Table 1. Model equations.

Primary cheaters	$\frac{d{n}_{00}}{dt}=r_{00}{n}_{00}(1-\frac{n_{00}+\varphi n_{01}+\theta n_{10}+\psi n_{11}}{k+{\beta }_{0}R})-m{n}_{00}$
Secondary producers	$\frac{d{n}_{01}}{dt}=r_{01}{n}_{01}(1-\frac{\varphi n_{00}+n_{01}+\omega n_{10}+\nu n_{11})}{k+{\beta }_{0}R}-m{n}_{01}$
Primary producers	$\frac{d{n}_{10}}{dt}=r_{10}{n}_{10}(1-\frac{\theta n_{00}+\omega n_{01}+n_{10}+\mu n_{11}}{k+{\beta }_{1}R})-m{n}_{10}$
Global producers	$\frac{d{n}_{11}}{dt}=r_{11}{n}_{11}(1-\frac{\psi n_{00}+\nu n_{01}+\mu n_{10}+n_{11}}{k+{\beta }_{1}R})-m{n}_{11}$
Resource	$\frac{dR}{dt}=g(n_{10}+n_{11})-lR$

Governing equations of the model under competition structure I, and the corresponding variables whose rates of change they describe. Time dependence of n and R have been suppressed for notational simplicity. Dependence of m on N and R has also been suppressed. The equations for competition structures II and III are shown in S2 and S3 Tables.