Studies On Root Niche And Slope Protection Performance Of Different Root Types Combinations Patterns

The root system is an important organ of vegetation and soil connection in slope vegetation restoration,and different plant combinations can improve slope stability.However,there is a certain blindness in the plant configuration at present.We studied the effect of different root types combined plants on slope ecology and slope protection function in order toreducing plant allocation blindness.In this experiment,four kinds of plants with different root types(vertical axis root type,horizontal axis root type,root tiller type and cluster type)were selected to carry out designs:Festuca elata ? Amorpha fruticose+ F.elata.?Lespedeza bicolor+ F.elata.?A.fruticose+ L.bicolor.?Medicago sativa.?A.fruticose + M.sativa?A.fruticose+ L.bicolor+ F.elata.?L.bicolor?A.fruticose.Bare ground was used as control,the vertical spatial distribution characteristics,niche characteristics and slope protection performance of different combination roots were studied by simulating slope planting in order to provide reference for slope plant configuration.The main results of this experiment are as follows:(1)The soil moisture content and soil porosity of different combinations were about 1-3 and 0.1-0.5 times of the control,respectively.The spatial distribution of root system was closely related to ecology and slope protection function.(2)The percentage cm root length of " F.elata " and " L.bicolor+ F.elata"," A.fruticose+ M.sativa " and " M.sativa " were smaller in the soil layer of 0-10 cm.The comparative advantage combination of root and stem weight was " L.bicolor ".The overall root density decreased with the increase of soil depth.Size was: " F.elata ">" L.bicolor+ F.elata ">"A.fruticose+ L.bicolor+ F.elata.">" A.fruticose+ M.sativa ",There was no significant difference in other combinations.When the accumulation amount was 80%,the root weakening coefficient was higher than other combinations,such as " L.bicolor+ F.elata "," L.bicolor " and " A.fruticose+ L.bicolor+ F.elata.".The largest combination of specific root length and specific root area in the whole soil layer was " L.bicolor+ F.elata " and " F.elata ",and the smallest was" L.bicolor ";The root-crown ratio size was " L.bicolor ">" A.fruticose ">" A.fruticose+ M.sativa ">" A.fruticose+ L.bicolor ">" M.sativa ">" A.fruticose+ L.bicolor+ F.elata.">" L.bicolor+ F.elata.">" A.fruticose+ F.elata.” >" F.elata."(3)The distribution pattern of soil layer and diameter of niche index was divided into five types: standard type,inverse J type,V type,J type and inverted J type.The largest niche index was " A.fruticose+ L.bicolor "," A.fruticose + M.sativa "," M.sativa " and "A.fruticose+ L.bicolor " accounted for 94.49%,87.30% and 79.32% respectively.The niche width of the thick root was higher than that of the other combinations was“A.fruticose+ L.bicolor+ F.elata”,The niche overlap value and the competition index between underground species tend to be the same,among which the " A.fruticose+ L.bicolor " and " M.sativa " are in the middle level,which was more advantageous.(4)The values of moving soil,the first fracture value and the maximum tensile force were all the largest,which were " A.fruticose+ L.bicolor+ F.elata " and " A.fruticose+ L.bicolor",The size was about 2-3 times that of the smallest combination of " A.fruticose " and " A.fruticose + F.elata ",followed by " A.fruticose+ M.sativa " and " M.sativa ".The tensile strength was opposite to the process force.In summary,the better combination of vertical spatial distribution of roots were " vertical axis root type+ horizontal axis root type+ cluster type " and " horizontal axis root type+ cluster type ";The better combination of niche features were " vertical axis root type+ horizontal axis root type+ cluster type "," vertical axis root type+ horizontal axis root type "," root tiller type+ root tiller type " and " vertical axis root type + root tiller type ";The better combination in stability were " vertical axis root type+ horizontal axis root type+ cluster type " and " vertical axis root type+ horizontal axis root type ".