Zingel Quarry Problem Species Control

On behalf of the Swiss Gravel and Concrete Industry Association (FSKB), various neophytes and other problem plants were combated in several passes in different gravel pits and quarries throughout Switzerland.

In the Zingel quarry near Stansstad, it is primarily the butterfly bush ( Buddleja davidii ) and the Japanese knotweed ( Reynoutria japonica ) that need to be controlled. The work in the quarry has created open ruderal areas in which the neophytes have been able to spread undisturbed for years. The areas are quite large, in some places completely overgrown and also difficult to access.

In order to even get to the neophytes, we had to gain access with a brush cutter. The buddleia was already huge and the effort of digging up the roots was considered disproportionately great. In addition, due to the topography, there was no access for larger machines. It was therefore decided to saw off the woody parts of the plant and to treat the cut surfaces of the stalks with dry ice (solid carbon dioxide [-78°C]) as an experiment.

It was the first year in which attempts were made to combat neophytes with dry ice - so there is no experience in this regard. It will not be clear until early 2020 whether this method was successful. The production of dry ice is quite energy-intensive. Transporting it to the site of use must be well coordinated.