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Native or domestic forage is the most cost effective feed source for ruminants production. Management of forage production and utilization on ranges and pastures to achieve sustained productivity and profitability requires sound management decisions. These decisions must be supported by knowledge of forage plant biology and system function.

A static optimum management solution does not exist because both environmental and economic components of the system are highly variable through time. Consequently, management prescriptions must be sufficiently flexible to accommodate a variety of inputs on various time scales.

For nine consecutive years (1987-1995) an American - Israeli team developed a system to measure the impact of plant manipulation on herbage production. The trials were conducted under controlled grazing conditions with animals (cattle in our case or sheep) or by simulation of grazing by clipping plants raised in containers. We propose to apply this acquired knowledge on the Chinese rangelands in order to determine the pertinent data needed to improve management in these rangelands.

Empirical field research cannot provide sufficiently diverse information to address all of the potential managerial scenarios encountered. Simulation modeling is a proven tool for investigating system function and developing decision criteria for management; however, effective models require experimental data for parameterization and validation.

The potential for managerial manipulation could be evaluated in several annual and perennial species utilizing destructive harvests and controlled grazing trials.

Results from these experiments will be used to parameterize biomass partitioning between reproductive and vegetative growth sub- models to be incorporated into an existing forage growth model for economically important annual and perennial grasses.