dbhMetric {basifoR}  R Documentation 
This function can format tree diameters at breast height and tree
heights according to the sampling design of the Spanish National
Forest Inventory (SNFI). The function is used by other routines of
basifoR
to derive tree metrics, see Details
section. Implementation of this function using data sets of the
SNFI can be burdensome. Use dendroMetrics
instead to
recursively derive tree metrics.
dbhMetric(dbh, met = "d")
dbh 

met 

Replicates of tree diameter
'd'
are averaged. The tree heights
'h'
are formatted from mm
to
dm
for further evaluation of volume
equations. The basal areas are computed
transforming the diameters from mm
to
cm
and using the formula: ba (m2
tree1 ha1) = pi * d(cm)^2 * (4 *
1E4)^1
. The number of trees per hectare
'n'
are calculated considering the
sample design of the NFI: each plot consists
of four concentric subplots with radii
5, 10, 15,
and 25 m
. The
minimum diameters recorded in the subplots
are 7.5, 12.5, 22.5,
and 42.5
cm
respectively. Considering these, any of
four estimates is printed: 127.32,
31.83, 14.15
, or 5.09
.
numeric
. A tree metric: mean diameter (mm
), tree basal area
(m2 tree1
), number of trees (dimensionless), or
tree height (dm
).
Wilson Lara <wilarhen@gmail.com>, Cristobal Ordonez <a_cristo@pvs.uva.es>, Felipe Bravo <fbravo@pvs.uva.es>
dbh < dbhMetric(c(10.7, 11.5), 'h')# average tree height (dm)