One of the main obsessions in the laboratory is to build robust ecological theories for communities composed of many species. This is especially important in competitive systems–much of our  understanding in this area descends from the analysis of the dynamics of two competitors.

In a new review published this week in Nature, Jonathan Levine, Jordi Bascompte, Peter Adler, and yours truly provide a roadmap for extending these considerations to systems with more than two species. Interestingly, certain mechanisms, such as higher-order interactions and intransitive competition, can only be studied in high-dimensional systems. You can read the paper here:

Jonathan M. Levine, Jordi Bascompte, Peter B. Adler & Stefano Allesina
Beyond pairwise mechanisms of species coexistence in complex communities
Nature, 2017

Here’s the “Outlook”:

In this Review, we suggest that coexistence mechanisms that emerge only in systems with more than two competitors exert a largely unexplored control over the maintenance of diversity in species-rich communities. We also highlight that when studying more than two competitors, ecologists necessarily confront an ecological network. However, it remains largely unknown how the structure of the network influences coexistence. The sparseness of evidence results from the intractability of empirically evaluating competition between many species and the technical difficulties that are inherent in tightly coupling theory to data. Despite these challenges, there are compelling reasons to deepen our understanding of these more complex mechanisms of coexistence. Armed with advances in data-driven modelling and network analyses that have been developed for multitrophic systems, ecologists are well-positioned to determine, for at least some species-rich communities, how much of the coexistence results from mechanisms that emerge only in diverse systems. Few other questions in ecology have such great potential to radically shift how we think about the maintenance and fragility of biodiversity.