Vfm: tree volume information

Description

Wrapper to get specific type of volume from taper curve

Usage

Vfm(obj)
Efm(obj, stH = 0.01)
VolR(obj)
VolE(obj)
VolFAO(obj)
Vfm_phys(obj)
Efm_phys(obj, stH = 0.01)

Value

vector of volume estimates

Arguments

obj: a object of class 'tprTrees'
stH: assumed or known relative or absolute stump height, from which volume calculation should starts, defaults to 0.01

Functions

Efm(): Efm, i.e. coarse wood excl. bark from Ht=stH*Ht to Dob=7cm
VolR(): VolR: Volume from H=0 to D=7cm over bark, measured as 2m sections
VolE(): VolE: sum of volume of default assortments according to RVR
VolFAO(): VolFAO: from stump to tree top incl. bark; if dbh < 7cm using tabulated values
Vfm_phys(): Vfm_phys physical volume of tree incl. bark from A=0
Efm_phys(): Efm_phys physical volume of tree excl. bark from A=0.1*Ht

Details

wrapper functions around tprVolume, which return specific definitions of stem volume.

Function Efm uses parameter stH to define starting point, i.e. stump height, of volume calculation. stH can be defined relative to total tree height (0 < stH <= 1) or in absolute measure (unit=cm) in case stH > 1

VolE calculates as the sum of volume of default assortments (stem wood, top log, industrial wood, X-wood, non-usuable wood according to RVR. For dbh < 7cm a linear regression is applied.

VolFAO calculates tree volume starting from stump up to tree top (in contrast to german definition, which uses D=7cm over bark), and includes bark component. Stump height is defined as 1% of tree height. Volume calculation is based on 2m-sections. For trees with dbh < 7cm, tabulated values are used, see Riedel et al. (2017) for details (e.g. p.35, table 5.6).

Vfm_phys is equal to Vfm, except that the taper curve is numerically integrated, by use of section length of 0.01m. This is relevant if biomass or nutrient export is to be calculate. Numerical integration is quite slow.

Efm_phys is equal to Efm, except that the taper curve is numerically integrated, by use of section length of 0.01m. This is relevant if biomass or nutrient export is to be calculate. Numerical integration is quite slow.

References

Riedel, T. and Hennig, P. and Kroiher, F. and Polley, H. and Schwitzgebel, F. (2017): Die dritte Bundeswaldinventur (BWI 2012). Inventur- und Auswertemethoden. 124 pages.

Examples

Run this code

t <- tprTrees() # constructor of class 'tprTrees'
Vfm(t)
Efm(t)
Efm(t, stH=0.01) # stump height = 1\% of tree height
Efm(t, stH=10) # stump height=10cm
VolR(t)
VolE(t)
VolFAO(t)
Vfm_phys(t) # slower since much more evaluations of taper curve (every 1 cm)
Efm_phys(t, stH=0.01) # slower since much more evaluations of taper curve (every 1 cm)

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