fgeo_habitat {fgeo.analyze}

Create habitat data from measures of topography.

Description

This function constructs habitat data based on elevation data. It calculates habitats in two steps:

1. It calculates mean elevation, convexity and slope for each quadrat.

2. It calculates habitats based on hierarchical clustering of the topographic metrics from step 1.

Usage

fgeo_habitat(elev, gridsize, n, ...)

Arguments

elev

One of these:

• A dataframe containing elevation data, with columns gx, gy, and elev, or x, y, and elev (e.g. fgeo.x::elevation$col).

• A ForestGEO-like elevation list with elements xdim and ydim giving plot dimensions, and element col containing a dataframe as described in the previous item (e.g. fgeo.x::elevation).

gridsize

Number giving the size of each quadrat for which a habitat is calculated. Commonly, gridsize = 20.

n

Integer. Number of cluster-groups to construct (passed to the argument k to stats::cutree()).

...

Arguments passed to fgeo_topography().

Value

A dataframe of subclass fgeo_habitat, with columns gx and gy, rounded with accuracy determined by gridsize, and column habitats, with as many distinct integer values as determined by the argument n.

Author(s)

Richard Condit.

See Also

fgeo.plot::autoplot.fgeo_habitat(), fgeo_topography().

Other habitat functions: fgeo_topography(), tt_test()

Other functions to construct fgeo classes: fgeo_topography()

Examples

assert_is_installed("fgeo.x")

# Input a ForestGEO-like elevation list or dataframe
elevation_ls <- fgeo.x::elevation
habitats <- fgeo_habitat(
  elevation_ls,
  gridsize = 20, n = 4
)

str(habitats)

# Habitat data is useful for calculating species-habitat associations
census <- fgeo.x::tree6_3species
as_tibble(
  tt_test(census, habitats)
)