74Destructive sampling method for estimating below-ground biomass

74 Destructive sampling method for estimating below-ground biomass

(1) This section sets out the destructive sampling method for section 73.

(2) The roots of each individual biomass sample tree must be excavated by defining those parts of the root system that will be included in the sampling and measurement process.

(3) Roots that have a diameter of less than 2 millimetres must not be included in the processes specified in subsections (5) to (14), except where the roots are attached to larger root sections.

(4) A root system must be cleaned so that contamination from soil and any other contaminants is minimised.

(5) Once excavated and cleaned, the root system must be divided into its separate biomass components which must include at least:

(a) the tap root or lignotuber; and

(b) the lateral roots.

(6) The total wet weight for each of the separated below‑ground biomass components must be recorded and documented in an allometric report as specified in section 66.

(7) Subject to subsection (14), for each biomass sample tree at least 3 representative sub‑samples must be collected from each biomass component and weighed immediately after carrying out the weighing for subsection (6).

(8) Subject to subsection (14), the wet‑weight of all sub‑samples specified in subsection (7) must be recorded and documented in an allometric report.

(9) The following must be oven‑dried to constant weight between 70 and 80 degrees Celsius:

(a) the sub‑samples specified in subsection (7);

(b) any biomass component being used under subsection (14).

(10) The following must be recorded and documented in an allometric report as specified in section 66:

(a) the dry‑weight of the sub‑samples that have been oven‑dried in accordance with subsection (9);

(b) the dry weight of any biomass component being used under subsection (14).

(11) The dry‑wet weight ratio for each of the sub‑samples, and of any biomass component being used under subsection (14), must be calculated by dividing dry weight by wet weight.

(12) The average of the dry‑wet weight ratios for each component must be calculated.

(13) The dry weight of each below‑ground biomass component of the biomass sample tree must be estimated using Equation 31 and applying the average of the dry‑wet weight ratios as specified in subsection (12).

(14) As an alternative to the sub‑samples specified in subsection (7) and (8), the entire biomass component may be used in the processes specified in subsections (8) to (11).