In the Alps, as you travel up the mountain, plants change in height, growth form, colour and type of understorey. There are four distinct zones in the Alps including lowlands, montane, subalpine and alpine zones. Each zone includes various plant communities.
Grassy woodlands and dry open forest ecosystems can be found in the lowlands zone. Trees are well spaced and sunlight can easily reach the forest floor. The climate is relatively warm and it rarely snows in this zone.
In the montane zone forests becomes taller, wetter, darker and denser. Alpine Ash trees grow closely together and the understorey consists of ferns and small trees.
The subalpine zone can de found above 1500 metres. The tall trees change into a low-growing subalpine woodland consisting of Snow Gum trees with an understorey of grasses and herbs. Snow Gums have to cope with low temperatures, snow and ice.
In the alpine zone, you can see the most obvious change of vegetation. This is where the treeline occurs, above this line it is too cold for trees to grow and only shrubs and herbs occur. In this zone snow cover stays for more than four months of the year so plants are unable to photosynthesise all year round. Grasslands, herbfields, heathland and bogs can be found in this zone.
Variation within the zones
There are variations in plant communities within the zones depending on the soil, relief and location on the slope of the mountain.
The terrain of the Alps varies enormously, ranging from escarpments and deep gorges to rolling hilltops. The relief determines the soil type, for instance soils on hill tops are deep and loamy and support herbfields while soils on rocky ridges are shallow supporting shrubby heath lands.
The location on the mountain slopes determines how dry or moist it is. Conditions on south-east slopes are wetter than on the north-west slopes as these areas receive sun light in the early part of the day and temperatures stay moderate throughout the day. As the sun moves to the western slopes, the temperatures of the day reach their maximum, and any moisture on the slopes is quickly evaporated. In the alpine zone, the drier north-west slope also has to cope with winds that carry snow and ice.
Alpine ‘islands’ often have their own unique plant and animal species – such as the Baw Baw Frog. These ‘islands’ are formed through weathering of alpine mountain peaks over millions of years. Rivers have worn deep valleys forming extensive areas of montane slopes.