lorimerComp: Lorimer's competition index - Lorimer 1983

In johngodlee/compInd: Forest tree-tree competition indices

Lorimer's competition index - Lorimer 1983

Description

Lorimer's competition index - Lorimer 1983

Usage

lorimerComp(dbh, dist, focal_dbh, czr)

Arguments

dbh	vector of DBH (diameter at breast height) measurements of competitor trees
dist	vector of distances from focal tree to competitor trees
focal_dbh	DBH of focal tree
czr	Competition zone radius (CZR), normally based on plot-level stem density

Details

Value increases with dbh of competitor trees, decreases as the focal tree DBH increases. Value increases as the distance of competitor trees decreases. Tree distances are divided by the CZR in order to account for "stand age".

Value

value of competition index for focal tree

References

Lorimer, C. G. (1983). Tests of age-independent competition indices for individual trees in natural hardwood stands. Forest Ecology and Management. Volume 6. Pages 343-360.

See Also

lorimerCZR() to calculate the CZR

Examples

data(bicuar)
czr <- lorimerCZR(k = 1, n = nrow(bicuar))
nb <- nearNeighb(bicuar$x, bicuar$y, bicuar$stem_id, radius = czr) 
lapply(nb, function(x) {
  nb <- merge(x, bicuar, by.x = "nb", by.y = "stem_id", all.x = TRUE)
  focal_diam <- unique(bicuar[bicuar$stem_id == unique(nb$focal),"diam"])
  lorimerComp(nb$diam, nb$nb_dist, focal_diam, czr)
  })

johngodlee/compInd documentation built on Aug. 5, 2024, 8:44 a.m.