Eurasian aspen

A keystone species of the forest

Eurasian aspen, photo the City of Helsinki materialbank, Jan W. Ahlfors

The Eurasian aspen (Populus tremula) grows in a wide variety of habitats. It is quick to grow in open areas by the seashore or at the edges of forests. Abandoned meadows typically develop into rustling aspen stands in just a few decades.

In humus soil, Eurasian aspens sometimes grow to gigantic proportions, by which time they are usually already surrounded by the spruce trees that eventually replace smaller aspens. The wood of aspen decays easily, which is why Phellinus tremulae and other polypores often grow on aspen trunks.

The larva of Saperda carcharias, which is considered a pest, lives inside the bases of Eurasian aspens. A partly decayed Eurasian aspen can stay alive for decades. It is these types of aspens that black woodpeckers and great spotted woodpeckers dig nest holes into.

The bark of the Eurasian aspen serves as food for bank voles and hares, and aspen leaves are eaten by flying squirrels. The Eurasian aspen is a keystone species in Finnish forests, meaning that they contribute to the living conditions of other species to such an extent that the forest ecosystem would collapse without them.

Eurasian aspen





















Photo Jussi Helimäki.