Journal Article
Local temperatures inferred from plant communities suggest strong spatial buffering of climate warming across N orthern E urope
Jonathan Lenoir; Bente Jessen Graae; Per Arild Aarrestad; Inger Greve Alsos; W. Scott Armbruster; Gunnar Austrheim; Claes Bergendorff; H. John B. Birks; Kari Anne Bråthen; Jörg Brunet; Hans Henrik Bruun; Carl Johan Dahlberg; Guillaume Decocq; Martin Diekmann; Mats Dynesius; Rasmus Ejrnæs; John‐Arvid Grytnes; Kristoffer Hylander; Kari Klanderud; Miska Luoto; Ann Milbau; Mari Moora; Bettina Nygaard; Arvid Odland; Virve Tuulia Ravolainen; Stefanie Reinhardt; Sylvi Marlen Sandvik; Fride Høistad Schei; James David Mervyn Speed; Liv Unn Tveraabak; Vigdis Vandvik; Liv Guri Velle; Risto Virtanen; Martin Zobel; Jens‐Christian Svenning
Global Change Biology · Vol. 19, Issue 5 · pp. 1470-1481 · 2013
Abstract
Recent studies from mountainous areas of small spatial extent ( 2 ) suggest that fine‐grained thermal variability over tens or hundreds of metres exceeds much of the climate warming expected for the coming decades. Such variability in temperature provides buffering to mitigate climate‐change impacts. Is this local spatial buffering restricted to topographically complex terrains? To answer this, we here study fine‐grained thermal variability across a 2500‐km wide latitudinal gradient in N orthern E urope encompassing a large array of topographic complexities. We first combined plant community data, E llenberg temperature indicator values, locally measured temperatures (LmT) and globally interpolated temperatures (GiT) in a modelling framework to infer biologically relevant temperature conditions from plant assemblages within 2 units (community‐inferred temperatures: CiT). We then assessed: (1) CiT range (thermal variability) within 1‐km 2 units; (2) the relationship between CiT range and topographically and geographically derived predictors at 1‐km resolution; and (3) whether spatial turnover in CiT is greater than spatial turnover in GiT within 100‐km 2 units. E llenberg temperature indicator values in combination with plant assemblages explained 46–72% of variation in LmT and 92–96% of variation in GiT during the growing season ( J une, J uly, A ugust). Growing‐season CiT range within 1‐km 2 units peaked at 60–65°N and increased with terrain roughness, averaging 1.97 °C ( SD = 0.84 °C) and 2.68 °C ( SD = 1.26 °C) within the flattest and roughest units respectively. Complex interactions between topography‐related variables and latitude explained 35% of variation in growing‐season CiT range when accounting for sampling effort and residual spatial autocorrelation. Spatial turnover in growing‐season CiT within 100‐km 2 units was, on average, 1.8 times greater (0.32 °C km −1 ) than spatial turnover in growing‐season GiT (0.18 °C km −1 ). We conclude that thermal variability within 1‐km 2 units strongly increases local spatial buffering of future climate warming across N orthern E urope, even in the flattest terrains.