Biomass functions

About biomass calculations in Heureka

In Heureka the amount of biomass is caclulated with different functions depending on tree species, tree age and tree fraction (what part of the tree).

Functions used

Established stands, above ground

For established stands (i.e. mean heigth ≥ 7m) you can choose either Petersson 1999 or Marklund . This is done on control table Production Model.

Young stands, above ground

For young stands, above ground tree biomass is calculated with Claesson et al 2001

Stumps and roots ≥ 2 mm

Biomass in stumps and and roots are calculated with Petersson & Ståhl (2006). These functions include roots with a diameter ≥ 2 mm. Today there are no biomass for stumps and roots in young stands, but starting from Heureka version 2.4 Petersson & Ståhl (2006) are used also in young stands.

Functions used when selected Marklund for above-ground biomass in established stands

In Marklund (1988) there are several alternative function for each species and tree fractions. The functions used in Heureka are listed in the table below.

'	Species	'	'
Tree fraction	Pine	Spruce	Birch
Trunc without bark, excluding stump	T-6	G-5	B5
Living branches	T-14	G-12	B13
Dead branches	T-22	G-20	B-17
Bark	T-2 minus T-6	G-2 minus G-5	B-8
Foliage	T-19	G-17	Repola 2008

Correction for other species than pine, spruce or birch

The functions desribed above are available for pine, spruce and birch. For other broad-leaves than birch, the birch functions are used but then calibrated using conversion factors between the subject tree species "normal" wood density and the wood density for birch according to http://sv.wikipedia.org/wiki/Trädslag. For larch and lodgepole pine, the functions for pine are used, and then adjusted with the corresponding conversion factors.