What is Biomass or Production?
Biomass is the total weight of living
organisms, including plants and animals, for a given area usually expressed as
kg/ha, lbs/acre, g/m2, etc. For most ecological investigations
and for the purposes of this course, "biomass" is a vegetation attribute that
refers to the weight of plant material
within a given area. Another commonly used term for biomass is "production"
which refers to how much vegetation is produced on an area.
The biomass on a site can be estimated by species (i.e., weight of each
individual plant species) or biomass can be estimated in groups such as growth
form (grass, forb, shrubs, or trees), plant longevity (annual or perennial),
or degree of woodiness (herbaceous or woody).
Terms for Biomass
Gross Primary Production = Total amount
of organic matter in an ecosystem including above ground (i.e., leaves and stems) and
below ground (i.e., roots) biomass. Also sometimes referred to as Net Primary
Residual Biomass = Amount of vegetation
remaining after grazing is completed.
Phytomass = Total weight of plant mass
per unit of area in an ecosystem.
= The amount of biomass at a given time. Usually refers to the amount of
above-ground plant biomass.
Peak Standing Crop = The maximum amount
of standing crop observed during a given year.
Forage = Herbage or browse that is
accessible and acceptable as food for grazing and browsing animals.
Herbage = Above ground biomass of
Browse = The portion or amount of woody
plants available for animal consumption. Usually current seasonís growth of
twigs and leaves.
Mast = Fruits, nuts, and seeds produced
by woody plants and used as food by animals.
Necromass = The accumulated dead biomass,