biomass

Short definition from Wiktionary

Noun

1. 1
   The total mass of a living thing or a part thereof (such as a cell).
2. 2
   The total mass of all, or a specified category of, living things within a specific area, habitat, etc.
3. 3
   Organic matter from living things which were recently alive (especially vegetation) used as a fuel or source of energy, especially if cultivated for that purpose; also, fuel produced from such organic matter; biofuel.