Adventurous plant
Those plants are referred to as adventitious plants, which were able to establish themselves in a place not corresponding to their area of origin due to anthropogenic influence. Adventive species are all wild species that have only been established with the help of humans (without the cultivated plants), in contrast to the native species (with the technical term indigenous ).
Another language has become established within ornamental plant breeding and aquaristics. In these areas, those plants are named as adventitious plants that have been produced by vegetative propagation as subsidence or offshoots (pieces of sprout or sprouted bulbs that develop roots through contact with the ground). This use of the term is independent of the botanical use.
Depending on the question and perspective, adventitious plants are divided into different subcategories:
1. Classification according to time
- Archaeophytes were introduced before 1492
- Neophytes were introduced or immigrated after 1492.
The year 1492 is a conventionally chosen reference point. With the "discovery" of America and the age of discovery and colonialism , alien species from other parts of the world came to new areas on a large scale. Most of the archaeophytes immigrated with the introduction of agriculture (in the Neolithic ). The status of a species as an archaeophyte is usually derived (from the location and ecology of the species) and can hardly be directly proven.
2. Classification according to degree of establishment
- Agriophytes : Species that have invaded natural or near-natural vegetation and could survive here without human intervention.
- Epökophytes : Species that are only naturalized in vegetation units shaped by humans, such as meadows, weed flora or ruderal vegetation, but here are firmly established.
- Ephemerophytes : Species that are only introduced inconsistently, that die briefly from culture or that would disappear again without a constant replenishment of seeds.
3. Classification according to route of immigration
- Spontaneous immigrants (sometimes referred to as "acolutophytes") immigrated on their own without direct human assistance, for example when new locations were created through culture or soil changes.
- Companions (sometimes also "xenophytes") were brought in by human transport. Examples would be seed companions that were unintentionally sown due to their similarity to cultivated plant seeds, or “wool adventures” that were dragged into the wool fleece during the transport of sheep's wool.
- Feral species in the narrower sense are those that were originally cultivated, but later escaped from the culture and were able to spread on their own. Such descendants of original cultural clans are subject to natural evolution as they become wild and can more or less quickly differ both from the culture form itself and from the original wild clan that preceded the culture. Sometimes these are referred to as "ergasiophygophytes".
Adventitious plants are often found at freight stations, along railway lines and port areas as well as airports, but also on roads. Seeds of many species were accidentally imported there with the import of goods (so-called agochory ). Occasionally, seed contamination also introduces new plants that could reproduce for a short time (so-called Speirochoria ). Agochory and speirochory are sub-forms of hemerochory . The seeds can also hang in wheel arches so that they can be transported and distributed along highways. The proportion of adventitious species in open ruderal corridors at such locations can exceed 30% of the flora of these locations. In natural and near-natural vegetation, adventitious plants are much rarer. Their share is between zero and about 5%.
Individual evidence
- ↑ FG Schroeder: On the classification of the anthropochores. In: Vegetatio. 16, pp. 225-238 (1969). (on-line)
- ^ Ingolf Kühn , Stefan Klotz: Floristic status and alien species. In: Series of publications for vegetation science. 38 (2002), pp. 47-56.