Preliminary Studies On Plants Adaptability And Propagation For Green Roofs In Beijing

A sample survey of green roofs in Beijing shows that at this stage, the main patterns of green roofs in Beijing are intensive green roofs, which were concentrated on guesthouse, office buildings and residential areas. Extensive green roofs are the main patterns for large-scale extended, and nowadays its on initial phase. Lack of plant materials are bottlenecks for the development of green roofs in Beijing. So it's important to select the suitable plants for the eco-green roofs'develepment in Beijing areas.Form Beijing or surrounding area, selected plants meeting the special conditions of extensive green roofs. Non-succulent plants include: Thymus serpyllum var.mongolicus,Rehmannia glutinosa, Caryopteris X clandonensis, Iris spp, Allium giganteum, Saponaria. ocymoides, Ameriaca maritime, Capparis spinosa and so on; and introducing crassulacean plants which were successful used on green roofs in Germany, they are: Sedum acre, S. spurium 'Coccineum', S. spurium 'splendens', S. sexangulare, S. album'Coral Carpe', S. reflexum, S. kamtschaticum ellacombianum and so on. By the experiment, selected the best plants suitable for drought, hardy, hot and humidity conditions.This experiment results shows that, arranging form strong to weak, no-succulent plants' drought-resistant were: Iris spp.>Allium giganteum> Thymus serpyllum var.mongolicus >Caryopteris X clandonensis> Saponaria.ocymoides> Rehmannia glutinosa. Succulent plants' drought-resistant were: Sedum sexangulare>Sedum acre>Sedum telephium>Sedum kamtschaticum ellacombianum> Sedum spurium'splendens'>Sedum spurium 'Coccineum'. About hot and humidity resistance, no-succulent plants which behaved strong property arranging form strong to weak were: Iris spp, Thymus serpyllum var.mongolicusand,Caryopteris X clandonensis; while the succulent plants' were: sedum spurium 'Coccineum' and Sedum kamtschaticum ellacombianum. The extermination of overwintering rate of all plants including no-succulent and succulent shows that all plants behaved strong property in winter, and the rate of overwinering were all 100%.The tissue culture of Thymus serpyllum var.mongolicus was studied and the most optimal method of sterilization was in the solution of 0.1%HgCl₂ and tween-80 for 8min.The suitable medium for propagation was MS + 6-BA 1.5 mg·L^-1 + IBA 0.1 mg·L^-1 which the best propagation numbers was 57.The optimum rooting medium was 1/2MS + IBA 0.5 mg·L^-1+20 g·L^-1suger. The ration rooting reached 100%. The sand was used as the transplant media, the survival rate reached 50%.