Shoot Production and Biomass Transfer of Big Sacaton [Sporobolus wrightii]

Abstract

The annual pattern of above-ground live biomass, recent dead standing biomass, old dead standing biomass, and standing crop of big sacaton (Sporobolus wrightii Monro) grassland community in semiarid Arizona was studied over a 3-year period. Live biomass was produced throughout the year but peak production, over the 3 years, was in August. Peak biomass production was 296 g m-2 in 1 wet summer and averaged 133 g m-2 over 2 dry summers. Recent dead standing biomass was greatest in spring and least in summer, over the 3 years. Transfer of recent dead standing biomass to old dead standing biomass was precipitation and temperature dependent. Old dead standing biomass was greatest in summer, least in winter, and was primarily composed of dead seed stalks. Livestock management of big sacaton grasslands should possibly be distinct from adjacent upland areas.