Fish community composition driver spatial population synchrony

Animal populations often display coherent temporal fluctuations in their abundance, with far-ranging implications for species persistence and ecosystem stability. The key mechanisms driving spatial population synchrony include organismal dispersal, spatially correlated environmental dynamics (Moran effect) and concordant consumer–resource dynamics. Disentangling these mechanisms, however, is notoriously difficult in natural systems, and the extent to which the biotic environment (intensity and types of biotic interactions) mediates metapopulation dynamics remains a largely unanswered question. Using an extensive dataset of fish population abundance time-series across Europe, we provide evidence that higher beta-diversity is associated with reduced spatial population synchrony within river networks and demonstrate that these effects are independent from geographic separation, environmental dissimilarity, and Moran effects.

Larsen, S., L. Comte, X. Giam, K. Irving, P. Tedesco, and J. D. Olden. 2025. Community composition as an overlooked driver of spatial population synchrony. PNAS Nexus 4:pga272. Article