Ecology of seed dormancy and germination in sedges (Carex)

摘要: Abstract The genus Carex , with its wide distribution and large number of species yet a rather uniform life history, is very convenient group for comparative studies germination ecology at the generic level. combination strict or conditional primary dormancy, light requirement germination, low constant temperatures, positive response to diurnal temperature fluctuations an induction secondary dormancy in late spring by increasing environmental temperatures are attributes that were found be characteristics shared almost all investigated, though there was variation between degree which these characters expressed. In species, broken stratification few gained ability germinate 0.9 mg), probably due thicker seed coat hence higher resistance germination. Differences sedges various habitats could not established. However, tendency limits forest sedges. Many wetlands open sites showed greater capability respond fluctuating than dry sites. These traits only enable accumulation seeds soil, but also constitute seasonal regeneration strategies rely on high longevity formation persistent banks. Temperate Carices mainly adapted exploit temporally spatially infrequent occurrence canopy gaps become available early summer, whereas colonization beginning vegetation period largely prevented important Cyperaceae generally. A diversity responses, however, can related families, Juncaceae Poaceae. Our present knowledge sufficient determine unequivocally whether phylogenetic component contributes significantly behaviour certain tendencies clearly indicated.