Taisha is the author of this entry. She writes:
Today, we have a photo of Pinus sylvestris, commonly known as Scots pine, showing the needles and male cones (microstrobili). The image is courtesy of Marianne (aka marcella 2/tovje@Flickr, and was shared via the Botany Photo of the Day Flickr Pool. The Flickr pool has another image of the species in habit by Stephen Buchan (aka –Green Light Images–@Flickr). Thank you both for sharing!
Pinus sylvestris is the second-most widely distributed conifer in the world (exceeded only by Juniperus communis), with a native range spanning beyond the Arctic Circle to southern Spain, and from western Scotland to eastern Siberia. The species grows at elevations from sea level to 2400 meters (~8000 ft.).
The last major episode of widespread glaciation, about 10 000 years before present, occurred during the Pleistocene. During this time, many plant species survived in small isolated ice-free areas known as glacial refugia. For Scots pine, evidence so far suggests the species survived in four main refugia as well as an area south of glacial extent (the Russian Plains). The four refugia were: 1) the Iberian Peninsula, 2) the northern Apennine Peninsula, 3) south of the Carpathian and Sudeten Mountains, and 4) the Balkans. As the glaciers retreated, Pinus sylvestris recolonized Europe. However, it is still unclear which routes and specific refugial populations had the most prominent roles.
In a study by Prus-Glowacki, et al., some suggestions about the recolonization patterns of the Scots pine after the last glaciation are made. They propose that the Iberian and Apennine Peninsulas populations either did not at all, or only slightly contributed to recolonization. Furthermore, they state that the Balkan refugium contributed as a source area for Scots pine migration into central and western Europe, while those ancestral populations from eastern Europe and Siberia primarily contributed to the present gene pools in central Europe and Scotland. Lastly, the researchers note that the origin of the Scottish populations is unclear, as they form a distinctly separate group derived from more than one glacial refugium after the last glaciation (see: Prus-Glowacki, et al. (2012). Genetic variation of isolated and peripheral populations of Pinus sylvestris (L.) from glacial refugia. Flora– Morphology, Distribution, Functional Ecology of Plants. 207(2):150-158).
In a previous BPotD entry from 2011 about Loch Maree, Scotland, Daniel mentions Pinus sylvestris and briefly touches on the biogeography of this species, with particular attention to its presence in the Loch Maree area.