Autumn crocus is a common species in Central Europe and is able to reach high population densities in extensively used grasslands. Due to its toxicity, autumn crocus can be a problem for grassland management. Therefore, on extensively used grassland conflicts between control measurements and natural conservation can occur. This thesis describes the abundance and the population structure of Colchicum autumnale in the municipalties Alland and Glashütten in the Vienna Woods. It was analysed, if there is a trade off between vegatiative and generative reproduction and if the management has an influence on the plant. In total 279.91 ha grassland were mapped and the abundance of autumn crocus estimated. In addition the population structure on 13 lots with a high density of Colchicum autumnale was analysed and 23 farmers were interviewed. Autumn crocus was found on 70 % of the total grasslandarea and was found in moderate to high density on 39 % of the grassland area. In the investigated populations an average of 69 plants/m could be found and the number of seedlings was high on all plots. An early management date (May), the management as mown pasture, more than 2 cuts per year and the use of fertilisers have a negative effect on autumn crocus. Within vegetative clusters, vegetative reproduction, the number of capsules per plant was less than the number of capsules of single plants. According to the farmers, livestock avoids C. autumnale, if the fooder supply is sufficient. Therefore, high amounts of autumn crocus is mainly a problem for farmers selling their hay.