calc_C4_ratio: Predict C4 Ratio for Grasses

In rebeccalpowell/grassmapr: Predict C3/C4 Grass Distribution

Description

Calculates the proportion of grasses with C4 photosynthetic pathway based on climate data (and, optionally, vegetation "greenness" weights). Output layer represents the C4 proportion of grasses in each grid cell, based on ratio of C4-favorable months to growing-season months.

Usage

calc_C4_ratio(C4.mask, GS.mask, veg.index = NULL, filename = "", ...)

Arguments

C4.mask	Raster* object. Each layer represents C4 climate mask for given temporal window, may be result of intersect_masks. Must have same number of layers as GS.mask.
GS.mask	Raster* object. Each layer represents growing season climate mask for given temporal window, may be result of intersect_masks. Must have same number of layers as C4.mask.
veg.index	Raster* object. Optional layers to weight C4 grass proportion based on vegetation "greenness" metric (e.g., a vegetation index). Must match temporal window and number of layers as C4.mask and GS.mask.
filename	Character. Optional output root filename passed to writeRaster, default output file type is GeoTiff. If not specified, output is written to a temporary file.
...	Other arguments passed to writeRaster.

Value

Raster layer. Proportion of grasses with C4 photosynthetic pathway.

See Also

intersect_masks, count_months, overlay.

Examples

# Calculate C4 ratio for North America, based on climate data only

# C4 and Growing Season (GS) climate masks are results of mask_climate()
C4_ratio <- calc_C4_ratio(C4_mask, GS_mask)

# Calculate C4 ratio, based on climate and monthly vegetation greenness

# Load monthly vegetation index for North America
data(ndvi_NA)
C4_ratio_vi <- calc_C4_ratio(C4_mask, GS_mask, veg.index = ndvi_NA)

# Plot climate-based C4 vegetation ratio
plot(C4_ratio)

rebeccalpowell/grassmapr documentation built on June 20, 2019, 8:07 p.m.