Forest migration northward. Though "Fagus" and "Picea" populations did not expand directionally, they have grown in the Scandinavian range. The movement of "Picea" species in the past 1000 years has shown a strong connection to climate change through a model comparison. In the more recent past, there has been documentation of elevation shifts in distribution of many core forest tree species of Catalonia. The populations of two tree species (European Beech, "Fagus sylvatica"; and Holm Oak, "Quercus ilex") were evaluated in their dynamics over elevations through time. Generally, Holm Oak reside lower on mountain slopes than does European Beech. In the past
Stigmella hemargyrella Stigmella hemargyrella Stigmella hemargyrella is a moth of the Nepticulidae family. It is found in most of Europe, except Iceland, Norway, Finland, Portugal and most of the Baltic region. The moths (imago) are bivoltine flying from April to May and again from July to August and can be found resting on trunks. The wingspan is 5–6 mm. The egg can be laid on either side of the leaf and the pale yellowish-white larva feed, within a mine on "Fagus sylvatica" and "Fagus sylvatica orientalis". The mine is a sinuous gallery and at the early state is relatively narrow with a