Dispersal traits interact with dynamic connectivity to affect metapopulation growth and stability

Abstract: Many marine benthic species undergo a pelagic larval stage during which larvae are transported by ocean currents over a broad range of spatial and temporal scales. Although metapopulation theory predicts how stochastic dispersal can alter the stability of metapopulations, little is known about how dispersal-related traits such as spawning time and larval duration interact with spatiotemporal connectivity to affect metapopulation growth and stability. We used stochastic models and stage-structured metapopulation dynamics to study the interacting effects of ocean currents and dispersal traits on regional growth and stability. We derived stochastic metapopulation growth and stability, which predict the strong impact of local density regulation on the response of metapopulation to dynamic connectivity: temporal variance, positive (negative) covariance, and negative (positive) autocorrelation in connectivity deflate (inflate) density-independent growth. Yet, stability decreases (increases) with temporal variance and positive (negative) covariance of connectivity. We applied our derived metrics to simulated connectivity along the coast of British Colombia (Canada) over a range of spawning time (ST) and pelagic larval duration (PLD). Our analysis shows strong interactions between statistical components of connectivity, dispersal-related traits, and metapopulation growth and stability. The non-monotonic response of metapopulation stability to PLD was driven by mean of connectivity over short PLDs (< 36 days), with a decrease in mean connectivity and stability with PLD. Over longer PLDs, temporal variance in connectivity had a dominant effect, with both a decrease in temporal variance of connectivity and an increase stability with PLDs > 36 days. We therefore use a trait-based framework and partitioning the relative importance of spatial and temporal components of stochastic marine dispersal, to inform species response through climate-induced changes in larval transport and in dispersal-related traits.

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Recommended citation: Bani, R., Fortin, M. J., Daigle, R. M., & Guichard, F, 2018. Dispersal traits interact with dynamic connectivity to affect metapopulation growth and stability. Theoretical Ecology, 1-17.