Investigation And Analysis Of Three Parks Ground Cover Plant In Tianjin

With the development of urban parks,ground cover plants are widely applied in city greening for landscaping,soil and water conservation,and air purification.As one of the biggest metropolitan in China,Tianjin has attached great importance to improving living condition and sustainable development of landscape.To investigate plant species composition and diversity,3 representitive city parks were selected: Tianjin Water Park,Bridge Park and Xiqing Country Park.A total of 21 plots were investigated,richness,dominance,diversity and evenness index were analyzed,comprehensive the quality of ground cover plants were evaluated.Main results are as follows:1)A total of 148 species ground cover plants were recorded in 3 city parks,which belongs to 120 genera and 51 families.Herbaceous,woody,vine and bamboo ground cover accounts for 71.5%,17.2%,10% and 1.3% of the total,seperately.Utilization rate of native species is relatively low,accounting for 37.7% of the total.Application rate of ornamental plants are as follows: flowering plants>foliage plants >fruits plants.From ecological prospective,Bridge Park is better than Tianjin Water Park and Xiqing Country Park.2)The proportion of woody plants was relatively low,importance values of herbaceous ground cover plants were rated.According to their importance value,the top 5 ground cover plants for 3 parks were Pennisetum alopecuroides,Iris lacteal,Phalaris arundinacea,Gaura lindheimeri Engelm,Physostegia virginiana in Bridge Park,Porrtulaca grandiflora,Hosta plantaginea,Tagetes erecta,Coreopsis drummondii Torr,Celosia cristata in Water Park;Medicago sativa,Sedum aizoon,Setaria viridis,Iris lactea Pall,and Aster novi-belgii in Xiqing Country Park.Abundance index of 3 parks were not significantly different.Dominance index of Xiqing Country Park is much higher than that of Bridge Park and Water Park,but Simpson,Shannon-Wiener and Pielou index were significantly lower;richness,diversity and evenness index of 2/3 plots at Bridge Park were above average level;richness and diversity index of 2/7 plots at Water Park above average level,but their evenness index were relatively low.It is concluded that species richness and diversity were highest at Bridge Park,and plant community was stable;species richness and diversity at Water Park were comparatively high too,but evenness index was low;species diversity at Xiqing Country Park was low,and dominance index was the highest amongst 3 parks.3)The order of controlling factors for ground cover plants in 3 parks during co mprehensive quality evaluation were: ornamental factor> application factor> ecological factor.According to their ecological adaptability,coverability and ornamental effects of35 ground cover plants,6 of them were classified as Grade ?,16 as Grade?,12 a s grade ? and 1 as Grade ?,accounting for 17.1%,45.7%,34.3% and 2.9% of the total respectively.Obviously,most ground covers plants at 3 parks were classified as top 3 Grade in the evaluation of comprehensive quality.