The Confederation wants to promote and improve biodiversity along the motorway. Four years ago, it launched a pilot project in French-speaking Switzerland to delimit more lively and varied green zones. The authorities draw an encouraging initial assessment.
Some motorists may have noticed that the grassy areas along the French-speaking motorways are no longer mowed as often as usual. In some areas, grasses grow in abundance and the grass is tall. More difficult is however to see the small white panel with a blue flower in the middle fixed on a green and white stake.
This new signage is mainly used by road maintenance personnel to carry out differentiated maintenance of the edges of highways. This is one of the main objectives of the Federal Roads Office (FEDRO): to slow down the loss of biodiversity and the disappearance of fauna and flora as well as to fight against invasive plants in these places stuck to the bitumen.
“Colossal green heritage”
“There is life in there and it must be preserved”, summarized Wednesday in Lausanne Erwin Egger, project manager, biodiversity and green areas referent at the Intercantonal Motorway Network Maintenance Service (SIERA) for Vaud, Geneva and Freiburg. A network that extends over 302 km, with therefore some 600 km of green spaces.
“It’s a colossal ecological heritage. The highway is not just a bituminous cordon”, he underlines.
Since the launch in 2012 of the Swiss Biodiversity Strategy, a team of biologists toured the national highways in 2014 to determine the best possible areas to promote this biodiversity. For questions in particular of resources, it is finally in French-speaking Switzerland that the pilot project aiming to make the inventory and the analysis of the precise sectors to delimit then the test of new practices of mowing is launched.
A quarter in a biodiversity zone
“Today in French-speaking Switzerland, around a quarter of all green spaces along motorways have biodiversity potential. For Vaud, Geneva and Fribourg, this even represents some 166 hectares out of a total of 500 hectares, i.e. a third “, says Mr. Egger. The Confederation requires a minimum of 20%.
“The new approach consists of mowing late, as little as possible and leaving at least ten centimeters, no longer crushing the grass, no longer leaving the cut in place in order to avoid over-enriching the soil, keeping 10% of area refuge at each mowing to preserve the life cycle of fauna and flora, and to fight against invasive species, whether native or exotic”, lists the project manager.
No more systematic mowing and chemicals. This differentiated upkeep and this selective collection involves new reflexes, sometimes even uprooting by hand. “Above all, it is necessary to train staff to be more curious and attentive to biodiversity, to recognize invasive plants, while investing in new generation multifunction machines, light, self-supporting or even with lateral reach”, explains Mr. Egger.
Ambrosia and Cape Ragwort
Regarding the proliferation of these “invaders”, he cites thistle, ragweed (very allergenic) and Cape groundsel. A cousin of the tansy ragwort, the latter is 100 times more invasive. Arrived in the past in our regions from South Africa, via the wool trade, it is toxic for cattle and horses. They come at an economic cost to public health and agriculture, he says.
To curb their spread, for example, it is necessary to systematically and meticulously clean the machines and vehicles used, because they easily stick to chassis or tires. A cut 10 cm high, instead of mowing at ground level, plunges these neophytes into the shade and the lack of sun prevents their conquest. Another long-term hope: an aphid coming up from Spain and attacking certain invasive plants.
Monitoring every five years
FEDRO, which is working in partnership with SIERA for this pilot project, financed the entire phase of inventory and analysis of the zones as well as the testing of the new machines, initially rented. The amount is approximately one million francs. SIERA then takes care of the purchase of vehicles and training.
The two partners drew positive and encouraging conclusions from this pioneering approach in Romandie. “We are seeing the return of nesting birds, new insects and more varied vegetation.” says Mr. Egger. All demarcated biodiversity areas will be monitored by independent bodies every five years, he added.
This article has been published automatically. Source: ats