Biomass

Biomass 

(1) Biological material composed of organisms that are alive or have lived until recently. It is usually composed of plants or plant materials and is defined as ligninated biomass.  Biomass as an energy source can be utilized either by direct combustion or indirectly by converting biomass into different biofuel forms by different methods (thermal, chemical and biochemical).

(2) The total weight possessed by living organisms belonging to a species or to a society of various species at any given time. Biomass also means live weight. That is, it covers the living weight of all plants in a certain part of any place. This is sometimes also referred to as vegetable and animal mass.

(3) The total amount of living things still living in a unit area of land (or per unit volume in a body of water) and the remains of living things that have just died there, and of the crops harvested (or hunted) from the creatures there, available at a given time under consideration. Biomass is often referred to as dry weight and is considered a measure of the amount of "energy" (ecosystem efficiency) produced in that area.