GapsSpatPattern {ForestGapR}

Spatial Pattern Analysis of Forest Canopy Gaps

Description

This function computes second order statistics of forest canopy gaps (raster::RasterLayer) to sp::SpatialPointsDataFrame objects

Usage

GapsSpatPattern(gap_SPDF_layer, chm_layer)

Arguments

gap_SPDF_layer

A sp::SpatialPointsDataFrame object of the forest canopy gaps. Output of GapSPDF() function. An object of the class sp::SpatialPointsDataFrame

chm_layer

ALS-derived Canopy Height Model (CHM) (raster::RasterLayer) object. An object of the class raster::RasterLayer.

Value

A plot with Ripley's K- and L-functions. Value of Clark-Evans index (R) and test for randomness (R=1), aggregation (R<1) or uniform distribution (R>1).

Author(s)

Ruben Valbuena and Carlos Alberto Silva.

References

spatstat.explore-package, see Lest, Kest and clarkevans.test

Examples

# This takes > 5 seconds!

# Loading raster and viridis libraries
library(raster)
library(viridis)

# ALS-derived CHM from Fazenda Cauxi - Brazilian tropical forest
data(ALS_CHM_CAU_2012)
data(ALS_CHM_CAU_2014)

# set height thresholds (e.g. 10 meters)
threshold <- 10
size <- c(1, 1000) # m2

# Detecting forest gaps
gaps_cau2012 <- getForestGaps(chm_layer = ALS_CHM_CAU_2012, threshold = threshold, size = size)
gaps_cau2014 <- getForestGaps(chm_layer = ALS_CHM_CAU_2014, threshold = threshold, size = size)

# Converting raster layers to SpatialPolygonsDataFrame
gaps_cau2012_spdf <- GapSPDF(gap_layer = gaps_cau2012)
gaps_cau2014_spdf <- GapSPDF(gap_layer = gaps_cau2014)

# Spatial pattern analysis of each year
gaps_cau2012_SpatPattern <- GapsSpatPattern(gaps_cau2012_spdf, ALS_CHM_CAU_2012)
gaps_cau2014_SpatPattern <- GapsSpatPattern(gaps_cau2014_spdf, ALS_CHM_CAU_2014)