Seed rain on alpine ski runs in Switzerland

摘要

Spatial and temporal variation in seed rain was studied in two un-restored ski runs at the Kakobshorn Mtn.(NE Swiss Alps), at ca. 2500 m a.s. 1. The study carried out from 1996 to 1998 included density per m~2, alpha diversity(species richness), an species composition of the seed rain vs. that of the resident vegetation. This is the first detailed study of seed rain on machine-graded ski runs at high elevation. Density of seed rain peaked mostly in late summer; on the other hand, alpha diversity var- Ied most frequently with one peak after spring snowmelt and another towards the end of the Growth period.