Epichory

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Under bur or Epizoochorie or Anhafter refers to the on animals adjusted spread of seeds or fruits of a plant by the adhesion to the body surface of an animal. The epichory is a special form of zoochory . In this case, the seeds or fruits of the plants must have appropriate characteristics in terms of structure and function in order to enable this type of spread.

Methods

Fruit of the burdock bedstraw in the SEM , magnification 40 times
Fruit of the burdock bedstraw in the SEM, magnification 100x
Fruit of Uncarina ankaranensis
  • The first method is the attachment of the fruit or fruit bunches to the fur, hair of an animal, also an insect (eriochory).
  • Other possibilities are attachment to the hooves or the skin of animals. The clinging to hooves is z. B. by the trample , used in dry, steppe - or desert areas. Here seeds and their shells withstand the high pressure that occurs when the animals appear. In addition, the Velcro devices are so hard and pointed that they can get stuck on the animals' feet or in their hooves.
  • An unspecialized method is shown by some marsh and aquatic plants whose diaspores float on the water surface (nautohydrochory) and are transported by water birds . The diaspores are so light that they can float on the surface of the water and stick to the animals' feet.
  • Some plant seeds stick to damp surfaces. Plants with this method of spreading ( hydroepizoochory ) are called water or adhesive . In the duckweed family , the entire plant is transported with it due to its small size of 0.5 to 1.5 mm.

The seed or fruit pods are specially morphologically adapted to ensure adherence:

  • More sticky , sticky fruits ((K) Collepizoochorie) are seeds and fruits of plants that secrete sticky secretions around the peel when wet and stick to the animals, such as Ufer-Wolfstrapp , some garden pumpkins .
  • The Klett Hafter , Klett fruits (Euepizoochorie) are is in which the seeds / fruit capsule hooked on animals and distributed so that special seeds / fruit, such as barnacles , cleavers , Geum , Datura , henbane .
    • A sub-form are pointed borehole or wedge fruits (burdock), they usually bore into the ground (trypanocarpy), but can also bore into the fur or directly into the skin of animals passing by, such as the heron beak or the Heteropogon contortus .

Advantages and disadvantages of epizoochory

Epizoochory is an effective way of spreading seeds , in which the plant, unlike endozoochory, does not have to offer a "reward" in the form of carbohydrates , proteins , fats etc. and can therefore spread very " economically ". Another enormous advantage of this type of distribution are the comparatively long distances that the seeds can passively cover and the associated development of new habitats . An extreme example of this is Macquarie Island , which is 950 km south of New Zealand . On this island, all 35 species have been introduced through epizoochory, probably in the plumage of birds. Another reason for the great distances is the fact that the plants spread by epizoochory are also transported by the large predators among the mammals , which roam much larger areas than the herbivores .

Disadvantages in some cases are the dependence on the weather, namely when the seeds do not have any explicit adhesive devices and are dependent on the adhesive forces that bind them to the animals via damp earth or mud. Furthermore, the plants are exclusively dependent on the roaming animals. This can result in comparatively poor conditions for the respective plant if it is in an unfavorable location that is rarely frequented by animals.

literature

  • Distribution type according to Düll and Kutzelnigg 1986, and Paul Müller-Schneider 1983, In: Publications of the Geobotanical Institute of Eidg. Tech. Hochschule, Stiftung Rübel, in Zurich, volume (year): 125 (1995), online (PDF; 13.2 MB).

Individual evidence

  1. ↑ Ignazio Li Vigni, Maria Rita Melati: Examples of seed dispersal by entomochory. In: Acta Botanica Gallica. 146 (2), 1999, pp. 145-156, doi : 10.1080 / 12538078.1999.10515813 , (PDF; 1.4 MB).
  2. ↑ Wolfgang Frey, Rainer Lösch: Geobotany. 3rd edition, Springer, 2010, 2014, ISBN 978-3-662-45280-6 , p. 339.
  3. ↑ E. Ulbrich : Biology of fruits and seeds ‹Karpobiology›. Springer, 1928, ISBN 978-3-642-51789-1 (reprint), pp. 117-133 f.