. Specific descriptions of each parameter can be found in
 fix.def. -fix.def: File used to describe the measurement and units for a
 given parameter within fix.100. -graz.100: input file to parameterize the
 effect of a grazing event within the model. Specific descriptions of each
 parameter can be found in graz.def. -graz.def: File used to describe the
 measurement and units for a given parameter within graz.100. -site.100
 (i.e., sgs.100 for North America, pilc.100 for South America, im.100 for
 Asia, mpala.100 for Africa): input file of site-specific characteristics
 and initial pool amounts within the model. Specific descriptions of each
 parameter can be found in site.def. Name before the .100 refers to the
 site name for each continent. -site.def: File used to describe the
 measurement and units for a given parameter within site.100. -site.sch
 (i.e., sgs.sch for North America, pilc.sch for South America, im.sch for
 Asia, mpala.sch for Africa): input file used to establish simulation time
 and schedule events to occur during the simulation. Name before the .sch
 refers to the site name for each continent. -site.wth (i.e., sgs.wth for
 North America, pilc.wth for South America, im.wth for Asia, mpala.wth for
 Africa): input file of daily precipitation, minimum temperature, and
 maximum temperature. Name before the .wth refers to the site name for each
 continent. -sitessp.wth (e.g., sgs2.61.wth for North America SSP1-2.6, GCM
 1, pilc2.61.wth for South America SSP1-2.6, GCM 1, im2.61.wth for Asia
 SSP1-2.6, GCM 1, mpala2.61.wth for Africa SSP1-2.6, GCM 1): input file of
 projected daily precipitation, minimum temperature, and maximum
 temperature for a given shared socioeconomic pathway scenario. Naming
 scheme (before. wth) represents name of the site on a given continent, SSP
 scenario (2.6 for 1-2.6, 4.5 for 2-4.5, and 8.5 for 5-8.5), and GCM (1, 2,
 or 3). -outfiles.in: input file that lists which .out and .csv output
 files to generate from the simulation. 1 generates the file, 0 does not. \
 -outvars.txt: input file that lists specific output variables to generate
 from simulation. -sitepar.in: input file of DAYCENT specific parameters to
 adjust using site-specific characteristics. -soils.in: input file to
 parameterize soil mineralogic and hydrologic characteristics within the
 model. -tree.100: input file to parameterize tree characteristics if
 present at site. ## Code/Software daycentfigsandtables.R: * used to make
 the primary tables and figures for the manuscript and appendix figures\ *
 Completed in R (version 4.4.2) * Packages: 'ggplot2',
 'wesanderson', 'stringr', 'zoo',
 'tidyverse', 'scales', 'ggpubr',
 'cowplot', 'gt', 'climatol',
 'TRAMPR', 'lubridate'