Effect Of Gradient To Distribute Characteristics And Pull-out Resistance Of Plant Roots On Rock Slopes

Investigate L. bicolor and M. sativa root distribution characteristics on flat and slope conditions with all-dig method, and analysis the diversity between the two site conditions. Measure plants roots pulling-out resistance that on slopes with Hydraulic Pull-tension Meter, and set three experimental treatments about plants roots in this test, analysis the diversity of plants roots pulling-out resistance between three slopes and correlation to root distribution characteristics. Main research results are as follows.1) The change of root branch orders and Ⅱ order roots diameter of L. bicolor is obvious with the gradient increasing. The angle of Ⅰ order roots and slope on60°up-slope increase with the slope gradient. With the slope gradient increasing, the change of root distribution extent and the percent of root that on Up-slope and Down-slope in total root length or root biomass is regularly.The change of diameter of M. sativa taproot and Ⅰ and Ⅱ lateral root is regularly with the slope gradient increase, but the growth direction doesn’t change as the change of slope gradient increasing. The percent of taproot and lateral root length in total length and the percent of roots with diameter0mm<d≤2mm and2mm<d≤5mm in total length change regularly as the slope gradient increase. The diversity of M. sativa taproot and lateral root biomass percent in total biomass is significant between the three slopes (a=0.01).2) The root style of L. bicolor is same on plat and slopes, and the angle of Ⅰ order root and trunk is also same on the two site conditions. But the root branch orders, and the diameter of Ⅱ order root, and the ratio of different diameter root length which on plat is different with root on slopes.The root style of M. sativa is same on plat and slopes, and the growth angle of taproot is also same on two site conditions. But there were difference of taproot diameter and the branch orders and Ⅱ order root of lateral root and the length ratio of root which with diameter2mm<d≤5mm and d>5mm on plat and slopes.3)For L. bicolor roots pulling-out resistance on60°lope, there were difference between the experimental treatments (a=0.05), but there were not significant difference between the experimental treatments on40°slope and5°slope. In addition, for the same experimental treatment, there were not significant difference between the there slopes. For the M. sativa roots pulling-out resistance, there were also not significant difference between the there slopes.For the roots pulling-out resistance of L. bicolor and M. sativa, there is positive correlation to the root length and biomass and so on, but the correlation is not significant difference, and this is maybe related to the special site conditions and special protective measures on slope.We couldn’t ignore the plants’protection to high and steep rock slope, and should be valued. And hope to strengthen the research about roots soil fixation and mechanism to rock slopes.