Jostedalen

a brief summary of its nature history, revealed through scientific research by universities and government agencies.

10'000 years ago Norway was still covered by an ice sheet, a remnant of the last major ice age, which culminated 18'000 years ago. Then the climate improved, and deglaciation started. The glacial retreat left much evidence of the development of landscape, vegetation and animal life. Reconstruction of glacial and post glacial history has been carried out during the last century. Several kinds of scientists, both national and international, come to Jostedalen, strongly attracted by this magnificent eldorado of well developed, well shaped and so far mostly well preserved landscape forms.

The largest glacier in Northern Europe, Jostedalsbreen, 487 km² , covers the high mountain plateau northwest of Jostedalen. 22 named outlets - "glacial arms or tongues" - flow from the plateau glacier, 11 of these into the hanging valleys running more or less vertically to the main valley, Jostedalen. Hanging valleys are found on both sides and can be seen as bowl-shaped openings high up on the hillsides.

The most famous glacial outlets are Nigardsbreen, Bergsetbreen and Austdalsbreen. More than 30'000 tourists come to see Nigardsbreen each year. The well preserved moraine landscape in front of the glaciers, especially Nigardsbreen, tells us much about deglaciation history.

At Nigard there are many moraines which can be traces across the valley and up the hills on both sides. These have been dated by biochemical dating and found to be from the period called "the Little Ice Age" that culminated about 250 years ago. A detoriation in climatic conditions made the Jostedalen glacier grow, and the outlets surged forward or flowed down the valleys, damaging farms and vegetation, and people's livelihood. Although this was a natural disaster at the time, the event has been extremely useful to the scientists of today when studying the invasion of plants and animals onto virgin land.

The deglaciation history is also better understood thanks to these more recent forms. Very clear moraine landscapes were left, forming a very valuable documentation for scientists. The outmost moraine ridge is called the 1750 moraine, and tells us when "the Little Ice Age" culminated. Today, the Nigard valley, the Nigard glacier and some other special areas such as the Fåbergstølsgrandane are highly regarded, both as scientifically interesting areas as well as objects for environmental protection.

Fåbergstølsgrandane is a most iteresting area, composed of material from subglacial erosion, transported by the glacial rivers coming from Lodalsbreen and Stegholbreen glaciers, and spread out like a wide sandy fan as the river often alternates between several river channels. The phenomenon of the sandy fan is known as a "sandur"- an Icelandic expression. Fåbergstølsgrandane is the largest remaining active sandur on the European mainland.

The Sandur provides very instructive documentation as to how several landscape features are formed, and how plants and other kinds of life become established and survive under such extreme conditions.

Fåbergstølsgrandane is a strongly dynamic area with major ecological gradients. Pioneer plants and a primitive fauna live at the edge of the glacier, while more developed and diversified life has been established further down the sandur and throughout the main valley to the Sognefjorden.

Wildlife and vegetation

Although Jostedalen and the Jostedal glacier offer rugged conditions, an interesting variety of vegetation and animals have become established and developed during the last 8'000 - 9'000 years.

The present wildlife consists of many species, ranging from large animals such as the brown bear, elk, red deer, fox, hare and squirrel down to fresh water animals such as fish, mostly trout, as well as several kinds of insects and plankton.

Former species, both animals and vegetation, can be traced through some of the local varieties which have adjusted to harsh conditions in close vicinity to the glacial outlets. One of the insect genera, Vivacricotopus, has never been found anywhere else before, although a similar species has subsequently been found in northern Alaska.

In the mountainous areas around the reservoirs, and unusual vegetation community occurs. However, over the last 8'000 - 9'000 years, the main valley Jostedalen has been successfully forested by alder, birch and pine. Also several kinds of bushes, heathers, other flowering plants, ferns and mosses, have invaded the area as the glaciers retreated.

The birds of Jostedalen have also been studied. Some stay all winter, while others return from Africa and other warm, exotic places when Norway offers nordic summertime conditions, not too hot and with long hours of daylight. The highest density of bird species in western Norway has been recorded in certain parts of the Jostedalen area.