Asymmetry in marginal population performance foreshadows widespread species range shifts

Pulido, F.; Castagneyrol, B.; Rodriguez-Sanchez, F.; Caceres, Y.; Pardo, A.; Moracho, E.; Kollmann, J.; Valladares, F.; Ehrlen, J.; Jump, A. S.; Svenning, J.-C.; Hampe, A.

doi:10.1101/529560

bioRxiv · 10.1101/529560

Asymmetry in marginal population performance foreshadows widespread species range shifts

Pulido, F.·Castagneyrol, B.·Rodriguez-Sanchez, F.·Caceres, Y.·Pardo, A.·Moracho, E.·Kollmann, J.·Valladares, F.·Ehrlen, J.·Jump, A. S.·Svenning, J.-C.·Hampe, A.

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Abstract

AimRange shifts are expected to occur when populations at one range margin perform better than those at the other margin, yet no global trend in population performances at range margins has been demonstrated empirically across a wide range of taxa and biomes. Here we test the prediction that, if impacts of ongoing climate change on population performance are widespread, then populations from the high-latitude margin (HLM) should perform as well as or better than central populations, whereas populations at low-latitude margins (LLM) populations should perform worse. LocationGlobal Time period1898-2020 Major taxa studiedPlants and animals MethodsTo test our prediction, we used a meta-analysis quantifying the empirical support for asymmetry in the performance of high- and low-latitude margin populations compared to central populations. Performance estimates were derived from 51 papers involving 113 margin-centre comparisons from 54 species and 705 populations. We then related these performance differences to climatic differences among populations. We also tested whether patterns are consistent across taxonomic kingdoms (plants vs. animals) and across habitats (marine vs. terrestrial). ResultsPopulations at margins performed significantly worse than central populations and this trend was primarily driven by the low-latitude margin. Although the difference was of small magnitude, it was largely consistent across biological kingdoms and habitats. The differences in performance were positively related to the difference in average temperatures between populations during the period 1985-2016. Major conclusionsThe observed asymmetry in marginal population performance confirms predictions about the effects of global climate change. It indicates that changes in demographic rates in marginal populations, despite extensive short-term variation, can serve as early-warning signals of impending range shifts.

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Pulido, F., Castagneyrol, B., Rodriguez-Sanchez, F., Caceres, Y., Pardo, A., Moracho, E., Kollmann, J., Valladares, F., Ehrlen, J., Jump, A. S., Svenning, J.-C., Hampe, A.. 2019-01-24. Asymmetry in marginal population performance foreshadows widespread species range shifts. https://doi.org/10.1101/529560

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