Applied Research On Four Roof Greening Plants

The climatic conditions of roofs in roof greening are significantly different from those on the ground.Particularly in southern China,rooftops are characterized by strong solar radiation,rapid evaporation of water,and high wind speeds.Therefore,light roof greening is mainly based on resistance to barrenness,heat and drought.Perennial herbs dominate.In the domestic roof greening,the Sedum plants are mainly used,such as Sedum sarmentosum and Sedum lineare,but they have a single community,are easily degraded,are prone to insect pests,monotonous in color,and have poor landscape effects,and are also exposed to high temperature and rain conditions in Guangzhou,Sedum plants are prone to decay.In order to enrich the diversity and stability of roof greening plants and speed up the promotion of roof greening,this article is based on the observation of several types of roof greening plant cultivation.The four types of roofing plants used are Callisia repens,Callisia spiderwort,Portulaca grandiflora,and Portulaca grandiflora'Double Peony'.The test materials were further tested for drought resistance and heat resistance after the previous nursery site cultivation observation.Comparing the strengths of the selected plants,and then researching the propagation technology of 4 plants to determine the production technology of vegetation coils suitable for roof greening plants,and study the matrix materials,substrate thickness,and spreading density of roof greening light vegetation coils in order to develop a suitable vegetation roll product for roof greening applications.The main findings are as follows:(1)The drought resistance tests of four types of roof greening plants were conducted.The relative water content,soil moisture content,relative electrical conductivity,and chlorophyll content of the plants under drought stress were measured.The drought resistance of the four plants was evaluated using a composite function method.The order of strength is:Callisia repens>Callisia Spiderwort>Portulaca grandiflora>Portulaca grandiflora'Double Peony';From the standpoint of drought resistance,the best drought-resistance performance of Callisia repens was the best;the Callisia Spiderwort were used as a new plant source for roof greening,which could complement and enrich the applied species of roof greening plants in Guangzhou;Portulaca grandiflora and Portulaca grandiflora Hook.'Double Peony'are rich in color and have good ornamental qualities.In low-maintenance roof greenery,roof landscape effects can be increased.The four kinds of plants can adapt to the special environment of the rooftops in Guangzhou and have the value of popularizing and applying roof greening.(2)By measuring the MDA content,soluble protein content,soluble sugar content and proline content of four plants at different temperatures,the heat tolerance of four plants treated with 55°C was evaluated by the membership function method.The order of heat resistance is:Callisia repens>Callisia Spiderwort>Portulaca grandiflora>Portulaca grandiflora'Double Peony'.From the ranking of membership functions,the heat resistance of the four plants can be judged.However,the average value of the subordinate plants does not differ greatly.The four plants also have strong heat resistance and can adapt to the test of high temperature environment.(3)Research on the propagation technology of four kinds of roof green plant vegetation to determine the standard production technology applicable to roof greening vegetation volume.The growth traits such as coverage of four kinds of green roof vegetation,vegetation thickness,above-ground biomass,total fresh weight,root cover,vegetation density and dry weight under different substrate types,different substrate thicknesses and different spreading densities were measured.Based on the comprehensive quality analysis,four kinds of roof greening vegetation coils have the most suitable matrix type,suitable substrate thickness,and best spreading density when they have excellent ornamental effects,and they can quickly become flat and save costs.The specific conclusion is:The use of Callisia Spiderwort cuttings 80/0.25m~2 sprinkling density in 4 cm thick mushroom compost matrix highest quality,reaching 5.48;The spreading density of Callisia repens cuttings of 100/0.25 m~2 was the highest on the composting base of 4 cm mushrooms compost,reaching 6.21;With Portulaca grandiflora cuttings of 100/0.25m~2sprinkling density in 4 cm thick mushroom compost matrix highest quality,reaching6.37;With the use of Portulaca grandiflora'Double Peony'cuttings of 100/0.25 m~2sprinkling density in 2 cm thick mushroom compost matrix highest overall quality,reaching 5.16.