Forage Mass

The total dry weight of forage per unit area of land, usually above ground level and at a defined reference level. This definition can be appropriately altered to be specific to herbage or browse by substituting these terms in place of forage. cf. available forage, herbage

Source
Society for Range Management. 1998. Glossary of terms used in range management, fourth edition. Edited by the Glossary Update Task Group, Thomas E. Bedell, Chairman. Used with permission.