How spatial structure impacts biodiversity patterns: Linking species-sorting and mass-effect archetypes

Background/Question/Methods

: Understanding how spatial structure at a large spatial scale contributes to biodiversity is a key for conservation planning with spatial management. Despite the fundamentally spatial nature of processes taking place in ecosystems at such a large spatial scale, much of our theoretical understanding comes from spatially implicit systems, a special case of spatial structure in which patches are all connected to each other equally. In many real systems, both the connections among patches (i.e. network topology) and the distributions of environments across patches (i.e. spatial autocorrelation) are not arranged uniformly. Thus, using simulations, we first test whether the biodiversity patterns (i.e. alpha, beta, and gamma diversity) predicted by a model with the spatially implicit assumption can be generated with models assuming other spatial structures, including varying theoretical network structures and marine connectivity networks estimated based on ocean currents. Then, we analyse the simulation output and the spatial structures used as input to understand which aspects of spatial structure contributes to spatial processes simulated.

Results/Conclusions

: We found that the biodiversity patterns predicted by the spatially implicit systems are an extreme case, rather than general, when a wider variety of spatial structures are considered. We determined that more complex linear and tree-like spatial structures maintain higher regional biodiversity under strong dispersal. Finally, we show that these theoretical results are applicable to systems with more realistic and complex spatial structure in marine metacommunities. These results provide a better understanding of the role that complex spatial landscape structure plays in metacommunity processes, a necessary step to understanding how metacommunity processes relate to biodiversity conservation.