Fig. 4: Overall effects of mutualism on stability and function in complex ecosystems.

Column headings label the treatments described in Fig. 3. Mutualism is absent in Food Web (FW) treatments and present in corresponding multiplex treatments. Mutualisms are less intense in Low than in High rewards productivity treatments. Gray bars and associated µ′s describe means over all levels of initial diversity for all networks or “ecosystems” within each treatment at the end of N = 24,276 simulations. Shown are the total a diversity, b persistence, c biomass, d productivity and consumption rates, and the mean CVs of biomass of all e species within each ecosystem and f guilds within each ecosystem averaged over all the ecosystems within each treatment. Black error bars are 95% confidence intervals. Total rates of productivity and consumption were approximately equal (i.e. at steady state, all production is being consumed) so they are shown in one row (d).