Figure 4

Population densities of species with respect to the basal grazing intensity G. (a–h) The grazing intensity of a species increases as the fecundity increases, i.e., \({g}_{i}=G+G^{\prime} (20-i)\) and B_i = B−0.002(i-1) for i = 1, 2, …, s), indicating a trade-off between the birth rate and grazing intensity of a species. (i–p) The grazing intensity decreases as the fecundity increases, i.e., \({g}_{i}=G+G^{\prime} (i-1)\) and B_i = B−0.002(i-1) for i = 1, 2, …, s), indicating that inferior species are eaten more often by grazers. (a–d,i–l) The result of a single run. (e–h,m–p) The average of 30 runs. The basal grazing rates are (a,e,i,m) G = 0.05, (b,f,j,n) G = 0.1, (c,g,k,o) G = 0.3, and (d,h,l,p) G = 0.5. The parameters are as follows: interspecific grazing difference, G′ = 0.0005; basal fecundity, B = 1; initial species density, I_i = 0.03 (for all species); density of grazer cells, I_y = 0.4; and dispersal distance, P = 40. The lattice size is 100 × 100.