Seed dormancy and germination ecology of Lamyropsis microcephala: a mountain endemic species of Sardinia (Italy)

Lamyropsis microcephala only occurs in a very restricted area in the Gennargentu massif (CE-Sardinia, Italy) at 1450-1700 m a.s.l. This rare species has been inserted in the International Union for Conservation of Nature (IUCN) Red Lists under Critically Endangered. In this study, the effect of a pre-chilling period (90 days at 5°C) on germination was investigated as well as the ability of this species to form a soil seed bank. L. microcephala seeds exhibited type 2 non-deep physiological dormancy. Pre-chilling increased the final germination percentages, the germination speed and the temperature range at which high levels of germination were observed. The high optimal germination temperatures (ca. 70% germination at 30°C) demonstrate that this species is well adapted to a temperate climate and the lack of a persistent soil seed bank represents a rarity trait that likely exacerbates the threats to the survival of this species.