The tree line in the Engadin used to be significantly higher. In order to create more pastures, the forest was felled at the higher altitudes. Nowadays, the timberline is about 2000 m a.s.l. The village of Pontresina lies within the mixed vegetation zone of spruce and stone pine forest and larch forest. This line is determined by the cold winter nights. If the temperature drops below -30°C, the spruces suffer frost damage. The larch and stone pine are less susceptible to such cold winter nights. In October, Engadin’s forests are transformed into brilliant golden colours, giving autumn a very special touch.
A stone pine can be up to 30 m high and 1000 years old. Healthy stone pines keep their needles for about 5 to 7 years. The crowns are dense and impenetrable. Young trees tend to have more conical needles, whereas older ones have more rounded ones.
A larch can grow up to 50 m high and have a trunk diameter of as much as 1.5 m. The slim, conical crown typical of young trees becomes broader or flatter with age. The branches protruding horizontally from the usually straight, continuous trunk hang loosely and look almost lively. The larch is deciduous and turns golden yellow in autumn before dropping its needles. It is the only member of its species (Pinacea) to do so.