The Effects On Root Morphology For Different Breeding Seedling Patterns And Cutting Roots

How vegetation ecological function play doesn't only depend on the coverage of the surface, but also on its structure ,especially the structure of the underground roots system. The research realize that planting by stock have interfered the physiological equilibrium of the plant, but direct seeding is with the establishment mechanism of the natural forests (natural plant community) and short the time of natural plant establishing course. At the foundation, it explore the diversity of roots development for different seedling form and cutting roots, and other physiological characteristic differences and growing differences caused by that diversity.The purpose is to probe into the forming and promoting mechanism of strong roots of forestation varieties and to offer the good theoretical foundation for establishing afforesting technology system and resuming the natural ecosystem, following the natural plant establishing mechanism. The main results are as follows:1. Carrying on the injury of the main root to the tree can inhibit the growth of the main root, promote the emergence of lateral root, accelerate the extension pace of lateral root and heighten the position of lateral root. The change scope of the root system index ,compared with which are not cut the roots, is concerned to the proportion of the main root which are cut. And for different species, the change scope of the index is different.2.The seed-base can promote the formation of vigorous and healthy root system. It can promote roots to grow to the gravity direction along the hole in the seed-base. The main root is developed, the lateral root is sturdy and distribute evenly. But nutritive bowl limit root system's nature growth for the narrow and small space. The main root is not obvious, the angle of the lateral root is too big and plant's roots are often coiled.3. Carrying on the injury of the main root to the tree can restrain trees to grow thickly, the inhibitory action of the main root cut 1/2 is to be most obvious. The main root cut 1/3 is able to promote trees' upside growth and cause the height increase. But the main root cut 1/2 inhibit trees' upside growth in a certain degree and cause the height reduce. There are not remarkable difference in every pattern of Platy cladusorientalis , Robinia pseudoacacia L. and Ulmus pumila Linn.4.Compared with nutritive bowl seedling, the seed-base can promote the upside growth. That is related to the seed-base can promote the infrastructure. For different species, the height increase differently. Because the seed-base were put in the seedbed barely and the moisture disappear quickly, the superiority of the diameter is not obvious and only Robinia pseudoacacia L seedlings disaplay the superiority. The difference of root/shoot ratio is not remarkable between the seed-base seedling and the nutritive bowl seedling.5.After the main root was cut, there is the certain difference of the photosynthetic rate (Pn) with the comparison. That is related to the proportion of the main root which are cut. c there is remarkable diversity between the main root cut 1/2 and 1/3. Ulmus pumila Linn., there is remarkable diversity between the main root cutl/2 and comparison and the main root cut 1/3 and comparison. After the root was cut, the transpiration rate (Tr) of all pattern is...