Leaf area index is the total area of all leaves of plants relative to the ground surface, within a give area. It is slightly different than a simple measure of canopy cover because it accounts for all layers of vegetation rather than only the top most layer. Leaf area index is expressed as a percentage, which can exceed 100% in abundant vegetation. Leaf area is an indicator of biomass at a site.
Key areas are sampling sites deliberately selected, based mainly on professional judgement, in rangeland inventory or monitoring programs to be representative of the entire management unit. Data from key areas are interpreted as an indicative guide of average responses to land use throughout the management unit.
Susan Muir (New Mexico State University)
Mitchel P. McClaran (University of Arizona)
16 September 1997 (Draft for Review)
Current year's growth is the above-ground biomass produced during the previous 12 months.
Ground cover describes the proportion of the soil surface covered by some type of protective material, which usually includes litter, gravel, rocks, microphytic crusts, in addition to standing plant material. Unprotected bare soil can be determined as
Bare soil = 100% - Ground Cover
Society for Range Management. 1989. A glossary of terms used in range management. Society for Range Management, Denver, CO. 3rd ed. p 8.