Integrating modeling and empiricism: Consumer-resource body-size ratios yield persistent complex ecological networks.
Brose, Ulrich*,1, 1 Darmstadt Technical University, Darmstadt, Germany
ABSTRACT- The instability of complex ecological network models has troubled ecologists for several decades. Here, I present an ecoinformatics approach to simulating complex ecological networks that is based on non-random network structures (who eats whom) and allometrically determined species physiological parameters. Generally, network stability as measured by species persistence in time series is higher in empirically-informed than in random networks. Most importantly, species persistence increases dramatically with consumer-resource body-size ratios. While persistence is low in networks with consumers that are smaller than their resources, increased consumer body sizes equilibrate the population dynamics and stabilize the networks. Interestingly, analyses of a global data base on consumer-resource body-size ratios indicate that the average ratios in natural communities are close to the maximum persistence level in simulated networks. In the simulations, the negative complexity-stability relationship found in networks with equally sized species is inverted to positive ones when consumer-resource body-size ratios are consistent with empirical values. These results indicate that consumer-resource body-size ratios can make a major contribution to stabilizing complex ecological communities. This illustrates that our understanding of patterns in natural communities such as empirical body-size ratios can greatly profit from ecoinformatics tools that allow dynamical analyses.
Key words: diversity-stability, allometric scaling, food webs, ecoinformatics
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