The Heterogeneous Habitat Of Bamboo In Chengdu Greenland System And Effects Of Clonal Integration On Adaptation To Heterogeneous Light Environment

Bamboo plants have a long history of application in Chinese gardens and play an extremely important role in the construction of classical gardens and the construction of modern ecological cities.Researches on the application of existing bamboo plants in gardens have focused on the arrangement of bamboo plants and the creation of artistic conception,the cultural connotation and aesthetic characteristics of bamboo plants,etc.The understanding of the relationship between the unique growth characteristics of bamboo plants and the habitat of bamboo plants is not yet clear.Based on this,the paper is based on field research on the application forms and growing environment of bamboo plants in different types of green space in Chengdu.The habitat heterogeneity characteristics of bamboo plants in Chengdu green space were summarized,and the adaptation effects of the growth characteristics of bamboo plants on the heterogeneous light environment of Phyllostachys bissetii were studied.Get the following results:（1）Bamboo plants are widely used in Chengdu green space systems:Bamboo plants are used in different types of urban green space:park greenbelts,protective greenbelts,production greenbelts,affiliated greenbelts,and other green spaces.They are used most frequently in park greenbelts,and they are used less frequently in production greenbelts,and their growth status is generally well.（2）The growth environment of bamboo plants in the green space system of Chengdu has a wide range of heterogeneity:Through the investigation of the growth environment of bamboo plants,it is concluded that the growth environment of bamboo plants is various,and the distribution of plant species in the open space,semi-open space and closed space is all.The diverse spatial distribution means that the bamboo plant living environment has a wide range of light environment,soil environment and heterogeneity of the water environment.（3）Cloning integration can reduce the effect of weak light environment on photosynthesis of Phyllostachys bissetii by changing the photosynthetic nitrogen distribution pattern of Phyllostachys bissetii shading.The study is based on single axillary type bamboo plant——Phyllostachys bissetii clone fragment through the basin pick test,and the nitrogen allocated to the leaf of Phyllostachys bissetiia as the research content.In addition,the proximal branches are under natural light conditions,and the distal branches are in the shade environment.The effects of clone integration on the distribution patterns of photosynthetic nitrogen in the distal and proximal branches were studied by means of cutting or not cutting the rhizomes.Test results show:1)When grown in shaded ramets,connected with an unshaded mother plant,displayed higher potential maximum net photosynthetic rate(P_max),leaf nitrogen（N_M and N_A）,chlorophyll concentration and total partition coefficients of leaf nitrogen in photosynthetic apparatus（P_T）than severed ramets;2)The connected apical ramets had higher partition coefficients of leaf nitrogen in carboxylation components and bioenergetics components than in light-harvesting components;3)There were no significant differences in leaf mass per area and nitrogen content between the two treatments of connected and severed proximal ramets in natural lighting conditions,while connected ramets displayed higher P_max,P_T and chlorophyll concentration.The results suggest that the rhizomes remain connected so that the branches in the shaded habitat have stronger photosynthetic capacity;The integration effect increased the distribution of total photosynthetic nitrogen in the shade,thus alleviating the weakening of photosynthetic capacity of Phyllostachys bissetii.It is believed that the special growth characteristics of bamboo plants,clonal integration,allow the cloned ramets in adversity to have higher photosynthetic capacity,which is beneficial to the survival and growth of cloned fragments in heterogeneous habitats.This may be an important material basis for the widespread use of bamboo plants in landscapes.