Germination capacity and temperature dependence in Mediterranean species of the Balearic Islands

To test the germination capacity and its temperature dependence in Mediterranean plants, sixteen species representative of a diversity of habitats of the Balearic Islands were selected. The percentage of germination, the half-response time and the dormancy period of these species were studied at three alternating temperatures: 5-15 C, 10-20 C and 15-25 C. Large differences were found among species in all three parameters studied. The influences of the temperature incubation in germination behaviour depended strongly on species, although the optimum temperature range to reach maximum germination was found to be 10-20 C for most species. Although part of the endemic flora of the Balearic Islands currently has a limited and regressive distribution, no clear pattern was observed when comparing endemic and non-endemic species. In fact, some of the endemics presented unfavourable characters, particularly a relatively high temperature independence of their germination pattern.