Study On The Resistance Of Cover Plants On Green Roof In Beijing

With the development of a city, the requirements for green spaces are increasing. The green roof is one of the most effective approaches to solve the problems. It is essential to develop a selection system of green roof plants to improve the area of urban roof garden. The selection system and the appraisal of some green roof plants were discussed in this article.The investigation results revealed that more than 100 species of 80 genuses, 43 families had been used in green roofs of Beijing. The arbors took 24%, the bushes took 36%, the lianas took 7%, and the herbs took 33%. The proportion of arbor and bushes was 1:1.5. The proportion of tree types was small, and the proportion of bushes was relatively big. The paper also carried on the quality synthetic evaluation to the plant growth situation.The morphological and physiological indexes of drought resistance, heat endurance and cold tolerance were measured and analyzed with Sedum linear Thunb, S. sarmentosum Bunge and other species. Along with arid coercion time's increase, the leaf blade relative conductivity of Sedums had a varying degree to elevate, the scope of S. reflexum Tripmadam was biggest, and the rate of increase about Dianthrus spiculifolius Schur was not obvious. The basic potential state of SOD about Sedums assumed that the trend of escalation increased firstly, then reduced. The results showed that, the drought-resistant arranging from strong to weak were: S. spurium'splendens'> S. spurium'Coccineum' > S.kamtschaticum Fisch > Sedum Lineare Thunb> Sedum reflexum Tripmadam > Sedum sarmentosum Bunge> S.spectabile Boreau > Sedum sexangulare L.> Dianthus spiculifolius Schur> Limonium bicolor(Bge.)o.Ktze> Viola philippica Car.According to the treatment temperature, the heat resistance behaved strong property arranging from strong to weak were: S. reflexum Tripmadam> Sedum Lineare Thunb > Viola philippica Car > Dianthus spiculifolius Schur > Sedum sarmentosum Bunge > S. spurium'splendens'> S.kamtschaticum Fisch > S. spurium'Coccineum' > Limonium bicolor(Bge.)o.Ktze> Sedum sexangulare L. > S.spectabile Boreau. And the half lethal temperature of Sedum reflexum Tripmadam was 65.97℃, and S.spectabile Boreau was 48.94℃.With the cold tolerance, the ability of cold resistance of Sedum spurium 'splendens'and S. reflexum Tripmadam were better than Sedum Lineare Thunb and Sedum sexangulare L.. The ability of cold resistance of Dianthus spiculifolius Schur was better than Limonium bicolor(Bge.)o.Ktze and Viola philippica Car.Moreover, we have surveyed many plants on field, and find that some species such as Dianthus spiculifolius Schur and partial Sedums were suitable for green roof in Beijing. The theory and the practice bases were provided for plant selection and application in Beijing in this paper.