Targeting neophytes: Are invasive plants threatening our biodiversity?

Targeting neophytes: Are invasive plants threatening our biodiversity?

In Europe, over 16,000 vascular plant species have established themselves in foreign countries, such as the University of Konstanz reported. The majority of these plants, also known as neophytes, have established themselves in regions heavily influenced by human activity since the 1950s. Areas where human activities significantly alter natural habitats are particularly affected.

This naturalization has significant impacts on ecosystems. Invasive plants spread quickly and displace native flora. In a comprehensive study, an international research group examined the spread of 3,920 native plant species in ten European countries. She found that many of these plant species that establish themselves in foreign ecosystems are also widespread in their homeland.

The characteristics of successful neophytes

Successful species share common characteristics: they are often large, ecologically diverse generalists, competitive, and prefer nutrient-rich habitats. The study also shows that plants with declining abundance in their native area are rarely successful in establishing themselves in new areas. Common species are transported more frequently, increasing the likelihood of their establishment in foreign regions. This suggests that monitoring distribution in native habitats can provide important information about the chances of colonization in new areas.

There are particularly drastic examples of the effects of invasive neophytes in Germany and Switzerland. This includes the narrow-leaved waterweed, which has been widespread in Europe since the late 1970s CONVENTION describes. This aquatic plant originally comes from North America and has spread rapidly through targeted releases, shipping routes and water birds. Their massive occurrence leads to impenetrable underwater forests and displaces native aquatic plants, which particularly affects the pondweed and clamshell algae communities.

The waterweed is particularly competitive because it can cope with low temperatures and little light, which further promotes its spread. The eutrophication of the affected waters poses a further problem: dead biomass decomposes in autumn, which means that additional nutrients enter the water and further stimulate the growth of waterweed.

The challenges posed by invasive neophytes

The problems caused by invasive neophytes are diverse. They not only pose a threat to biodiversity, but also cause economic and health difficulties. The Botanica Suisse highlights that invasive neophytes often live without natural enemies, which promotes their spread. Their rapid reproduction and high regenerative ability make control measures difficult.

There are approximately 2,600 native plant species in Switzerland, of which over 600 are considered neophytes, with 58 classified as invasive or potentially invasive. One of the problematic neophytes is, for example, the multi-leaved lupine, which was introduced to Europe from North America 200 years ago. The legal framework for dealing with such species is also regulated: Since 2008, the reproduction, release and trade of certain invasive species have been prohibited in Switzerland.

To combat the spread of invasive neophytes, preventive measures such as the use of native plants and proper disposal are crucial. Monitoring the population development of invasive species is necessary in order to be able to intervene in a timely manner. Cantonal nature conservation offices and Info Flora offer support and information to effectively meet the challenge of invasive neophytes.