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Aim: Global climate change has been linked to shifts in species' geographic and elevational distributions, with taxa varying in responsiveness. This variation may be due to a time lag in response or climate alone not being a simple determinant of distribution limits. To tease apart the role of climate in distribution, we compared the temperature response of predicted occurrence revealed by ecological niche modelling (ENM) on historical climate with that of performance in a multi‐population transplant experiment. Congruence would support that climate is a main driver of distribution limits of a species. Location: North America. Taxon: Arabidopsis lyrata subsp. lyrata. Methods: Seeds of 20 populations of North American Arabidopsis lyrata from across the entire range were collected, propagated and then sown along a latitudinal transect across and beyond the species' range. Lifetime performance was related to the main niche‐ and range‐determining climatic variable revealed by ENM. Results: Lifetime performance did not consistently decline towards the high‐latitude range limit, but it did so towards the low‐latitude range limit. This decline was slightly weaker for low‐latitude populations, indicating divergent climate adaptation. The overall performance curve on the field‐measured minimum temperature in early spring was fairly congruent with the curve of ENM‐predicted suitability on this important niche‐determining variable. ENM‐based projections revealed that the southernmost populations were vulnerable under climate warming. Main Conclusions: Results verified that ENM based on species occurrences can well‐predict plant performance under field conditions. Congruence teaches us that with the climate change so far, the species exhibits a colonisation deficit in the north. Furthermore, the southernmost populations are vulnerable to extinction. A likely outcome is the shrinking of the species' range. [ABSTRACT FROM AUTHOR]

The warm edges of species' distributions are vulnerable to global warming. Evidence is the recent range retraction from there found in many species. It is unclear why populations cannot easily adapt to warmer, drier, or combined hot and dry conditions and locally persist. Here, we assessed the ability to adapt to these stressors in the temperate species Arabidopsis lyrata. We grew plants from replicate seed families of a central population with high genetic diversity under a temperature and precipitation regime typical of the low-latitude margin or under hotter and/or drier conditions within naturally occurring amplitudes. We then estimated genetic variance–covariance (G-) matrices of traits depicting growth and allocation as well as selection vectors to compare the predicted adaptation potential under the different climate-stress regimes. We found that the sum of genetic variances and genetic correlations were not significantly different under stress as compared to benign conditions. However, under drought and heat drought, the predicted ability to adapt was severely constrained due to strong selection and selection pointing in a direction with less multivariate genetic variation. The much-reduced ability to adapt to dry and hot-dry conditions is likely to reduce the persistence of populations at the low-latitude margin of the species' distribution and contribute to the local extinction of the species under further warming. [ABSTRACT FROM AUTHOR]