Cold, snowy, windy. When you hear
those words they make you think of mountains. The Alpine biome is like winter is
to people in New England; snow, high winds, ice, all the typical winter things.
In Latin the word for 'high mountain' is 'alpes'. That is where today's word
alpine comes from.
Alpine biomes are found in the
mountain regions all around the world. They are usually at an altitude of about
10,000 feet or more. The Alpine biome lies just below the snow line of a
mountain. As you go up a mountain, you will travel through many biomes. In the
North American Rocky Mountains you begin in a desert biome. As you climb you go
through a deciduous forest biome, grassland biome, steppe biome, and taiga biome
before you reach the cold Alpine biome.
In the summer average temperatures
range from 10 to 15° C . In the winter the temperatures are below freezing. The
winter season can last from October to May. The summer season may last from June
to September. The temperatures in the Alpine biome can also change from warm to
freezing in one day.
Because the severe climate of the
Alpine biome, plants and animals have developed adaptations to those conditions.
There are only about 200 species of Alpine plants. At high altitudes there is
very little CO2, which plants need to carry on photosynthesis. Because of the
cold and wind, most plants are small perennial groundcover plants which grow and
reproduce slowly. They protect themselves from the cold and wind by hugging the
ground. Taller plants or trees would soon get blown over and freeze. When plants
die they don't decompose very quickly because of the cold. This makes for poor
soil conditions. Most Alpine plants can grow in sandy and rocky soil. Plants
have also adapted to the dry conditions of the Alpine biome. Plant books and
catalogs warn you about over watering Alpine plants.
Alpine animals have to deal with two
types of problems: the cold and too much high UV wavelengths. This is because
there is less atmosphere to filter UV rays from the sun. There are only warm
blooded animals in the Alpine biome, although there are insects. Alpine animals
adapt to the cold by hibernating, migrating to lower, warmer areas, or
insulating their bodies with layers of fat. Animals will also tend to have
shorter legs, tails, and ears, in order to reduce heat loss. Alpine animals also
have larger lungs, more blood cells and hemoglobin because of the increase of
pressure and lack of oxygen at higher altitudes. This is also true for people
who have lived on mountains for a long time, like the Indians of the Andes
Mountains in South America and the Sherpas of the Himalayas in Asia.
bibliography:
"Himalayas", http://encarta.msn.com/find/, (June 2000).
"General Ecology, EEOB 404",
http://www.tulane.edu/~eeob/Courses/Ecology_Materials/arctic_alpine_99f.html, (June 2000).