An Applied Experiment Of Various Seedling Sources Of Virescence Trees In Harbin City

With the increasing process of urbanization, urban environment has been becoming a notable question. It has been influencing the health of citizen and the sustainable development of economy. Garden ivresc-ence is becoming more and more important in constructing city and its ironment. The development of Garden virescence has gone through two stages from virescence to beaut ification.Chinese government have been quickening the step of implementing the reform and open policy. It widened the field of vision of Chinese. And then, the style of Garden virescence is becoming more and more diversil'icat ion as well as the style of people's living. Layout of Garden virescence is also from rigidification to freedom and flexi- bleness. More and more plant species has been adapted in Garden vir- escence than ever before. Ordonnance of plant in Garden virescence is more adjusted measures to local conditions. Arrangement is becoming more and more appropriate.However, every species has its own characteristics, and itsre-quest of environment is also different from others. All the plant species has its own geographical distributing area and their growth condition is also different a lot. Improper choosing virescence species would result in decreasing its growing, bringing abnormal crown of tree, making branches and leaves dry, producing plant diseases and insect pests, being frozen in big area, decreasing its function of ecology. It may not improve and beautify the city's environment and even bring some bad impacts, herefore, to choose proper virescence species and the area of seedling source would improve its survival rate and reinforce the beautiful impression of city. It would advantage the city constructing and economy progressing.In this thesis the distribution area, germinant rate in each field, height growth and diseases and insect pests condition of virescence species was studied by using the method of gray evaluation and efer-encing the study result of introducing new species in forest, as wellas the study and analysis of different species were planted in the same field, and identical species was planted in different field, we get the result which is as follows: the characteristics of virescence species is different evidently between each species source, the typi- cal characteristic of main species between each species sources is variance discontinuously, the virescence species from west such as Qiqihaer, Heihe and south Jixi, Mudanjiang is adaptive more, the see- dling from Harbin or its nearby has comparative high survival rate but low preservative rate. This study would provide reference in choo- sing virescence species and introducing into seedling in Harbin city.