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Gewählte Master / Diploma Thesis:

Alexandra Plicka (2015): Erfassung der Populationen von Orchis militaris und Orchis ustulata im Planungsgebiet LIFE+ Traisen im Natura 2000 Gebiet "Tullnerfelder Donauauen".
Master / Diploma Thesis - Institut für Botanik (Botany), BOKU-Universität für Bodenkultur, pp 83. UB BOKU obvsg FullText

Data Source: ZID Abstracts
The Natura 2000 site Tullnerfelder Donauauen is characterized by being a habitat of many rare indigenous plant species. Within the scope of the Life+ project the Traisen river is going to be restored in the concourse area of Traisen and Danube aiming the reconstruction of natural riverside forest conditions. In this master thesis the populations of the rare orchid species Orchis militaris and Orchis ustulata were monitored in the region near the hydroelectric power plant Altenwörth. The investigation of recent orchid population numbers was carried out during spring 2014. Most of the orchid habitats were detected near th the hydroelectric power plant and in the meadows accompanying the access road. Meadows in the investigation area were characterized by differing habitat structures from wetlands to hot and dry sites underlying varying cultivation methods and included natural and formerly agricultural sites as well. Overall numbers at the monitoring site of Orchis militaris individuals were significantly higher then Orchis ustulata numbers. In the western regions of the study area only populations of small density and single individuals were observed. The main reason for this circumstance may be the lack of meadow cultivation management which leads to uncontrolled growth of shrubs and trees in the formerly open spaces. In these areas only Orchis militaris was found because this species is more tolerant to environmental influences then Orchis ustulata. One important factor supporting the growth and long term establishment of orchids, especially Orchis ustulata is the ecological quality of meadow cultivation management procedures. Unlike Orchis militaris Orchis ustulata seems to be more sensitive to ecological changes caused by the regionally well established neophyte plant Solidago. In order to protect Orchis ustulata populations of Solidago should be drastically reduced by cultivation management. Long term monitoring of orchid populations and accompanying flora completed by vegetation management plan is critical for preservation of the orchid population structure and improvement of growth condition.

Beurteilende(r): Bernhardt Karl Georg
1.Mitwirkender: Rasran Leonid

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