Interview with Julia Fürst, a biology student in the field of biodiversity and conservation biology
Reminder: the following information applies to the Zurich area, Switzerland
Is every exotic plant automatically a neophyte, i.e. invasive?
"No, one in ten plants is non-native, one in 100 plants is a neophyte."
What are the requirements for a non-native plant species to be considered a neophyte?
"They survive the winter, can reproduce independently, multiply explosively, are harmful to the native fauna, flora and also to humans. Unfortunately, economic damage is the main contributor".
Are there tree species among them?
"Yes, even the 4th most common tree species in the city of Zurich is a neophyte, the Robinia. The Robinia is no longer planted by the city, and is gradually being replaced by native trees. In the case of private construction sites, their planting is also no longer permitted. There are also many others."
Which tree species are particularly affected by neophytes?
" Hardwood trees are affected because hardwoods grow rather slowly. The fast-growing neophytes displace them like this."
What effects can neophytes have on the environment?
"As already mentioned, the native trees are being displaced. The nutrient composition of the soil is changed, which further weakens the native plants. The general soil moisture also decreases, because fast-growing neophytes transpire water much faster. Surrounding plants are no longer competitive and die off".
Is there a difference between rural and urban areas?
"In the city, there are fewer problems because the neophytes have less chance of spreading at all. The city offers little open ground, they can often only spread in cracks on the asphalt and concrete. Neophytes are rarely found in green spaces such as parks, because these areas are often maintained.
In the countryside, and especially in forests, the situation looks more dramatic. In the forest, neophytes are not frequently monitored, so they can spread unhindered and are usually discovered late. This makes their containment more difficult. In such a case, the control can take years".
What if I planted a plant years ago and it is now a neophyte?
"The obligation to report applies. Their control is not at the expense of the owner or the nursery that sold the plant. The municipality or canton is responsible for the control. Flowering parts of the plant, seeds and fruits should be disposed of in a waste incineration plant or transported directly to a composting plant. The storage of plant parts is prohibited".