Stenocracy

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The Stenökie (from the ancient Greek words στενός stenos , German , tight ' and οἶκος oikos = house, residence composed) and Steno potency refers to the property of biological species , only a narrow range of variation of one or more environmental factors to endure so a low tolerance have.

Individuals of stenoic or stenopotent species are only viable in a very limited spectrum of biotopes , as their potential expansion ( fundamental ecological niche or fundamental niche ) is severely restricted due to their narrow response range and this often largely corresponds to the real expansion ( realized ecological Niche or real niche ) of the species. Accordingly, stenocs or stenopotent types are often pointer types .

Depending on the respective environmental factor, one speaks of:

Each species has a maximum within its growth curve, i.e. the representation of its vitality as a function of a certain environmental factor. It is typical for stern species that their vitality drops again very quickly around this maximum and that their individuals can no longer survive even with a comparatively small deviation of the relevant environmental factor from the ideal range for the respective species. In the case of very wide tolerance ranges, on the other hand, the term Euryökie or euryök species is used to distinguish it from Stenökie .

The contrast between the two terms for the environmental factor soil moisture is illustrated by the figure below, in which the holm oak and black alder represent stenohygre species, while the common beech is a euryhygic species.

Graphic of the shift in the power range

Depending on the position of the maximum within the growth curve, a distinction is made between stenoke species again in three classes, each characterized by a specific prefix. If the highest vitality of the species can be observed in the area in which the environmental factor in question is weakest, the prefix oligo (old Greek little) is used; if the environmental factor is medium, the prefix meso (old Greek between) is used and if the environmental factor is more pronounced Expression of the environmental factor the prefix poly (old Greek a lot). Transferred to the above example, the holm oak is an oligo stenohygre and the black alder is a poly stenohygre species.

See also