basal {dendrometry}

The basal area of stands

Description

The basal area is the cross sectional area of the bole or stem of a tree at breast height.

Usage

basal(
  dbh,
  area,
  factor1 = "",
  factor2 = "",
  factor3 = "",
  data,
  constant = 100
)

Arguments

dbh

numeric vector of diameter. If data is specified, character indicating name of variable of data containing dbh values.

area

numeric, area of a plot (see details for unit).

factor1, factor2, factor3

character, optional variables of the data frame that define subsets to consider.

data

data frame containing optional factors factor1,factor2,factor3.

constant

numeric, used to convert diameter unit. Default is 100 (see details)

Details

If area is expressed in ha and dbh expressed in cm, the basal area unit is cm²/ha when constant = 1. In order to convert centimeter (cm) to meter (m) for dbh, set constant = 100. Because 1m = 100 cm. Then, basal area unit will be m²/ha.

If dbh is in meter (m), and area in in hectare (ha), setting constant = 1 returns basal area in m²/ha.

If dbh is in feet, and area in acre, setting constant = 1 returns basal area in ft²/ac.

If dbh is in inch, and area in acre, setting constant = 12 returns basal area in feet²/acres (ft²/ac).

Value

A vector of basal area of stands. If more than one factor set, a list.