DiscussionThe germination of Astragalus adscendens was favored by a low thermal shock (60°C-5 min), but the effects of heat treatment on the rest of the species did not significantly stimulate their germination. The behavior of Astragalus adscendens seeds at low temperatures (60°C) implies some heat-induced physiological dormancy (Clarke et al. 2000, Baskin and Baskin 2001). In the present study, seeds of most species failed to germinate at the high temperatures tested (120°C-5 min). Perhaps their coating is not able to protect from the effects of such high temperatures. The lethal effects of high temperature shock on seeds of several species have been previously documented (Keeley and Bond 1997, Thomas et al. 2007, Dayamba et al. 2008, Paula and Pausas 2008, Chou et al. 2012). The mean germination time of the species was not affected by heat treatment, except the mean germination time of Phlomis olivieri, which is sensitive to fire. The annual herbaceous species (Poa bulbosa), dominant in the study area and shown to be favored by fire (Naghipour Borj, personal observation), failed to germinate in ...