Eriksson_frequency: Volume Frequency for Norway spruce stands.
In Silviculturalist/forester: Forest Science and Forestry

Eriksson_frequency

R Documentation

Volume Frequency for Norway spruce stands.

Description

This is an attempt to follow the instructions given by Eriksson. From functions relating easily gathered information to a fitted stem and volume distribution respectively, a skewed normal distribution is estimated. From an expanded series, the frequency of each class is then calculated.

Usage

Eriksson_1976_volume_frequency(
  age,
  dominant_height,
  QMD,
  volume,
  stems,
  class_width_cm = 2,
  class_middle = 1.5
)

Eriksson_1976_stem_frequency(
  age,
  dominant_height,
  QMD,
  stems,
  class_width_cm = 2,
  class_middle = 1.5
)

Arguments

`age`	Stand age at breast height (1.3 m)
`dominant_height`	Dominant height, in metres.
`QMD`	Quadratic Mean Diameter (cm).
`volume`	Volume of stand, cu.m.
`stems`	Stems per hectare.
`class_width_cm`	Default 2 cm. Range between upper and lower class limit.
`class_middle`	Arithmetic mean of the sum of the upper and lower limit.

Details

Volume and Stem Frequencies for even-aged Norway Spruce stands from the Great Yield Investigation (Näslund 1971).

TESTED ONLY FOR 2 CM class width!

Value

Frequency, in percent.

Source

Eriksson, H. 1976. Yield of Norway spruce in Sweden. Research Notes. Dept. of. Forest Yield Research. Nr. 41. Royal College of Forestry. Stockholm. p. 161-165; 279-284.

Silviculturalist/forester documentation built on April 20, 2024, 2:13 p.m.