Fig. 2.

Spatial structure reduces diversity compared to the well-mixed limit of instantaneous nutrient diffusion. (A, Upper) A well-mixed population of 10 species with equal initial populations competing for 2 nutrients. All 10 coexist at steady state. (A, Lower) Same as A, Upper, but with different initial populations. The community reaches a new steady state. (A, Upper, Inset) Strategies ${\overrightarrow{\alpha }}_{\sigma }$ and resource supply $\overrightarrow{s}=\left(0.4,0.6\right)$. (B, Upper) Same species and nutrient supply as A, but in a spatial environment with nonzero nutrient diffusion time. Only 3 species survive. (B, Lower) Same as B, Upper, but with different initial populations. The community reaches the same steady state. (C) Fraction of initial species coexisting at steady state with $\overrightarrow{s}=\left(0.4,0.6\right)$; a population is considered extinct if $n_{\sigma }/L<10^{-6}$ (mean $\pm$ SD for 400 random sets of 10 strategies). The well-mixed model has survival fraction $0.99\pm 0.08$. (D) Effective number of species $M$ at steady state (mean $\pm$ SD for same strategies as C).