Feb 20, 2023: The Opuntia species of cactus, sometimes known as prickly pears, have been spreading throughout Valais, invading on the area's natural reserves, and posing a threat to biodiversity, according to the authorities. Keep reading to know more!
The residents of the Swiss canton of Valais(a subdivision of southern Switzerland) are accustomed to seeing mountain sides covered in snow in the winter and in edelweiss blooms in the summer. Cacti, which are generally known to thrive in hot and dry climates, are however beginning to oddly colonise the slopes as global warming intensifies.
The Opuntia species of cactus, sometimes known as prickly pears, have been spreading throughout Valais, invading on the area's natural reserves, and posing a threat to biodiversity, according to the authorities.
The municipality of Fully in the Rhone valley declared in a press release announcing the uprooting campaign that "this invasive and non-native plant is not welcome in the perimeter of prairies and dry pastures of national importance."
The Rhone is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea.
The Rhone Valley is a key wine-producing region in the southeast of France. It follows the north–south course of the Rhone river for almost 240km (150 miles) from Lyon to the Rhone Delta on the Mediterranean coast.
At Sion, the capital of Valais, a few hills have also sprouted Opuntia species and related varieties of cacti. It is claimed that Opuntia plants currently make up 23–30% of the region's sparse vegetation.
Their expansion has also been noted in nearby Alpine regions, such as the Italian Aosta Valley and Valtellina as well as the Swiss Grisons and Ticino.
IT is estimated that cacti can take one-third of the accessible surface in some areas of Valais, according to biologist Yann Triponez, who works for the Valais canton's nature protection department.
According to him, Opuntia has been growing in Valais since it arrived from North America at least in the late 18th century.
But, according to the authorities, they have been growing in optimal climatic conditions due to the Alps' warmer climate, longer vegetative seasons, and decreased snow cover.
According to retired geology professor Peter Oliver Baumgartner, "These species bear -10C or -15C without any trouble."
Nonetheless, he continued by saying that these species prefer a dry environment and dislike snow cover.