Neophytes are plant immigrants. They spread where they were otherwise not native and establish themselves in their new location. The spread of neophytes often happens unintentionally by humans. Neophytes arrive in foreign areas as stowaways due to the global movement of goods.
What are neophytes? Meaning, characteristics, explanation, definition
Plants that have been native to us for a long time, but nevertheless came to us in the Neolithic Age or through the trade of the Romans, are called archaeophytes. This includes, for example, the sweet chestnut.
New plant species are not that unusual in our plant world. Most of our plant species arrived in Central Europe after the Ice Age. In addition to the chestnut, people also brought many arable wild herbs with regard to agriculture and cereals, some of which are still on the Red List today. The Central European plant kingdom is characterized by non-native plant species.
As a result of the increasing international movement of people and goods, and especially after the discovery of America, many alien plant species have spread here. Only half of the neophytes living in our country were intentionally introduced. About 30% of the neophytes are purely ornamental plants and the remaining 20% exist as forestry and agricultural crops, such as the corn, the potato or the tomato. The other half of the introduced neophytes succeeded unintentionally and was in most cases an unwanted admixture of the seeds.
Do neophytes pose a danger?
At only 0.2%, the proportion of alien neophytes is relatively small. Species such as Japanese knotweed and Indian knapweed are considered to be of ecological concern. These plants can form very dense stands and crowd out native plant species. For humans, species such as giant hogweed and mugwort also pose health risks. Pigeonweed in particular can be a nuisance for allergy sufferers, as it forms aggressive pollen. Even people who have not previously reacted to flower pollen can develop allergic reactions as a result. Symptoms such as rhinitis, asthma, shortness of breath or burning eyes are then no longer uncommon.
If one comes into contact with the sap of the giant hogweed, this can increase the photosensitivity of the skin. Even a weak exposure to sunlight can cause painful blisters and redness on the skin. Counteracting such potential danger is a difficult task. Already established neophytes are difficult to eliminate. Nevertheless, local nature conservation associations make efforts with various regular actions to eliminate these pests either by digging them up or mowing them down. Should one locate pigeon weed or giant hogweed in one’s own environment, they should be eliminated. The best way to do this is to dig them out, including the roots, with a deep spade cut, even before they begin to bloom. Since there is a risk of burns, never work without long-sleeved clothing or gloves.
Pigeon weed can also be encountered while out for a walk. The plant should then best be pulled out immediately. Direct skin contact should also be avoided. If larger populations are discovered, it is best to inform the responsible municipality so that it can initiate further measures.
If you are on vacation in a foreign country, you should never take seeds or plants with you that you do not know. Moreover, in most countries the export of plants is prohibited anyway. Moreover, the impact of foreign species on native species cannot be estimated far enough.
One plant species that is spread, especially through bird feeders, is the mugwort ambrosia. Its pollen can cause severe allergies in humans. Currently, there is a rather strong spread of this neophyte in Bavaria. In order to put a stop to this plant species, the Bavarian Ministry of the Environment has initiated the campaign „Ambrosia Control in Bavaria“.
Advantages: What positive effects can neophytes have?
However, some neophytes can also be beneficial to an existing ecosystem. For example, new food webs can develop between newly established and native plant species. For example, summer lilac from China is home to approximately 11 caterpillar species and 43 butterflies. Summer lilac can also provide a good food source for insects primarily in summer. Even in late spring, when the native flora has almost no flowers left, the giant perennial still provides a plentiful source of food. The invasive horse chestnut, as well as the accompanying larvae of the horse chestnut leaf miner, can provide an important food source for native great tits or blue tits for their young birds.
What else goes along with invasive neophytes?
Invasive neophytes are when plant species establish themselves in areas where they were not previously native and cause problems there. For example, alien plants can cause the following problems:
- Maintenance costs of water bodies and roads may be higher
- Biodiversity decreases due to displacement of native fauna and flora
- There may be adverse health effects
- Forestry and agriculture suffer a financial loss
- Structures can be damaged
- Decrease in value, for example in land prices
Conclusion: Not all neophytes are bad
One should always keep in mind that only a few non-native plants disturb the native ecosystem. And even fewer of these species are a health hazard. While many native species became extinct during the Ice Age, there is still plenty of ecological room for new species. The resilience of the Central European ecosystem has become very robust to immigrants in plant and animal life over the course of the ice ages. New species can often establish themselves in our ecosystem without further negative consequences. Already about 10,000 years ago, new species migrated to Central Europe. This phenomenon is also intensified by climate change. Already due to global warming it can be assumed that the distribution areas of many species may shift decisively. Therefore, nature conservation will have to pay more attention to the numerous immigrants in the future. Such species, which were already native to Central Europe during the ice ages, should also be tolerated by us today.