FBA 4

Non-Destructive Sampling

An assessment method where living vegetation or wood is measured directly in the field without felling or cutting (e.g., using allometric equations for live trees and roots, or geometric formulas for dead wood and stumps).

Destructive Sampling

An assessment method involving the complete harvesting, weighing, and laboratory processing (oven-drying) of physical biomass samples (used for understorey vegetation, forest litter, and soil organic matter).

Allometric Equation

A statistical and mathematical regression model that estimates the biomass or carbon content of a tree based on non-destructive field measurements such as DBH, height, and wood density. 

Root-to-Shoot Ratio Method

An indirect, non-destructive approach estimating belowground root biomass from calculated aboveground biomass using established allometric relationships.

Dead Standing Trees

Non-living upright tree remnants measured non-destructively using formulas for the volume of a cylinder for unbranched and branched parts.

Dead Felled Trees/Dead Lying Wood

Fallen logs, branches, and trunks with diameter > 5 cm and length > 0.5 m assessed non-destructively inside sampling transects.

Stump Remains

The low basal portion of a tree trunk left rooted in the soil after cutting, measured non-destructively as a cylinder.

Soil Bulk Density (BD)

The mass of dry soil per unit of bulk volume, sampled using cylindrical core rings to determine soil mass and soil organic carbon stock per hectare.

Oven-Dry Weight (ODW)

The constant moisture-free mass of a biomass or soil sample obtained after drying in an oven at 80 degree celciusfor understorey and litter, or 105 degree celcius for soil bulk density). 

Composite Sample

A representative mixture formed by thoroughly combining multiple subsamples taken across sampling plots to run homogeneous laboratory analyses.

Expansion Factor

A mathematical scaling multiplier based on the ratio of one hectare (10,000\text{ m}^2) to the plot frame area used to convert sample dry weight into biomass density per hectare.

Carbon Fraction

The proportion of dry biomass that consists of elemental carbon, where 50% is commonly assumed, 47% is the IPCC default, and 45% is the recommended standard for tropical trees in the Philippines.