The nature reserve `Lange Rhoen` (2,666 hectares) is situated in the border area of the German federal states of Bavaria, Hesse and Thuringia. For some decades already the large-leaved lupine (Lupinus polyphyllus) has grown over a large number of species of crane's bill-yellow oat meadows and mat-grass pastures, and thus implies habitat changes for the leading species of the Rhoen region (meadow breeders: black grouse (Tetrao tetrix) and corncrake (Crex crex). The preservation of representative sections of this man-made landscape is thus jeopardized. The reasons for the settlement success and thus the extensive spread of Lupinus polyphyllus in the uplands of the Rhoen region was examined in this paper. The consequences for the variety of species in protected types of biotope in the Rhoen biosphere reserve have been described, and the possibilities for a future management of the Lupinus stock were determined and described by means of cultivation trials. The results can be summarised as follows: 1. The neophyte Lupinus polyphyllus originally resident in the north-western regions of America was used as sub-seed for location improvement in spruce afforestation in `Lange Rhoen`. This intentionally caused anthropic long-distance dispersal of Lupinus polyphyllus was the pre-requisite for its further spread. 2. The areal dispersal of the neophyte could occur only on account of the utilization changes in the last few decades. On account of the changes in the framework conditions in agriculture (fallow land, late hay harvest, minimum cultivation), the nature of the neophyte Lupinus polyphyllus to niching was supported in the ecological upland meadow system of the `Hochrhoen` region. Contractual protection of nature ensures land cultivation by premiums only, which supports the dispersal mechanisms and strategies of Lupinus polyphyllus in addition. 3. The amplitude of plant populations, in which Lupinus polyphyllus settles, reaches from a large number of species of mat grass and yellow oat grass to wet meadows and marshy wasteland meadows, whereby the priority of their dispersal lays in the fresh locations of the yellow oat grass. 4. The dispersal of Lupinus polyphyllus takes place primarily through generative means. One hundred-and-fifty to two thousand seeds of each adult plant are catapulted across a radius of 6 metres every year. The diaspores contain a high amount of nitrogen and alkaloid and reach a high capability of germination at all temperature stages. However, for germination the seeds depend on open locations (safe sites) with little competition which are produced by the thinning of the turf, by mechanical damage of the turf during cultivation or by animals. The vegetative dispersal by polycormons may amount up to 0.2 metres per year. 5. As soon as Lupinus polyphyllus penetrates the ecological upland meadow systems of mat grass and yellow oat grass, it starts growing over them as from the second year (zone change in upland meadows). This causes a shading of the original vegetation (among others leading species of the nature reserve), displacing heliophilic species and dissolving the dense grass and weed layers in the course of the time. Diaspores find ideal germination conditions. 6. In addition, Lupinus polyphyllus will enrich its stock with nitrogen by means of N2 bonding bradyrhizobias, and the root system reaching deep down into the basaltic subsoil absorbs nutrients from the subsoil, transports them into the topsoil and near-surface phytomass, and thus enrich Ah-horizons poor in plant nutrients (nutrient pump). On account of the nutrient enrichment, the stock of species shifts in favour of nutriophilic grasses and weeds. In Lupinus populations, the nutrient concentrations of nitrogen, calcium and magnesium are distinctly higher than in neighbouring yellow oat meadows. From the end of June to the middle of August, the highest nutrient concentrations are bound in the topsoil biomass whereby the nitrogen concentration in the root of Lupinus polyphyllus starts increasing as from the middle of June. The biomass production in Lupinus dominated populations is higher by one third than in neighbouring locations without Lupinus polyphyllus. 7. Lupinus polyphyllus can be controlled by the use of machines as well as by sheep. The point in time (prior to ripening of the seeds) and the repetition of the measures are decisive for the success. Each control measure has to be carried out at least twice a year over a period of three to five years.