Pollen and lake-level data from Le Locle in the Swiss Jura were used to quantitatively reconstruct climatic parameters for the Younger Dryas event and the first half of the Holocene period. The Younger Dryas cold event at Le Locle was characterized by (i) a general trend toward a slight increase in summer temperature and a decrease in annual precipitation and (ii) a marked drying phase at ca. 11,900 cal yr B.P. that occurred between two wetter ones. Further phases of major deficit in moisture occured at ca. 11,500 cal yr B.P. (Younger Dryas-Holocene transition), 10,800 cal yr B.P., 8700 cal yr B.P., and 6500 cal yr B.P. Climatic parameters reconstructed here suggest that phases of higher lake level developing at ca. 12,500–12,000, 11,750–11,600, 11,200–10,900 (synchronous with the Preboreal oscillation), 10,400–8900, 8400–8300 (possibly related to the 8200 yr event), and 7800–7000 cal yr B.P. coincided with an increase in annual precipitation, a decrease in summer temperature, and a shorter growing season. Conversely, periods of low lake level corresponded to a decrease in annual precipitation, an increase in summer temperature, and a longer growing season. This general pattern could have resulted from alternate southward-northward displacements of the Atlantic Westerly Jet.

Few data are available and little is known about spatial variation in post-dispersal seed removal at different levels throughout the geographic range of a plant species. Here, we compare post-dispersal seed removal by rodents within and among sites in two distinct regions, the south-eastern Spanish Mediterranean highlands and the Swiss Jura. Seed removal was assessed experimentally for four fleshy-fruited species (Berberis vulgaris, Crataegus monogyna, Rosa spp. and Taxus baccata) in heterogeneous sites with distinct microhabitats. A factorial general linear model (GLM) analysis was used to evaluate the relative influence of species-specific seed traits on removal at three spatial levels (microhabitat, site and region). In both highland ecosystems, live trapping revealed that rodents were the main seed removers: Apodemus sylvaticus was observed in both regions, whereas A. flavicollis and Clethrionomys glareolus occurred only at the Swiss sites. There was a significant difference in seed removal between regions, and the preferences of the rodents varied among plant species and microhabitats. Variation in rodent presence explained some differences in seed removal between regions and among microhabitats. Finally, the effect of rodent presence on seed removal differs due to both regional and microhabitat effects.