n. The oven-dry mass of organic matter per unit of ground area.
Biomass includes both the mass of plants (phytomass) and the mass of animals (zoomass). In forestry and wildland fire applications, biomass refers specifically to phytomass. Individual components of biomass can be identified specifically; for example, total above-ground biomass is the mass of all parts of trees, shrubs, and grasses occurring above the ground surface, specifically excluding below-ground plant mass consisting of roots.
In some forest management documents, biomass is (wrongly) considered to be all non-merchantable material (live or dead) that can be chipped and burned to generate power. Removal of such material has been touted as a fuel reduction strategy, and the term “biomass” can therefore be confused with fuel load. However, removal of non-merchantable trees reduces live ladder fuel and canopy fuel, often leaving surface fuel – composed primarily of dead organic matter – intact.