The power of water and new species

"Neophytes" , "neozoa" and "neomycetes"

Audioguide

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Regulated by subterranean structures, the power of water constantly brings forth new landscape forms. Thus the variety of landscapes in Carinthia did not come about by chance but is the result of geological processes that are still ongoing.

Since the beginning of the early modern era, human mobility has increased the immigration of new species to Europe: neophytes (new plants), neozoa (new animals) and neomycetes (new fungi). Certain new arrivals such as the Asian bush mosquito are invasive species that alter ecological systems and also harbour the threat of disease.

Mountains and rivers

Carinthia’s landscapes reflect its geology: the mountains are the result of converging continental fragments, and where there is a crack in the earth’s crust water will find its way and the wind will blow through until a valley is formed. Run-off from the mountains collects in the middle of the valley and becomes a running body of water. The course of the river network in its turn is regulated by extensive paths of movement underground (geological faults), reflecting this on the surface.

When several faults border all sides of a region, large, bowl-shaped depressions such as the Klagenfurt Basin can form, surrounded on more than two sides by mountains.

Valleys and lakes

Later on natural forces in the last ice age formed gentle or rugged terrain, depending on the subsurface. Glaciers ploughed narrow V-shaped valleys into broad U-shaped valleys, leaving their traces everywhere. After the ice melted, the valleys and large basins filled up with sand and gravel. In scoured-out rock basins and other ice-age hollows such as kettle holes meltwater collected, forming lakes. Beyond where the glaciers terminated in eastern Carinthia there are today no natural lakes.

Basement rock and limestone Alps

The river Drau flows right across Carinthia from west to east, following several geological faults that bar a few exceptions divide the bedrock (crystalline basement) in the north from the Limestone Alps in the south. The upper Drau Valley is a typical U-shaped valley, the basement rock of which was ploughed deep into the subsurface by the glacier. The present surface of the valley was later partly filled up with gravel and sand, and as a result now lies several hundred metres higher.

Ice-age legacy

During the ice age glaciers scoured out a row of three basins in the crystalline schist. The areas between the basins are visible on the surface in the peninsulas of Maria Wörth and Pörtschach. When the glacier melted, a river flowing from the north raised a large alluvial fan against which the water accumulated, creating Lake Wörth. The city of Klagenfurt was later built on the alluvial fan.

Striking height

The striking Hochobir peak is the tallest summit of the Northern Karavanks, owing to the fact that its massive Wetterstein limestone is surrounded by faults and softer, more readily weathered rocks. To its south runs the Periadriatic Seam, a fault zone that dominates the landscape and divides the Northern from the Southern Karavanks.

Asian invader

The Asian bush mosquito was introduced into large parts of North America and Europe through international trade. This invasive species is resilient enough to be able to survive the cold winters here. In its natural habitat it occurs mostly in forested areas or on their margins, laying its eggs in pools, puddles and other damp sites. Active during the day, the mosquito plagues humans and is a potential vector for viruses (for example the chikungunya virus) that can cause harmful illnesses in humans. The Kärnten Museum is playing an active part in monitoring programmes to ascertain the prevalence of the mosquito in the individual federal states of Austria.

Furry North Americans

Native to North America, the raccoon was introduced into Europe in the last century as a breeding animal in commercial fur farms. Individual specimens escaped regularly from these farms and as neozoa – new arrivals among the animal population – spread widely across Europe. A nocturnal omnivore, it gives birth to its young in the seclusion of hollow trees. Its defining characteristic is the black ‘mask’, a broad, dark strip of hair across the face and eyes. In Carinthia there are currently only very sporadic sightings of raccoons.

The return of the beaver

The beaver is Austria’s largest native rodent and in previous centuries was hunted extensively for its fur, meat, fat and other sought-after body parts. Now starting to return, they build their burrows, called lodges, out of timber at the edge of bodies of water. The entrance is always underwater.

At dusk and during the night they forage for plant-based food, felling even quite substantial trees to get at the nutritious buds and the bark. While the presence of beavers promotes biodiversity, their habits regularly bring them into conflict with humans.

Change through new plants

Since the ‘discovery’ of America by Columbus in 1492 the world has gradually moved closer together. Increased human mobility intensified the immigration of new types of organisms in our region as in many others. Some of these species are proliferating so rapidly that they are changing the native landscape to a significant degree. In Carinthia, these include the robinia, tree of heaven, Japanese knotweed and Himalayan balsam.

Resilient new arrival

Native to China, the tree of heaven came to Europe in the eighteenth century as an ornamental plant and is thus one of the ‘neophytes’ or new arrivals among our native flora. Rapid growth and an extraordinary ability to regenerate and adapt to a variety of conditions make it a resilient tree for urban contexts. However, its propensity for seeding in cracks in rocks and walls can cause massive structural damage. Cutting them back frequently results in growth from the stump and increased girth.