GERMINATION ECOLOGY OF THE ENDANGERED GRASSLAND BIENNIAL GENTIANELLA-CAMPESTRIS

The germination ecology of the endangered biennial grassland forb Gent ianella campestris was studied. The seeds had a primary dormancy which was overcome by cold-stratification. Seeds buried in the soil became germinable in early spring (February), and autumn-sown seeds germinate d during a four-week period in late spring (May). Exhumed seeds germin ated in both light and darkness and in situ germination occurred even at 15 cm depth in the soil. No persistent soil seed bank could be dete cted in populations of G. campestris, and very few experimentally buri ed seeds were viable after 21 months in the soil. Together, these resu lts indicate that the species has a transient seed bank, in which case yearly seed production is important for maintaining populations and p reventing local extinction.