The stability of isolated communities is determined by foodweb complexity. However, it is unclear how local stability interacts with dispersal in multitrophic metacommunities to shape biodiversity patterns. Furthermore, metacommunity dynamics in landscapes with non-trivial and dynamic structures are less understood. We aim to evaluate the influence of local stabilizing factors versus dispersal in determining the sensitivity of metacommunity biodiversity to increasing site availability asynchrony. Additionally, we assess the role of foodweb and landscape complexities as modulating factors. To achieve these goals, we developed a model based on random matrices for local communities linked by stochastic dispersal over explicit, dynamic landscapes. Both local and regional stabilizing factors determined the sensitivity of metacommunities to landscape asynchrony. Local factors were more influential in landscapes with fewer sites and lower modularity, and in more complex foodwebs. We delve into the mechanisms underlying our results and discuss potential extensions of our study.

Ecological theory recognizes the importance of the variety of species for maintaining the functioning of ecosystems and their derived services. We assert that when studying the effects of shifts in biodiversity levels using mathematical models, their dynamics must be sensitive to the variety of species traits but not to raw species numbers, a property that we call scale--invariance. We present a testing procedure for verifying scale--invariance of ecological network models ---with or without trait adaptation--- expressed as ODEs. Furthermore, we applied our test to several influential models used for evaluating biodiversity effects on ecosystem functioning. In most of the surveyed studies the equations failed our test. This raises doubts about the validity of previous results and calls for revisiting the theory derived from these studies. Our results foster the creation of artifact--free models, a necessary step towards building a more robust theory of biodiversity--driven ecosystem functioning.

Ecological theory recognizes the importance of the variety of species for maintaining the functioning of ecosystems and their derived services. In this context, adaptive changes in functional traits plays a crucial role. We assert that when studying the effects of shifts in biodiversity levels using mathematical models, they must be scale--invariant, i.e., should be sensitive to the variety of species traits but not to raw species numbers. We present a testing procedure for verifying scale--invariance of eco--evolutionary network models expressed as ODEs. Furthermore, we applied our test to several influential models used for evaluating biodiversity effects on ecosystem functioning. In most of the surveyed studies the equations used failed our test. This raises doubts about the validity of previous results and calls for revisiting the theory derived from these studies. Our results foster the creation of artifact--free models, a necessary step towards building a more robust theory of ecosystem functioning.