forestSAS (version 1.0.1)

crowding: A forest spatial structure index characterizing crowding degree.

Description

Analyze the crowding degree of a neighborhood unit according to the overlapping of the crown in spatial micro-environment which clearly define the crowding degree for a reference tree and its four nearest neighbors, and to some degree of the competition pressure on it as well.

Usage

crowding(x)

Arguments

x

A vector composed by 5 crowding degree value

Value

Result will retrun five values,0,0.25,0.5,0.75,1,which means none, one, two, three, or four overlap of nearest neighbors with reference tree,respectively.

References

Hu YB, Hui GY. 2015. How to describe the crowding degree of trees based on the relationship of neighboring trees. Journal of Beijing Forestry University. 37(9):1-8.

Examples

# NOT RUN {
overlap1<-c(-0.5,-0.4,-0.3,-0.2) ##negative means no overlap
overlap2<-c(-0.5,-0.4,-0.3,0.2)  ##positive means overlap
overlap3<-c(-0.5,-0.4,0.3,0.2)
overlap4<-c(-0.5,0.4,0.3,0.2)
overlap5<-c(0.5,0.4,0.3,0.2)

crowding1<-crowding(overlap1)
crowding1
crowding2<-crowding(overlap2)
crowding2
crowding3<-crowding(overlap3)
crowding3
crowding4<-crowding(overlap4)
crowding4
crowding5<-crowding(overlap5)
crowding5
# }