Changes in distribution of Ilex aquifolium

Reanalysis of both biogeographic and bioclimatic data of equal spatiotemporal resolution, covering a time span of more than 50 years.   In this paper, we compare both detailed historic climatic and biogeographic records with updates of the same parameters at the same localities in the northern fringe area of the distribution of Ilex aquifolium, applying the same methodology as used in the original study ( Iversen 1944 ). We also compare our field data to predictions from simulations of Ilex distributions using a purely climate-driven bioclimatic model. Our aim is, therefore, to verify whether a potential shift in the local and regional distribution of a species is in synchrony with concurrent changes in climatic data on the same spatio-temporal resolution. Mean temperature values for the warmest and coldest month for a subset of climate stations used by Iversen (1944) and updated for the period 1971 – 2000.