generate_point_df {ElevDistr}

Generate a data frame with points above the treeline

Description

A data frame is generated containing only points that are at or above the treeline. The calculation of the treeline (when using default thresholds) is based on Paulsen and Körner, Alp. Bot. 124: 1-12 (2014).

Usage

generate_point_df(gstRaster, gslRaster, stepSize = 0.0416666,
                        gstTreshold = 6.4, gslTreshold = 94)

Arguments

gstRaster

Climatic raster that contains the growing season temperature. Data type "SpatRaster".

gslRaster

Climatic raster that contains the growing season length. Data type "SpatRaster".

stepSize

Step size for the sampling (in degree). This defines how fare the coordinates are apart. One value, data type "numeric" and finite.

gstTreshold

Growing season temperature threshold for tree growth (in degree Celsius). One value, data type "numeric" and finite.

gslTreshold

Growing season length threshold for tree growth (days). One value, data type "integer" and finite.

Value

Data frame that contains coordinates of points above the treeline.

Author(s)

Livio Bätscher, Jurriaan M. de Vos

Examples

#Get raster layer from CHELSA
gstURL <- paste0("https://os.zhdk.cloud.switch.ch/envicloud/chelsa/chelsa_V2/",
                 "GLOBAL/climatologies/1981-2010/bio/CHELSA_gst_1981-2010_V.2.1.tif")
gslURL <- paste0("https://os.zhdk.cloud.switch.ch/envicloud/chelsa/chelsa_V2/",
                 "GLOBAL/climatologies/1981-2010/bio/CHELSA_gsl_1981-2010_V.2.1.tif")

gst <- terra::rast(gstURL, vsi = TRUE)
gsl <- terra::rast(gslURL, vsi = TRUE)

#Now generate a example data frame
temp <- generate_point_df(gstRaster = gst, gslRaster = gsl, stepSize = 10,
                         gstTreshold = 6.4, gslTreshold = 94)