Endochory
The Endochorie or digestive spread (intestinal Wanderer) is a mechanism the plants to spread their seed use. It is a sub-form of the so-called zoochory , the spread through animals, and is therefore sometimes referred to as endozoochoria .
functionality
After the so-called diaspores have been consumed by humans or animals, the hard-shelled seeds, stone kernels and nuts are usually excreted again. Digestive juices prepare the seed coat for germination. For some plants such as the raspberry or the African baobab , the intestinal passage of the diaspores is even the prerequisite for their germination. The excreted manure often serves as fertilizer for the seedling.
The diaspores are either with or without attractants.
Red as a signal color
When unripe, the fruits are usually green. By changing color to red, dark blue or black, after which they stand out clearly from the green foliage, they signal their maturity.
Propagation distances
The distance that plants reach depends on the speed with which the nuclei pass through the digestive tract. However, the range of action of the animals also plays a major role. The distance between the mother plant and the seedling spread by endochorium can therefore be between a few meters and several kilometers.
Birds as the most important group of animals in the endochory
Birds are among the most important groups of animals involved in endochoria. Ivy , eucones , lilies of the valley and wild roses are spread through them. The mistletoe is completely dependent on endochore spread by birds. Even the spread of some aquatic plants such as spawning herbs , the hedgehog's cob and many types of sedges depends on water birds such as ducks. The spreading distance achieved by birds is often very short and is regularly only 25 to 50 meters. This is due to the fact that birds often only have a small radius of action and their food passes through the digestive tract very quickly.
See also: Ornithochory (bird spread)
Endochore plants without spreaders
A number of North American trees produce fruit that, when ripe, fall to the ground and rot. These plants include the leather husk tree , the antler tree and the milk orange tree . In North America, however, there are no longer any naturally occurring animal species that eat this fruit. What is striking about these plants is that all of the trees mentioned above develop very large fruits. This has led to the theory that the American megafauna, which became extinct 14,000 years ago, was involved in the endochoric spread of these tree species. Mammoths like the prairie mammoth , mastodons and giant sloths would have been able to consume these plants. In the case of the milk orange tree in particular, this can be explained by the fact that it only occurs in a few and very far apart locations.
Individual evidence
- ^ Connie Barlow, The Ghosts of Evolution, Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms. Basic Books, New York 2000. ISBN 978-0-465-00552-9 .