Read natural-grass productivity from an LPJmL run. — read_lpjml_grass

Sums the natural-grass PFT net primary production bands (the ungrazed natural stand, climate-driven) into a per-cell productivity layer used to distribute grazing livestock by grass production rather than pasture area. The pinned WHEP artifact is used by default; pass run_dir to read a local finished LPJmL run, or pass productivity / productivity_path to use an already-derived custom artifact. Natural-grass NPP is exogenous to the grazing density, so it avoids the livestock to grassland_lsuha to grass-NPP circularity.

Usage

read_lpjml_grass_productivity(
  run_dir = NULL,
  years = NULL,
  first_year = 1901L,
  example = FALSE,
  productivity = NULL,
  productivity_path = NULL
)

Arguments

run_dir: Path to the LPJmL run output directory holding pft_npp.nc. If unset, the pinned lpjml-grass-productivity artifact is used.
years: Integer vector of calendar years to read.
first_year: First calendar year of the run's output time axis.
example: If TRUE, return a small fixture instead of reading a run.
productivity: Optional already-derived natural-grass productivity tibble/data frame. Takes precedence over pinned data and run_dir.
productivity_path: Optional path to an already-derived natural-grass productivity artifact (.parquet, .csv, or .rds). Takes precedence over pinned data and run_dir.

Value

A tibble with lon, lat, year and grass_npp (gC/m2/yr).

Examples

read_lpjml_grass_productivity(example = TRUE)
#> # A tibble: 3 × 4
#>      lon    lat  year grass_npp
#>    <dbl>  <dbl> <int>     <dbl>
#> 1   9.25  47.8   2000      413.
#> 2  35.8   -1.25  2000      631.
#> 3 -55.2  -12.2   2000      349.