Influence of soil heterogeneity and competition on growth features of three meadow species

The effect of competition and artificially created soil heterogeneity was studied in a pot experiment. A tussock grass, Holcus lanatus, and the rhizomatous sedge Carex hartmanii were grown alone and in combination with another tussock grass, Molinia caerulea, in homogeneous and heterogeneous soil treatments. The heterogeneous treatment consisted of four compartments, two nutrient rich and two nutrient poor. In the homogenous treatment total nutrient content was the same as in the heterogeneous treatment. Soil heterogeneity increased M. caerulea total production, and increased C. hartmanii root:shoot ratio; no effect on H. lanatus was observed. Both M. caerulea and C. hartmanii were able to place their underground organs preferentially into nutrient rich patches. M. caerulea and H. lanatus total biomass was lower in the presence of the competitor; C. hartmanii responded to competition only by increased allocation to rhizoms. M. caerulea was more affected by competition in the heterogeneous environment.