The comparison of selected life-history characteristics of Mesembryanthema species occurring on and off Mima-like mounds (heuweltjies) in semi arid southern Africa

摘要: Selected life-history characteristics of Mesembryanthema species occurring on and off mima-like mounds (heuweltjies) were compared at Tierberg in the southern Succulent Karoo, South Africa. Seed production, number seeds retained seed capsules germination behaviour measured fourteen which representatives two sub-families: Ruschioideae Mesembryanthemoideae. Species onheuweltjies had low overall high retention with those offheuweltjies. A strong negative correlation was found between degree maximum germination. It proposed that rapid dormancy flats would be a viable strategy where competition for safe recruitment sites is strong. are long-lived woody shrubs, thus resulting levels seedling mortality probably do not have major impact population dynamics.Heuweltjies intense disturbance. Plant occur can also offheuweltjies disturbed vegetation. Opportunistic allow these to colonise areas.Heuweltjie act as pioneers successional process results ultimately re-colonisation species. Phylogenetic factors may determine distributions. Members Mesembryanthemoideae did undisturbed areas. Most but few occurred shared similar The primitive exhibited by enable them exploit conditions.