Why do taiga forests grow farther north in western Europe than along eastern continental coasts?

The distribution of taiga is primarily determined by the warmth of the growing season and temperature extremes, rather than a strictly east-west axis.1

In western Europe, the taiga reaches its northernmost extent—typically between 60° and 70° N—due to the warming influence of the Gulf Stream. This current, along with the North Atlantic Drift, transports warm, saline water into high latitudes, significantly moderating the climate of northwestern Europe.12

Conversely, along the eastern margins of continents, the taiga is deflected southward to between 50° and 60° N. This shift occurs because cold polar air masses flow southward along these eastern coasts, creating harsher environmental conditions that limit the northward expansion of the boreal forest.1