Spatial synchrony in stream fish populations: influence of species traits

Abstract

International audienceSpatial synchrony in population dynamics has been identified in most taxonomic groups. Numerous studies have reported varying levels of spatial synchrony among closely-related species, suggesting that species' characteristics may play a role in determining the level of synchrony. However, few studies have attempted to relate this synchrony to the ecological characteristics and/or life-history traits of species. Yet, as to some extent the extinction risk may be related to synchrony patterns, identifying a link between species' characteristics and spatial synchrony is crucial, and would help us to define effective conservation planning. Here, we investigated whether species attributes and temperature synchrony (i.e. a proxy of the Moran effect) account for the differences in spatial population synchrony observed in 27 stream fish species in France. After measuring and testing the level of synchrony for each species, we performed a comparative analysis to detect the phylogenetic signal of these levels, and to construct various multi-predictor models with species traits and temperature synchrony as covariates, while taking phylogenetic relatedness into account. We then performed model averaging on selected models to take model uncertainty into account in our parameter estimates. Fifteen of the 27 species displayed a significant level of synchrony. Synchrony was weak, but highly variable between species, and was not conserved across the phylogeny. We found that some species' characteristics significantly influenced synchrony levels. Indeed, the average model indicated that species associated with greater dispersal abilities, lower thermal tolerance, and opportunistic strategy displayed a higher degree of synchrony. These findings indicate that phylogeny and spatial temperature synchrony do not provide information pertinent for explaining the variations in species' synchrony levels, whereas the dispersal abilities, the life-history strategies and the upper thermal tolerance limits of species do appear to be quite reliable predictors of synchrony levels

The spatial scale of time‐lagged population synchrony increases with species dispersal distance

“…Ours is the first study to show that the distance at which dispersal most strongly produces time‐lagged population synchronization is correlated with empirical estimates of dispersal distance. This contributes to our understanding of the mechanisms driving population synchrony, adding to the growing body of literature suggesting that dispersal can synchronize populations (e.g., Chevalier et al, ; Paradis et al, ). These results also provide indirect support for Bearup, Petrovskii, Blackshaw, and Hastings (), who suggested that environmental effects on population synchrony could be distinguished from dispersal effects on population synchrony because the former cause unlagged synchrony, whereas the latter cause time‐lagged synchrony.…”

“…Prior empirical studies have found that the average strength of synchrony between populations increases with species dispersal ability (Chevalier, Laffaille, & Grenouillet, ; Paradis, Baillie, Sutherland, & Gregory, ). However, to our knowledge the hypothesis that time‐lagged population synchrony is strongest at the distances a species typically disperses has not been well tested.…”

Effects of life‐history traits on stream fish abundances across spatial scales

“…However, these were for “periodic” species (optimising fecundity at the expense of the other two traits), which are poorly represented in wadeable streams because they are large‐bodied and require predictable variations in abiotic conditions (Mims & Olden, ; Olden & Kennard, ). Chevalier et al () found that recruitment of opportunistic strategists (i.e. early maturing serial spawners with small clutch sizes) was more correlated than other life‐history strategists.…”

“…life history and dispersal) that have been shown to affect other ecological process such as recruitment synchrony (e.g. Chevalier et al, ) and community structure (e.g. de Bie et al, ), but are yet to be examined for spatial patterns of stream fish abundance.…”

Similarity in seasonal flow regimes, not regional environmental classifications explain synchrony in brown trout population dynamics in France

“…While dispersal could explain differences in degrees of synchrony among distinct species (Chevalier et al, 2014), it seems more likely to bring populations into synchrony at a local scale than at a regional scale (Sutcliffe, While dispersal could explain differences in degrees of synchrony among distinct species (Chevalier et al, 2014), it seems more likely to bring populations into synchrony at a local scale than at a regional scale (Sutcliffe, …”