Biomass is a general term that encompasses many special attributes. For example, inventory or monitoring programs focusing on grazing applications may only want to estimate available forage, whereas those addressing ecological perspectives may need to estimate productivity. In some instances, the objectives of the sampling program could be tied to current year's production, while at other times an estimate of dead or alive biomass is most relevant.
The decision of exactly what to measure depends on sampling objectives and availability of resources, and should be clearly supported by ground rules.
References and Further Reading
(Note: pdf files require Adobe Acrobat (free) to view)
Bonham, C.D. 1989. Measurements of terrestrial vegetation. John Wiley Sons. New York, NY. pp 216-217.
Cox, J.R. 1992. Lehmann lovegrass live component biomass and chemical composition. Journal of Range Management 45:523-527. (pdf)
Martin, M.H., Cox, J.R., and F.F. Ibarra. 1995. Climatic effects on buffelgrass productivity in the Sonoran Desert. Journal of Range Management 48:60-63.