Investigation Of Spontaneous Herbaceous Resources And Evaluation Of Garden Utilization Value In Jingzhou Main Urban Area

Spontaneous herbaceous plants in cities are rich in species and have the advantages of barrenness tolerance,adaptability,low maintenance and low cost.They play an important role in improving urban biodiversity,improving urban microclimate and creating regional plant landscapes.Currently,the acceleration of urbanization has gradually reduced the natural environment in cities that can provide for the growth of spontaneous herbaceous plants.The ecological and ornamental value of spontaneous herbaceous plants has not received sufficient attention in urban construction.Therefore,it is important to fully understand the species composition characteristics and ornamental features of urban spontaneous herbaceous plants to create an urban landscape with ecological and ornamental values in the context of ecological sustainability.In the present study,the spontaneous herbaceous plant resources in the main urban area of Jingzhou were investigated by sample and pedestrian survey method from August to October 2021 and from March to May 2022 to understand the species composition and distribution characteristics of the spontaneous herbaceous plants.On this basis,analytic hierarchy process(AHP)hierarchical analysis was used to evaluate the landscape use value of 78 spontaneous herbaceous plants in order to provide reference for biodiversity research and development and utilization of spontaneous herbaceous plant resources in the main urban area of Jingzhou.The results of the study are as follows:(1)A total of 352 species of 236 genera in 70 families were investigated in Jingzhou,among which Gramineae and Asteraceae were the most abundant species;dwarf growth types were dominant,with a balanced number of species of annual and biennial herbs and perennial autochthonous herbs;.There were 298 native species in China,accounting for 84.65% of the total species,and 54 non-native species in China,accounting for 15.35%.In spring,the dominant species were Oxalis corniculata,Poa annua and Veronica persica.Digitaria sanguinalis,Euphorbia humifusa,Oxalis corniculata,Alternanthera philoxeroides and Eleusine indica were the dominant species in autumn.(2)According to the distribution characteristics of each habitat,the number of spntaneous herbaceous plant species in wasteland was the largest;The composition of dominant spontaneous herbaceous species in different habitats was different.The dominant species in spring and autumn were Alternanthera philoxeroides,Cyperus rotundus and Oxalis corniculata.Oxalis corniculata was dominant in spring and Digitaria sanguinalis was dominant in autumn.The distribution of spontaneous herbaceous species in each habitat was U-shaped,and the number of herbaceous species distributed in single habitat and six habitats was higher.From the perspective of growth type,dwarf growth type is dominant,while from the perspective of life type,except for the wasteland where perennial herbaceous are more than biennial herbaceous,other habitats are dominated by biennial herbaceousAccording to the distribution characteristics of the urban green space system,the number of spontaneous herbaceous in transportation facilities land(SG)was the largest.There were 16 dominant species in spring and autumn,Oxalis corniculata was the dominant species in spring and Digitaria sanguinalis was the dominant species in autumn.The number of species distributed in category 2-9 green space system was the largest.Biennials and dwarf growing herbaceous plants are dominant in urban green space systems.(3)In terms of diversity patterns,a moderate level of anthropogenic disturbance had a positive effect on species diversity.The mean number of species was highest in the sample of wasteland,and the Shannon-wiener index was higher in building abandoned and unused land;the mean number of species was highest in the sample of productive greenland(EG4),and the Shannon-wiener index was higher in greenland attached to road and transportation facilities land(SG)and greenland attached to residential land(RG).In terms of similarity patterns,the species composition of native herbaceous plants in the main urban area of Jingzhou was higher in each habitat,and the species composition of native herbaceous plants was higher in the green space attached to residential land(RG)and the green space attached to road and transportation facilities land(SG).In terms of urbanization,the Shannon-wiener index was higher in low-urbanized areas than in medium-and high-urbanized areas;the spontaneous herbaceous plants composition was less similar in high-and medium-urbanized areas than in low-urbanized areas.(4)The garden utilization value of 78 selected spontaneous herbaceous was evaluated by AHP,which was divided into 4 grades according to their total scores.Grade Ⅰ was the total score ≥ 3.30,and there were 10 kinds of spontaneous herbaceous in this grade.They are Lysimachia christiniae,Torilis scabra,Artemisia argyi,Duchesnea indica,Euphorbia humifusa,Cnidium monnieri,which species of ecological and ornamental value can be used in landscape.The second grade was 2.90≤ total score < 3.30,and there were 34 kinds of spontaneous herbaceous in this grade.They are mainly ornamental species such as Eragrostis pilosa,Lactuca sibirica,Clinopodium chinense,Rumex dentatus,etc.,which can be moderately promoted and applied.The third grade was 2.50≤ total score < 2.90,and there were 24 species of spontaneous herbaceous in this grade,including Cyperus iria,Geranium sibiricum,Equisetum ramosissimum,etc.The suitable environment should be chosen according to its growth characteristics.Grade Ⅳ is the total score < 2.50,and the spontaneous herbaceous plants of this grade can not be considered for development and application.Jingzhou main urban area has rich spontaneous herbaceous plant resources.On the basis of understanding the species composition characteristics,distribution characteristics and garden utilization value of spntaneous herbaceous plants,establishing ecological concepts and selecting appropriate species for plant planting design can effectively reduce the cost of management and improve the biodiversity and ecological sustainability of the city.