Studies On The Selection Of Plants And Substrates Of Roof Greening Of Lawn-style In Guangzhou

The roof which acts as the fifth of building elevation,has been paid more and moreattention in recent years.In present society,each estate values a highly prized.Thegreen-roof has been the first choice for solving the contradiction between architecturalarea and greenery area.The lawn-style green roof has been widespread used inGuangzhou area because of its low cost and easy maintenance.The plant which hasbeen only popular used in lawn-style green roofs nowadays in Guangzhou is Sedumlineare Thunb.Long-term single species used are not good for the stability of greenroofs.In order to rich the diversity and stability of lawn-style green roof,the researchsaims to study the plants and substrates for green roofs,through field introduction andpresent cultivated species.The results were as follows:1、Through observing of the20species during the summer and winter,we preliminaryscreened that13species performed excellently,there are Sedum lineare、Sedummexicanum、Sedum sarmentosum、Sedum polytrichoides、Sedum emarginatum、Sedumalfredi、Kalanchoe blossfeldiana、Sedum aizoon、Tradescantia spathacea、Setcreaseapurpurea、Murdannia loriformis、Callisia repens、Alternanthera dentata.2、During the further phenological observation of the thirteen species,All of them canbe normal growth in Guangzhou area.Considering of the require of lawn-style greenroofs,the research sets a five-point system during the performance of oversummeringand overwintering,surival rate,ornamental,coverage rate,green period and the easewith which getting the material.With comprehensive mark,we found Sedum lineare、Sedum polytrichoides、Sedum emarginatum、Sedum alfredi、Tradescantia spathacea、Setcreasea purpurea、Murdannia loriformis、Callisia repens can be candidate plantsfor green roofs.3、Depending on the climate of Guangzhou,the moisture and temperature have astrongest infiuence on the growth of plants,it is a test of heat and drought resistant forthem.The research made heat and drought resistance experments on the eightspecies.Through drough-resistant test,we determined the soil water content,morphology of plants,the relative electric conductivity in leaves,the potential state of MDA、SOD of plants,through subject function to comprehensive evaluation,thedrought-resistant arranging from strong to weak were:Callisia repens﹥Sedum lineare﹥Sedum alfredi﹥Tradescantia spathacea﹥Sedum alfredi﹥Setcreasea purpurea﹥Sedum emarginatum﹥Murdannia loriformis.According to heat resistant treatment,thehalf lethal temperature of Murdannia loriformis is61.44,Tradescantia spathacea is59.07,Sedum lineare is57.07,Setcreasea purpurea is55.98,Sedum polytrichoides is55.24,Sedum emarginatum is54.60,Sedum alfredi is54.08,Callisia repens is52.47,the heat resistance behaved strong property arranging from strong to weak wereMurdannia loriformis﹥Tradescantia spathacea﹥Sedum lineare﹥Setcreaseapurpurea﹥Sedum polytrichoides﹥Sedum emarginatum﹥Sedum alfredi﹥Callisiarepens.4、Lawn-style green roofs are not only considering the choice of plant but also thesubstrates for them.The research mainly discussed the Sedum lineare substratesscreening in tropic and humid environmental conditions,which aim to providetheoretical consideration and scientific evidence for other green roof plants.Based onthe growth index of Sedum lineare and the physicochemical property of thesubstrates,the result shows the green waste is the best suitable sustrate,Furthermore,anorthogonal experment is adopted to find green waste:perlite:palm fiber is8:1:3and8:3:2and both have a remarkable effect on Sedum lineare growth.The above resules shows that the eight species are all suitable for lawn-stylegreen roof,the substrates screening of Sedum lineare have provide reference for otherspecies.