Neophytes are often portrayed as dangerous and hostile. But very few species have negative consequences for our ecosystems. These species characterize not only nature but also cultural landscapes. Accordingly, alternative ways of dealing with this potential danger are not entirely new.

The lupine was also introduced

Table of Contents

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  1. the essentials in brief
  2. Neophytes - definition
  3. Invasive neophytes - Germany
  4. Examples of neophytes
  5. Combat useful?
  6. frequently asked Questions

    7. the essentials in brief

    • Neophytes are plants that are not part of the natural vegetation of a habitat. They are carried around the world by humans, but plants have been spreading beyond their natural range since the Ice Age.
    • A few species are dangerous for the native flora. Such organisms are called invasive.
    • Some examples are attracting a great deal of attention because of their propensity to spread.
    • Using alternative methods, individuals can stop the spread of such species. Many new plants are edible.

    What are neophytes?

    Neophytes are a subcategory of Neobiota. This designation derives from the Greek terms néos for "new" and bíos for "life". In the strict definition, neobiota includes all species that have been distributed in the world by humans. These creatures are spreading into foreign territories where they were previously not considered native. Few naturalists are of the opinion that other species that spread into foreign areas without human intervention also fall under the neobiota.

    The term neobiota includes:

    • neophytes: neobiotic plants
    • Neozoa: neobiotic animals
    • neomycetes: neobiotic fungi

    A look into history

    So-called new plants are not an unknown phenomenon. It is a natural process that new species are constantly migrating to Central Europe. The entire vegetation of Central Europe is characterized by species that have immigrated since the Ice Age. The ecosystems in Germany and Europe have developed a high level of resilience to newly introduced species.

    There are many niche habitats where alien species find a place and thrive alongside native plants. This development is promoted by climate change, because due to global warming, heat-loving plants and animals are increasingly spreading to northern regions.

    Neophytes in Germany before and after 1492

    During the Neolithic period, people carried away numerous wild herbs when they brought in grain. Today, many of these herbs are on the Red List of Threatened Species. These plants, introduced to Europe by Neolithic humans or Roman trade, are called archaeophytes. Only since the discovery of America in 1492 by Columbus did the global movement of goods and people, and thus the transport of plants, increase. All plants introduced after this year are called neophytes.

    Current situation

    Almost half of all neophytes that have established themselves in Germany were introduced intentionally. Of this amount, 30 percent are ornamental plants. The remaining 20 percent are agricultural and forest crops such as corn, potatoes and tomatoes. The other half of the new plants were introduced unintentionally, for example as an unwanted admixture in the seed.

    When it makes sense to control alien species:

    • Remnants of endangered species are being pushed out
    • in the case of risks of hybrid formation between non-native and native species
    • historical authenticity of species in a cultural landscape is endangered

    Invasive neophytes in Germany

    The Japanese knotweed is a plant introduced into Germany

    Not all non-native organisms are unwanted or dangerous. There are few newcomers who can establish themselves and spread independently in a foreign climate. The so-called rule of ten states that only ten percent of all introduced species can survive in the new habitat. The remaining 90 percent disappear after a short time. Another ten percent of the new species can become established, and of this, ten percent lead to negative effects. These plants are called invasive neophytes.

    At around 0.2 percent, the proportion of invasive plants - measured against all neophytes - is negligible.

    definition

    While the neobiotic species only include creatures that have been introduced into foreign areas, the attribute "invasive" designates those animals, plants and fungi that have firmly established themselves in their new habitat. They pose a threat to the native flora and fauna because they have a strong influence on species composition and can displace animals or plants.

    digression

    What financial damage do neophytes and neozoa cause?

    Gray squirrels, raccoons and giant hogweed are alien species in Germany that have now successfully established themselves. Such a spread of non-native species can be at the expense of the new homeland if species that are weak in competition are displaced and habitats are lost as a result. Invasive species can be a major threat to native biodiversity and cause economic damage. According to an estimate by the EU Commission from 2022, these creatures are said to have caused damage of twelve billion euros across Europe.

    Why are invasive neophytes competitive?

    The requirements of these plants correspond particularly well to the conditions in the new habitat. You can fill a previously unfilled vacancy there. Many neophytes have no predators in foreign areas, which means that nothing stands in the way of their spread. In Germany, neophytes increasingly grow on disturbed and nutrient-rich sites such as roadsides and arable land. In contrast, forests or moors are rarely settled by newcomers. This indicates that these plants are adapted to nutrient-rich sites and are tolerant to disturbances.

    Properties that support propagation:

    • Plants produce large amounts of seeds
    • their vegetative ability to spread is very high
    • high adaptability to new environmental conditions

    Neophytes: examples of alien plants

    The beautiful Himalayan balsam is a master at throwing seeds

    The list of neophytes in Germany comprises around 400 plants. This list of neophytes includes established plant species, some subspecies and varieties, and new species that have arisen through crossing and vegetative propagation. In 2022, the EU published the Union List, which lists 66 invasive animal and plant species. Of these creatures, a handful of species are considered serious threats to biodiversity because of their biology.

    scientific origin problem
    hercules tree Heracleum mantegazzianum Caucasus produces up to 10,000 seeds
    Japanese knotweed Fallopia japonica East Asia explosive spread via far-reaching root shoots
    Himalayan Balsam Impatiens glandulifera Himalayas shoots seeds up to seven meters
    Canadian goldenrod Solidago canadensis North America forms impenetrable thickets

    Lupine (Lupinus polyphyllus)

    The species, originally from America, is characterized by a long taproot. A plant develops up to 60 flowers. These develop about 2,000 seeds that can be hurled a distance of six meters. Nodule bacteria sit on these roots, which bind atmospheric nitrogen and make it available to plants. As a result of their spread, soils are becoming more fertile, which is not desirable everywhere. The lupine also spreads on poor soil and displaces species that are dependent on such locations.

