To allow for all roots down to 2 mm diameter, BiEqs described by Petersson and Ståhl (2006) were applied. These equations were constructed by calibrating Marklund’s data for sample
trees, which included only the stump and coarse roots, against data for about 80 new trees that were inventoried in a similar way but with additional detailed information of small woody root fractions remaining in the ground (down to 2 mm root diameter). Petersson and Ståhl’s (2006) trees were inventoried from six stands from the north, three stands from the middle and three stands from the southern part of Sweden. Sub-sampling of stump and roots and laboratory analyses were performed in a manner that tried to mimic the methodology used by Marklund (1988). Petersson and Ståhl’s (2006) BiEqs were used http://www.selleckchem.com/products/PLX-4032.html to predict the biomass of stumps and roots for Scots pine and Norway spruce, but their BiEq for birch was based on only 14 birches and this was considered too small a sample to provide
reliable results. Therefore, Petersson and Ståhl’s (2006) Norway spruce below-ground AZD2281 mouse biomass equations were applied to all broadleaved species. Above-ground referred to the biomass above stump height, which was assumed to be located at 1% of the tree height. The stem volume was defined as the volume of the stem including tip above stump height and bark, and it was estimated using Näslund’s (1947) single tree volume equations
based on 2390 Scots pines, 2425 Norway spruces and 1363 birches. As for the biomass equations, the data used in deriving the single tree volume equations corresponded to a wide variety of stand and site conditions and are representative of Swedish forests. For most sample trees, only tree species and stem diameter at breast height (dbh, 1.3 m above the imaged germination point) were used as independent variables in the regression equations. However, for a small proportion (basal area weighted) of sample trees, data are available for the height, age and crown height. Given measured variables of tree, stand and site, MycoClean Mycoplasma Removal Kit the function with the lowest root mean squared error (RMSE) were applied (Marklund, 1988 and Petersson and Ståhl, 2006). Biomass or volume referred to the biomass or volume of living trees with a stem diameter at breast height larger than 99 mm (threshold for trees that are positioned on the sample plots). A conversion factor of 0.50 was used to convert biomass (dry weight) to carbon equivalents (C) (ton). A stoichiometric conversion factor of 3.67 (44/12) was used to convert C to carbon dioxide equivalents (CO2).