Selection Of Roof Greening Plants And Heat Resistance Assessment In Fuzhou City

Fuzhou is known as"Rong cheng, Hot Springs". In recent years, because of the urbanization process accelerated, the rate of urban green space turns less, "heat island effect" become severe. At present, the scarcity of urban land has become the biggest challenge of urban greening, in order to address the conflict which is the demand for green space and urban construction land, roof greening become a focus of attention at home and abroad. In this paper, combining the climatic conditions in Fuzhou, about choosing the plants and substrate for roof greening, we assess heat resistance of the greening of the roof of the main - plants to look for suitable green roof plants as reference. results showed that:1. Observate roof and ground of weather indicators in spring, summer, autumn and winter, such as temperature, humidity light intensity and so on, one of which the summer temperature difference is the most significant. Roof, whose temperature changes quickly, has the heat small capacity, easy heat absorption and easy heat elimination, and low relative humidity air. In summer, the maximum temperature of the ground is 37～39℃and the roof's is up to 50℃.Therefore high temperature is an important factor for the normal growth of plants.2. According to choosing the culture medias for eight kinds of greening plants (Sedum lineare,Sedum sarmentosum,Sedum rhodiola,Sedum alfredii,Gardenia jasminoides,cv.prostrata,Brunfelsia acuminata,Murraya paniculata), different combinations of culture medias have a very significant impact for eight kinds of greening plants'relative growth rate. we can derive a better ratio for culture media of Sedum lineare,Sedum sarmentosum,Sedum rhodiola and Murraya paniculata are peat:Huang Xin soil=2:2, Sedum alfredii,cv.prostrata,Gardenia jasminoides'are peat:Huang Xin soil: Vermiculite= 3:2:1, Brunfelsia acuminata'is peat:Huang Xin soil=3:1.3. After high-temperature menace, the eight kinds of roof greening plants' relative conductivity with the increase in heat stress, is increased to varying degrees, of which Sedum lineare,Sedum sarmentosum are relatively small increase in electrical conductivity, whereas cv.prostrata' is the largest increase. According to the relative change in conductivity, we can use the Logistic equation to determine the semi-lethal temperature plants of Sedum lineare,Sedum sarmentosum,Sedum rhodiola,Sedum alfredii,cv.prostrata,Gardenia jasminoides,Murraya paniculata,Brunfelsia acuminata:57.15℃,56.36℃,56.08℃,54.19℃,48.86℃,51.24℃,51.97℃,52.66℃.4. Different heat treatments have a very significant effect on the eight kinds of roof greening plants'the content of MDA, while different heat treatments have a more significant effect on the eight kinds of roof greening plants'the eight kinds of roof greening plants'chlorophyll content, PRO content, relative water content; after high-temperature menace, their chlorophyll content and relative water content are overall downtrend; while MDA content and PRO content are overall uptrend.5. By measurating the above-mentioned plants'chlorophyll content, malondialdehyde content, free proline content and relative water content and semi-lethal temperature so on, and combining the general evaluation to the heat-resistant of eight kinds of plants with membership function, the results show that the heat-resistant of Sedum rhodiola,Sedum lineare,Sedum sarmentosum is higher, while the heat-resistant of Sedum alfredii, Gardenia jasminoides,Brunfelsia acuminate is lower.