    Endangered species:

    • Arnica and cat's paw
    • mat grass and globe flower
    • Orchid and Turk's cap lily

    Ragweed (Ambrosia artemisiifolia)

    The mugwort ragweed is a thorn in the side of allergy sufferers

    In Bavaria, mugwort ragweed is spreading more and more. The species was able to spread unnoticed via bird seed and mainly grows in gardens under bird feeders. As a ruderal plant, the species from North America inhabits disturbed sites and roadsides. It grows on railway embankments, on rubble heaps and on construction sites. Since the pollen can cause severe allergies, the Bavarian Ministry of the Environment has developed an action program to combat the species.

    Black Locust (Robinia pseudacacia)

    The tree comes from North America and is planted in avenues under the name silver rain. The special properties of this species are evident on rubbish dumps: it is resistant to road salt and tolerates emissions. The robinia currently has the greatest potential for displacement. It is able to bind atmospheric nitrogen and enrich it in the soil. Since the wood spreads on poor locations, it ensures that such areas are over-fertilized. Protected and specialized species are being pushed out of these habitats.

    What causes robinias:

    • species-rich semi-arid grasslands are shaded
    • rare orchids are lost
    • insects specialized in orchids cannot find food sources
    • wet slopes are loosened and softened by spurs
    • Nitrogen enriched in the soil is flushed into the water bodies

    Does the individual have to do something?

    As beautiful as some neophytes are, they tend to crowd out native species

    It is primarily a matter for nature conservation to decide on control measures. There are still large gaps in terms of the invasiveness assessment. Many connections within the distribution of such species are unknown. The good will of an individual can quickly lead to negative consequences. Native and endangered species can also be harmed by confusion and carelessness. Each clearing operation means another intervention that can disturb breeding birds or provide an entry point for new species.

    tips

    Make sure that you choose the plants in your garden carefully and, if possible, do not put out propagating plants.

    prevent spread

    If the stocks have already expanded to such an extent that complete clearing seems unrealistic, further spread should be controlled. Make sure that lupins and goldenrods do not propagate from seeds. Cut off the inflorescences in good time before seed formation occurs. The continuous removal of new shoots helps against vegetative spread.

    Use neophytes in the kitchen

    Many neophytes such as potatoes, Jerusalem artichokes or tomatoes have become indispensable in the kitchen. Even among the naturalized plants after 1492 there are herbs that are edible. If the species do not threaten the habitat, comprehensive control makes little sense. Rather, you can harvest the seeds, leaves or shoots of these plants and keep their spread under control through targeted collection campaigns.

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    tips

    Look closely at pictures of both native and non-native species before embarking on a collection tour. Many species look confusingly similar.

    Japanese knotweed

    The plant is considered a medicinal herb in China and Japan and is used for healing teas. Their young shoots taste like rhubarb leaf stalks. They can be processed into tasty dips and sparkling jams. If they are still very young, the shoots can be eaten raw.

    lupine

    Lupine seeds are a relatively unknown ingredient in food. Their nutritional content is comparable to that of related legumes such as peas and soybeans. Before the seeds can be eaten, the bitter substances must be removed. In traditional methods, this is done by storing in salt water for 14 days. The seeds are then boiled in fresh water several times. Lupine seeds can be prepared as a pea vegetable or used in salads.

    frequently asked Questions

    What are alien species, neophytes and neozoa?

    In Germany and the neighboring German-speaking countries, plants are usually referred to as neophytes and animals as neozoa. In English usage, a subdivision into plants, animals and fungi is unusual. Alien species are collectively referred to as "alien species". If the species have a repressing character, they are considered "invasive species".

    How dangerous are neophytes?

    There are some species that pose health risks to humans. However, not everyone reacts in the same way. Sensitive people and allergy sufferers should exercise caution. Giant hogweed produces a substance that destroys the skin's natural sunscreen when touched. Exposure to normal sunlight can cause severe burns and blistering.

    Until November, the ragweed produces billions of tiny pollens that penetrate the respiratory tract and trigger allergies. The narrow-leaved groundsel likes to settle in pastures and fields. If their poisonous plant parts get into the grain harvest, they can impair health when eating bread.

    Can neophytes be useful?

    Neophytes play an all the more important role, the more remote a location appears. Due to their location requirements, some plants may be more suitable than native plants when it comes to colonizing heavily damaged areas. For many animals, neophytes are now considered important food plants:

    • Copperrock Pear provides food for birds
    • late-blooming giant hogweed provides bees with food when hardly any other plants are blooming
    • Himalayan Balsam is one of the most visited flowering plants by bumblebees in August
    • Horse chestnut leaf miner is an important food source for tits during hatching

    Why are neophytes spreading so rapidly?

    Plants live in a constantly changing world, in which the living conditions also fluctuate continuously. As a result, poorly adapted species are pushed out and better adapted creatures find a new niche. Such processes also take place independently of human intervention. However, many species cannot access these habitats without human transport.

    Do neophytes have to be fought?

    A critical assessment is required as to whether a species actually needs to be eradicated again. Such a measure represents another human intervention, which in turn can allow new unwanted species a portal of entry. It is only through man that locations are created where highly specialized and endangered native species cannot find a basis for life. If a non-native species accidentally stumbles onto this location, it can exploit its growth advantage. Alternative measures such as control or use appear to make more sense in modern nature conservation concepts.

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