Ornithochory
The ornithochory ( old Greek ὄρνῑθ- [ornith-], stem of ὄρνις [ornis]: "bird" - and χωρίς [choris]: "separated, separate" = bird spreading ) is a spreading mechanism in which birds play the role of spreading the diaspores take over.
Adjustments
Similar to animal pollination , the spread of animals has often led to a coevolution between plant and spreader, whereby the specializations on each other are usually less strong, since several mechanisms of spread are often realized in parallel ( polychory ). Nevertheless, some common features can be identified. Since birds have a pronounced sense of sight, the ( generative ) diaspores (these can be seeds, fruits, collective fruits or fruit clusters, see below) are often red, yellow or shiny black, thus forming a strong color contrast to the surroundings. The odor of the diaspores, however, is usually less pronounced. In addition, they usually remain on the stem axis when the seeds are ripe , are soft-skinned and small to medium-sized.
Ecological importance
Birds are very important for seed dispersal . In Central Europe alone, 186 wood plant species were identified whose diaspores are ornithochoric. Many birds contribute to this by hiding diaspores (especially blue jays and pine jays ) as stocks, but not using all of the depots for food ( hiding spread ). This is the case with oak , beech , hazel species and Swiss stone pine , among others . The birds mentioned can justify often entire tree populations in this way, in the forestry are called Hähersaaten. The greater part is certainly spread through endochoria (digestive expansion).
The (endo-) ornithochoric spread plays a major role, especially when repopulating gaps in settlement caused by disturbances (fires, floods, volcanic eruptions, etc.). The dispersal units quickly reach unpopulated places with the bird droppings. This means that these plant species, in addition to the anemochorous species, often belong to the pioneer plants and thus form the so-called initial stage of succession .
Also epiphytes (such as the. Mistletoe ) are usually ornithochor, their seeds are brought by the birds with their droppings directly to the sites to which they have adapted: high branching points by trees.
In the case of mosses in particular , the spread through the use of plant parts as nesting material plays a greater role.
Examples
Examples of ornithochore species that are endochorically spread are:
- fleshy seeds as diaspores
- The common peony
- Representative of the magnolias
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Stone fruits as diaspores
- The bird cherry
- Representative of the olive trees
- Representative of the genus elderberry
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Berries as diaspores
- Representative of the dragon trees
- Representative of the genus privet
- Representative of the currants
- Representative of the grapevine
- Representative of the mistletoe
- Representative of the blueberries
- Tepin (the archetype of peppers -Art Capsicum annuum )
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Collective fruits as diaspores
- Representative of the roses (common nuts )
- Representative of the genus Rubus ( collective drupes )
- The rowanberry ( apple fruit )
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Fruit associations as diaspores
- Representative of the genus of mulberries
swell
- Peter Sitte , Elmar Weiler , Joachim W. Kadereit , Andreas Bresinsky , Christian Körner : Textbook of botany for universities . Founded by Eduard Strasburger . 35th edition. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1010-X .
- Peter H. Raven, Ray F. Evert, Susan E. Eichhorn: Biology of plants . 3. Edition. de Gruyter , Berlin / New York 2000, ISBN 3-11-015462-5 (English: Biology of plants . Translated by Rosemarie Langenfeld-Heyser).