enerscape {enerscape}R Documentation

Compute the energy landscape

Description

This is the main function to compute energy landscapes from a digital elevation model and body mass of animals based on the model from Pontzer (2016). The core of the computations are done using the gdistance (Etten, 2017) package.

Usage

enerscape(dem, m, unit = "joule", neigh = 16, method = "ARC", v = NULL)

Arguments

dem

raster file of the digital elevation model, either a raster or a full path location of the file.

m

species body mass (kg).

unit

if joules ('joule') or kilocalories ('kcal').

neigh

number of neighbor cells that are connected together.

method

method to use to compute the energy costs. 'ARC' refers to the model from Pontzer (2016) and 'cycling' to the model for cyclist from di Prampero et al. (1979).

v

speed of cyclist (km / h), only for method = 'cycling'.

Details

From the digital elevation model, transition slopes, energy costs and conductances (1 / work) are computed based on the model described in Pontzer (2016).

Value

A list with elements a rasterStack of the digital elevation model, slope, energy landscape, and conductance and the conductance as a transitionLayer for path analysis.

References

Etten, J. van. (2017). R Package gdistance: Distances and Routes on Geographical Grids. Journal of Statistical Software, 76(1), 1–21. doi: 10.18637/jss.v076.i13.

Pontzer, H. (2016). A unified theory for the energy cost of legged locomotion. Biology Letters, 12(2), 20150935. doi: 10.1098/rsbl.2015.0935.

di Prampero, P. E., Cortili, G., Mognoni, P., & Saibene, F. (1979). Equation of motion of a cyclist. Journal of Applied Physiology, 47(1), 201–206. doi: 10.1152/jappl.1979.47.1.201

Examples

library(raster)
data("volcano")
dem <- raster(volcano)
en <- enerscape(dem, 10, unit = "kcal", neigh = 16)

[Package enerscape version 0.1.3 Index]