Speirochorie
As Speirochorie is called accidental spread of the plant as seed companion. This spread of plants by humans is, together with the agochory and the ethelochory, a sub-form of the hemerochory .
The poppy , for example, is one of the plants that are spread by speirochor . It is a plant originally native to the Mediterranean area, the seeds of which were mixed with the seeds of the plants that were important for humans, brought to Central Europe. The same applies to the archaeophytes, chamomile , cornflower , corn wheel and buttercup .
It is characteristic of speirochore plants that they were sown on a soil prepared by humans and there they compete directly with the specifically cultivated species. Author Crosby estimated that in 1912 alone, imports of clover and grass seeds brought between two and six billion weed seeds to Britain. Many of the plants introduced by the agorochory turn out to be problematic for the ecosystem. For example, a species of weed with grain seeds imported from the USA was established in India, which has proven to be very disadvantageous for agriculture there.
Some authors such as Lüttig, Kasten and Kowarik do not consider the spread of plants via sperochory to be very frequent, since seeds are cleaned before sowing, so that the seeds only rarely contain seeds from undesired plants. Increased use of herbicides , fertilization and deeper tillage in today's agriculture lead to further decline. However, the experience in Australia indicates that this does not seem to apply to all plant seeds. Cuscuta campestris , classified as a problematic bioinvasive agent in Australia, was accidentally introduced to Australia together with basil seeds in 1981, 1988 and 1990 . The tiger nut , which has been increasingly appearing as a field weed in the Netherlands since 1970 , was probably carried away by gladiolus bulbs to speirochor . Holdings are now also known in France , Switzerland and Germany . In the Netherlands, control measures against the tiger nuts were introduced as early as 1984.
literature
- Bernhard Kegel : The ant as a tramp. From biological invaders. Heyne, Munich 2002, ISBN 3-453-18439-4
- Tim Low: Feral Future. The untold story of Australia's exotic invaders. Penguin Books Australia, Ringwood 2001, ISBN 0-140-29825-8
- Angelika Lüttig, Juliane Kasten: Rose hip & Co. Flowers, fruits and spread of European plants. Fauna, Nottuln 2003, ISBN 3-935-98090-6
- Ingo Kowarik ; Biological invasions. Neophytes and Neozoa in Central Europe. Ulmer, Stuttgart 2003, ISBN 3-800-13924-3
Individual evidence
- ↑ Ingo Kowarik: Biological Invasions: Neophytes and Neozoa in Central Europe . Eugen Ulmer, Stuttgart (Hohenheim) 2003, p. 137, ISBN 3-8001-3924-3 .