Reproductive allocation of Elymus nutans under different planting densities and nitrogen fertilizing treatments

A pot experiment was conducted to study the response of the growth characteristics, reproductive allocation pattern of Elymus nutans to competition density and nutrient addition. The plant height, leaf length, panicle length, tiller number and each organ biomass of E.nutans had competition-density effects under different planting densities. Biomass allocation of each organ were constrained by the density and the reproductive biomass allocation reached the highest of 10.46% under lower density (20 seed·m-2). There were significant effects of high nitrogen fertilizer on each organ biomass. Meanwhile, the effects of nitrogen fertilizer on reproductive biomass showed the trend of the inverted “V” type. Each growth index of E.nutans was significantly positive (P0.01) correlated with each other under individual treatment of planting density or nitrogen fertilizer. There was “shift” trade-off relationship for resource allocation of each organ of E.nutans.