Study On The Growth Suitability Evaluation And Landscape Construction Methods Of Common Shrubs And Grass Plants In Underground Space Of Central China

With the large-scale development and utilization of underground space,people’s behavior and activities in underground space are gradually increasing.Through literature review and field research,it was found that underground spaces have problems such as poor environment,idle space,and lack of organization.Plants have multiple ecological,aesthetic,and social values,which can help alleviate these problems.However,the plant landscape types in underground spaces are single,lacking spatial organization,and there are few related practices.Therefore,in order to improve the quality of underground space environment,improving plant elements can enhance the spatial environment and function.After analyzing relevant cases both domestically and internationally,and conducting underground plant landscape research on 4 subway stations and 8 surrounding shopping malls in Wuhan,54 plant species were recorded.However,most of them were indoor foliage plants originating from tropical and subtropical regions,such as Epipremnum aureum and Pachira glabra.Only 2 species were native to central China,and their application frequency was much lower than other plants.In addition,the configuration of plants in underground spaces is mainly based on potted plants and combinations of potted plants,and the planting methods and configuration forms are not rich enough.This study attempts to screen and evaluate suitable local shrub and grass plants for use in underground spaces,in order to guide the construction of plant landscapes in underground spaces.First,the list of commonly used shrub and grass plants in central China was obtained by statistics,and the plants were divided into upper,middle and bottom levels according to the vertical height level.Then,the python algorithm was written to preliminarily screen the combination of plant community.According to the flora of China,the data of plant flowering and fruiting period and plant height range were collected,so that the highest plant height of plants on the lower floor was lower than the lowest plant height of plants on the higher floor,avoiding plant canopy overlap.Considering the flowering and fruiting ornamental period of plant combinations,some plants were selected as plant species for this planting.Based on the screening results and the convenience of procurement,sexual selection were selected,and finally 23 commonly used shrub and grass plants in central China were obtained.Based on the selected plant species,this study further evaluates the adaptability of plants under different light intensities.Set different experimental groups by using LED plant fill lights to control the distance of the light source.At the same time,considering the comfort of human eyes and referring to the light intensity parameters set by the lighting criteria for underground structure,this study set up two groups of different light treatment experimental groups under the original light conditions.Through the continuous recording of plant growth status and plant height,crown width,SPAD values in different light treatment groups,the change chart of plant growth data was drawn,and the growth data was analyzed using single factor variance,Summarize its adaptability to different lighting conditions and underground space environments.Then,the Analytic Hierarchy Process was used to construct an evaluation system for the suitability of underground space plant landscapes,and the plant suitability was scored.The overall results show that in the upper plants,there are Nandina domestica,Hibiscus syriacus,and Gardenia stenophylla;in the middle layer white fern,phoenix tail fern,and Ophiopogon japonicus;In the bottom layer,Viola philippica,Trachelospermum jasminoides ’Flame’,Hedera nepalensi,Oxalis corymbosa,and Tiarella polyphylla performed relatively well.Among them,there were phenological changes such as flower bud differentiation after planting Viola philippica and Tiarella polyphylla,indicating high landscape value.For the lighting environment provided in the experiment,high light has a significant effect on the growth of the shrub layer and can also delay the decay and death of some plants;About 45.5%and 80% of the surviving middle and lower level plants perform better under medium light conditions,and some even grow better under low light conditions.When constructing a light environment for plant growth in underground spaces,appropriate light intensity should be selected according to the needs of the landscape subject.Finally,based on the functional positioning and planting environment conditions of underground space,this study summarizes plant layout patterns from three spatial bases:bottom,facade,and top.Based on experimental results,plants with higher suitability or better ornamental value are selected to provide examples of plant combinations in underground space.