Switzerland's largest surviving marshland habitat is now a protected environment, but human visitors are more than welcome.

The vast majority of visitors to the Grande Cariçaie are feathered. Some are very rare. But a visitors' centre at Champ-Pittet, just outside Yverdon, run by the Swiss conservation group Pro Natura, allows people to better understand the value of this narrow, 40 kilometre stretch of marshes and woodland.

That value can be understood when one learns that in the last 100 years, 90 per cent of marshland in Switzerland has been lost, and that this sliver of land contains more than a quarter of all animal species and a third of plant species native to the country.

The Champ-Pittet centre, then, has a unique scientific and educational value, and groups of schoolchildren can often be seen treading the boardwalks through the marshes and reed beds, pointing at the coots, dragonflies and newts. The ecosystem here may be fragile, but a network of well-signed paths allows people to get close - but not too close - to nature.

Landscapes

Mainly through chance, la Grande Cariçaie has remained an unspoiled island of rich biodiversity in a heavily populated region. With Expo 02, Switzerland's national exhibition currently taking place on and around the lake, the contrast is even more striking.

"Everything is lovely about this area. The landscapes are wonderful, especially as the sun rises or sets. Some people love the landscape. Some come for the birds, others for the flowers. I think it should be seen in its entirety," says Benoît Renevey, deputy director of the Champ-Pittet centre, and author of a book about the Grande Cariçaie.

The Grande Cariçaie comprises seven nature reserves running along the southeastern side of Lake Neuchâtel, between Yverdon-les-Bains in the south and Cudrefin to the north.

"It's important that it's so big, because many species - like the bittern, for example - have a large territory and would not be able to live here if it were divided up into smaller portions," Renevey says.

At least 10,000 species - ranging from microscopic invertebrates to wild boar - can be found in these 4,500 hectares. There are 48 species of mammal, 15 species of amphibians and 48 different kinds of dragonfly. This incredible diversity is partly explained by the many different environments found in this narrow strip of land.

Important breeding ground

But if the animals and insects are abundant, the Grande Cariçaie is best known for its birds. Of the 300 species that can be found in these wetlands and wood, 200 nest here.

Indeed, it is the main breeding ground for many birds that have seen their natural habitat dwindle, not only in Switzerland, but throughout Europe. These include the Little Bittern, the Great Reed Warbler, Savi's Warbler and the bird that has become the symbol of the Grande Cariçaie and the Pro Natura Centre at Champ-Pittet, the Great Crested Grebe.

That the Grande Cariçaie is a crucial link in the continent's biodiversity chain is even more apparent in the winter, when the lake becomes a vital stopping off point for migratory birds - either those en route to somewhere else, or the 100,000 that spend their winters here.

"In December or January, you can see 30,000 ducks on the lake between Yvonand and Cheyres. It's a spectacular sight," Renevey says.

The nature trails at Champ-Pittet are free and open all year round. It is a privilege to be able to see birds, amphibians and insects up close and in such abundance, to be able, for example, to stand just a few metres from the Great Crested Grebes' nesting ground.

Recent arrivals

Many might assume that this unspoilt landscape has been like this for thousands of years. But in fact the Grande Cariçaie has only been in existence for little more than a century.

It was born as a result of what was known as the Correction of the Waters of the Jura. This diversion of the rivers of northwestern Switzerland was prompted by the frequent flooding suffered on the plains around the lakes of Neuchâtel, Murten and Biel. The area from Orbe to Solothurn was often transformed into a great swamp.

One of the effects of this correction was that the level of Lake Neuchatel fell by nearly three metres and a whole new wetland habitat was exposed: La Grande Cariçaie.

"This new marshland was colonised by the animals that were forced out of the old swamp areas," Renevey says. Unsuitable for agriculture, these areas were left largely untouched, save for isolated campsites. The fauna and flora were left to thrive unhindered.

It was not until the late 1970s, when the authorities planned to build a motorway through the marshes, that a campaign was launched to save them.

In winning legal protection last October from the authorities of Vaud and Fribourg - the two cantons in which the Grande Cariçaie falls - the marshes have been protected from the activities of humans. Swimming, boating and fishing are banned in certain places.

But the biggest threats to this priceless region come from nature itself: erosion and the advance of the forest.

As the lake points southwest to northeast, it is particularly affected by the Bise, the cold northeasterly wind that blows through Switzerland every winter. This inevitably causes turbulent waters that erode the banks, and the southern shore near Yverdon is especially exposed.

Pro Natura has decided to combat the forces of nature: "We have to intervene and take whatever measures we can to protect the marshlands that remain," Renevey says. A series of dykes and barriers are being built to calm the impact of the wind and waves.

In addition, it is natural for the grassy swampland to be gradually taken over by the forest, a process that would eventually result in the disappearance of the marsh - and almost certainly dozens of species of animals and plants. To prevent this, the vegetation along the lakeshore is mowed every three years.

by Roy Probert

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