The impacts of shading, fertilization and cutting on growth of Elymus nutans
光照，施肥及刈割对垂穗披碱草生长的影响

A study was conducted with Elymus nutans, a common species in alpine meadow in Gannan, to assess the effects of shading and fertilization on its growth and compensatory responses to simulated grazing. Results show that light and fertilization interacted in no-cutting treatments: aboveground biomass was greatest (3.239g per plant) at 43.5% light in a fertilized environment. For plants at 43.5% light in a fertilized environment, the compensation index for aboveground biomass was greater after late cutting than early cutting; cutting intensity had no effect, but compensation was the greatest after cutting twice. Aboveground biomass was greatest (4.500g per plant) at 43.5% light in a fertilized environment after a single early mild cutting. Cutting did not affect compensation in natural light environment without fertilizer. For the compensation principle, increased aboveground biomass was associated with decreased belowground biomass.