Biogeography

Ecological Diversity within Rear-Edge: A Case Study from Mediterranean Quercus pyrenaica Willd.

Understanding the ecology of populations located in the rear edge of their distribution is key to assessing the response of the species to changing environmental conditions. Here, we focus on rear-edge populations of Quercus pyrenaica in Sierra Nevada (southern Iberian Peninsula) to analyze their ecological and floristic diversity. We perform multivariate analyses using high-resolution environmental information and forest inventories to determine how environmental variables differ among oak populations, and to identify population groups based on environmental and floristic composition.

Late-spring frost risk between 1959 and 2017 decreased in North America but increased in Europe and Asia

Frost in late spring causes severe ecosystem damage in temperate and boreal regions. We here analyze late-spring frost occurrences between 1959 and 2017 and woody species’ resistance strategies to forecast forest vulnerability under climate change. Leaf-out phenology and leaf-freezing resistance data come from up to 1,500 species cultivated in common gardens. The greatest increase in leaf-damaging spring frost has occurred in Europe and East Asia, where species are more vulnerable to spring frost than in North America. The data imply that 35 and 26% of Europe’s and Asia’s forests are increasingly threatened by frost damage, while this is only true for 10% of North America. Phenological strategies that helped trees tolerate past frost frequencies will thus be increasingly mismatched to future conditions.

Potential changes in the distribution of Carnegiea gigantea under future scenarios

The goals of this study are to provide a map of actual habitat suitability (1), describe the relationships between abiotic predictors and the saguaro distribution at regional extents (2), and describe the potential effect of climate change on the spatial distribution of the saguaro (3).

Past and potential future population dynamics of three grouse species using ecological and whole genome coalescent modeling

Here we investigated the demographic history of the willow grouse (Lagopus lagopus), rock ptarmigan (Lagopus muta), and black grouse (Tetrao tetrix) through the Late Pleistocene using two complementary methods and whole genome data. Species distribution modeling (SDM) allowed us to estimate the total range size during the Last Interglacial (LIG) and Last Glacial Maximum (LGM) as well as to indicate potential population subdivisions.

Phylogenetic age differences in tree assemblages across the Northern Hemisphere increase with long-term climate stability in unstable regions

Our results show that phylogenetically diverse assemblages with large phylogenetic age differences among species are associated with relatively high long‐term climate stability, with intra‐regional links between long‐term climate variability and phylogenetic composition especially strong in the more unstable regions. These findings point to future climate change as a key risk to the preservation of the phylogenetically diverse assemblages in regions characterized by relatively high paleoclimate stability, with China as a key example.

Historical anthropogenic footprints in the distribution of threatened plants in China

In this study, for the first time, we linked the distribution of threatened species across China to current and historical changes in human population densities, cropland area, and pasture area since 1700 (at a 100 km × 100 km resolution). We find that variables describing historical changes in human impacts were consistently more strongly associated with proportions of threatened plants than variables describing current changes in human impacts. Notably, threatened plant species in China tend to be concentrated where historical anthropogenic impacts were relatively small, but anthropogenic activities have intensified relatively strongly since 1700.

The ecological niche and distribution of Neanderthals during the Last Interglacial

This paper [was highlighted in the *Editor's Picks* section of the Science Journal](https://www.dropbox.com/s/6k308eczv7i6kbj/2017_BMB_Journal_of_Biogeography_editors_choice.pdf?dl=1), and was among the [top downloaded articles](https://www.dropbox.com/s/sowq1h4bdngmipy/2017_BMB_Journal_of_Biogeography.png?dl=1) from the *Journal of Biogeography* during the 12 months after its publication.

Investigating Neanderthal dispersal above 55°N in Europe during the Last Interglacial Complex

Our results are inconsistent with the claim that climatic constraint and/or a lack of suitable habitats can fully explain the absence of Neanderthals in Southern Scandinavia during the Eemian Interglacial and Early Weichselian Glaciation. We do, however, find evidence that a geographic barrier may have impeded northerly migrations during the Eemian.

Spring predictability explains different leaf‐out strategies in the woody floras of North America, Europe and East Asia

Intuitively, interannual spring temperature variability (STV) should influence the leaf‐out strategies of temperate zone woody species, with high winter chilling requirements in species from regions where spring warming varies greatly among years. We tested this hypothesis using experiments in 215 species and leaf‐out monitoring in 1585 species from East Asia (EA), Europe (EU) and North America (NA). The results reveal that species from regions with high STV indeed have higher winter chilling requirements, and, when grown under the same conditions, leaf out later than related species from regions with lower STV. Since 1900, STV has been consistently higher in NA than in EU and EA, and under experimentally short winter conditions NA species required 84% more spring warming for bud break, EU ones 49% and EA ones only 1%. These previously unknown continental‐scale differences in phenological strategies underscore the need for considering regional climate histories in global change models.

Day length unlikely to constrain climate-driven shifts in leaf-out times of northern woody plants

Our results do not support previous ideas about phenological strategies in temperate woody species (the ‘high temperature variability’ hypothesis; the ‘oceanic climate’ hypothesis; the ‘high latitude’ hypothesis). In regions with long winters, trees appear to rely on cues other than day length, such as winter chilling and spring warming. By contrast, in regions with short winters, some species—mostly from lineages with a warm-temperate or subtropical background, for example, Fagus additionally rely on photoperiodism. Therefore, photoperiod may be expected to constrain climate-driven shifts in spring leaf unfolding only at lower latitudes.