Influencing Factors Of The Shoots Shriveling Of The Platanus In North China

Platanus has good ornamental, adaptable, fewer pests and diseases. Purify the air, regulating climate also can improve the urban culture to enhance the taste of the city, so the higher application rate in the urban landscape greening tree species, a large garden green space planted in city parks, squares and streets. In recent years, the city of North China shoots shriveling of Platanus phenomenon has been frequent occurrence, has become the biggest obstacle restricting the application of Platanus, also seriously affected the landscape effects of Platanus. In order to find the key to the shoots shriveling of Platanus to garden plants in the future conservation and management of scientific and effective theoretical basis to avoid after Platanus on the conservation and management of the development of blind conservation measures to achieve the efficient and orderly labor management provide the basis for the study, the shoots shriveling of Platanus.(1) In recent years,the Platanus has the large shoots shrivelling condition in North China. Thought the Research of Platanus’ diameter at breast height,growth environment,species and shoots shrivelling investigate in Shijiazhuang, Baoding and Langfang cities.And divide the shoots shrivelling level. The results showed that, Shijiazhuang,Baoding,Langfang shoots shrivelling incidence of 15.46%,25.59% and 43.72% respectively. From south to north was gradually increasing trend. The gap between the east and west sides of the north-south road is almost the same.The south’s shoots shrivelling incidence is higher than the north side of the road. The different forms have very little influence on the shoots shriveling.And the gap between the tree pool and the strip green belt is less than 2%.(2) By comparing the bulk density of the soil, water content and roots with the critical and normal Platanus,found that water content of the soil is not the main reason of shoots shriveling to Platanus.Platanus which has the different grading of shoots shrivelling are in different density of the soil. There is a huge gap between the vertical and horizontal with differing roots’ amounts of shoots shriveling.The root which is normal is mainly distributed in the 0~40cm layer.And the root projection exceeds the crown projection.But the roots which is badly shoots was mainly in 0~20cm layer, and the root projection less than the crown projection.(3) Four kinds of Platanus(Platanus occidentalis, Platanus acerifolia, Platanus orientalis and Platanus acerifolia ’Fast-crebrescens’) were taken as the experimental material to explore water content and extraction of the branches, the relationship between the critical water content and shoots shriveling of the branches. The results showed that the safe wintering Platanus’ water content had a trend of decline after rising first. In 2014, loss of water of four kinds of Platanus branches mainly happened during February 19 to March 1. The water content of safe wintering dormant branches’ water content were extremely significant negative correlated to the conductivity(r=-0.777**).The critical water content test of Platanus’ branches showed that the critical water content of the Platanus occidentalis, Platanus acerifolia and Platanus orientalis was from 40% to 35%. Also, the test declared that Platanus acerifolia ’Fast-crebrescens’ ’s shoots shriveling resistance was stronger with critical water content which is from 35% to 30%.(4) Studing the changing of dormancy in Platanus soluble protein and soluble sugar content with Platanus acerifolia and Platanus acerifolia ’Fast-crebrescens’, The results show that, in the critical period of the water, The content of soluble protein of Platanus acerifolia ’Fast-crebrescens’,is higher that Platanus acerifolia,but the content of sugar is lower that Platanus acerifolia.(5) Studing the low temperature stress in each month of four kinds of Platanus’ semi lethal temperature. The results show that, with the winter temperature in different months decreased first and then increased, semilethal temperature also showed the same trend. Platanus acerifolia has the higher cold resistance than the other three.But the lowest temperature is higher than Platanus’ semi lethal temperature. So the low temperature in winter is not the main reason of the shoots shriveling.