Data for: Traits help explain species’ performance away from their climate niche centre

Aim: Climate change impacts on biota are variable across sites, among
species, and throughout individual species' ranges. Niche theory
predicts that population performance should decline as site climate
becomes increasingly different from the species’ climate niche centre,
though studies find significant variation from these predictions. Here, we
propose that predictions about climate responses can be improved by
incorporating species' trait information. Location: Europe Methods:
We used observations of plant species abundance change over time to assess
variation in climate difference sensitivity (CDS), defined as how species
performance (colonization, extinction, and abundance change) relates to
the difference of site climate from the mean temperature and precipitation
of each species’ range. We then investigated if leaf economics, plant
size, and seed mass traits were associated with the species’ climate
difference sensitivity.   Results: Species that performed better
(e.g., increased in abundance) towards sites progressively cooler than
their niche centre were shorter and had more resource-acquisitive leaves
(i.e., lower leaf dry matter content or LDMC) relative to species with
zero or the opposite pattern of temperature difference sensitivity. This
result supports the hypothesis that if sites cooler than niche centre are
more stressful for a species, then shorter stature is advantageous
compared to taller species. The LDMC result suggests the environment
selects for more resource-acquisitive leaf strategies towards relatively
cooler climates with shorter growing seasons, counter to expectations that
conservative strategies would be favoured in such environments. We found
few consistent relationships between precipitation difference
sensitivities and traits. Main conclusions: The results supported key a
priori foundations on how trait-based plant strategies dictate species
responses to climate variation away from their niche centre. Further,
plant height emerged as the most consistent trait that varied with species
climate difference sensitivity, suggesting height will be key for theory
development around species response to climate change.