Hohenheim groundwater experiment
The Hohenheim groundwater experiment was set up at the University of Hohenheim in 1952 by Heinz Ellenberg at the suggestion of Heinrich Walter and continued in the following years by Helmut Lieth and Reinhard Bornkamm .
With this experiment, the ecological potency , the auto- ecological optimum and the synecological optimum of plant species can be shown in relation to their competition.
Test execution
The Hohenheim groundwater attempt four were grass species ( meadow foxtail , oat grass , orchard grass and Upright brome ) separately on a bed with a continuously decreasing groundwater deep seeded. All four species reached their maximum height in an area at medium groundwater depth. All four species have their auto-ecological optimum there . The groundwater level had no significant influence on the dry matter yield with pure sowing; it was roughly the same for all four grasses.
In one variant, the grass types were sown in a bed in mixed seeds, i.e. exposed to competition. The result showed that the oat is the most competitive species. It pushes the meadow foxtail into the moist part of the bed, where it then becomes dominant. The upright bristle is pushed into the dry area by the oat, but it also occurs in the moist area. The ball of grass behaves indifferently to the influence of the soil water balance. For the three other types of grass, it was thus possible to show the soil water balance at which they reach their synecological optimum .
A grass species with higher ecological potency can maintain its auto- ecological optimum and displaces the other grasses to species-specific areas with either a lower or greater groundwater depth to their synecological optimum.
In the literature, the Hohenheim groundwater test is mostly only presented today with the three grass types, meadow foxtail (moist locations), oat grass (medium locations) and upright trespe (dry locations).
See also
literature
- Heinrich Walter: Introduction to Phytology . III. Basics of plant distribution. Part I: Location theory. 566 S. Ulmer, Stuttgart. 2nd edition 1960.