A TRANSIENT EXPANSION OF SOWN PLANTS AND DIASPORE LIMITATION.

Dispersal limitation was studied in a species-rich meadow (53-65 species of vascular plants per 1.1 m²) to which a mixture of weeds was accidentally sown. Even if none of the sown species belonged to the local species pool, five species successfully established. Of them one persisted for 7 years, however declined from 41 individuals in 1995 to 1 individual recorded in 2001. These results can be interpreted as an evidence for short-term diaspore limitation. In contrast, long-term data indicate no diaspore limitation. Establishment of weeds in subplots with a lower number of species and individuals was higher than in other subplots, indicating that plant establishment in the studied open-canopy grassland is affected by the spatial pattern of present plants. [ABSTRACT FROM AUTHOR]